review article beyond standard model searches in the...

Review ArticleBeyond Standard Model Searches in the MiniBooNE Experiment

Teppei Katori1 and Janet M Conrad2

1Queen Mary University of London London E1 4NS UK2Massachusetts Institute of Technology Cambridge MA 02139 USA

Correspondence should be addressed to Teppei Katori tkatoriqmulacuk

Received 31 March 2014 Accepted 5 August 2014

Academic Editor Abhijit Samanta

Copyright copy 2015 T Katori and J M Conrad This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited The publication of this article was funded by SCOAP3

The MiniBooNE experiment has contributed substantially to beyond standard model searches in the neutrino sector Theexperiment was originally designed to test the Δ1198982 sim 1 eV2 region of the sterile neutrino hypothesis by observing ]

119890(]119890) charged

current quasielastic signals from a ]120583(]120583) beam MiniBooNE observed excesses of ]

119890and ]

119890candidate events in neutrino and

antineutrino mode respectively To date these excesses have not been explained within the neutrino standard model (]SM) thestandard model extended for three massive neutrinos Confirmation is required by future experiments such as MicroBooNEMiniBooNE also provided an opportunity for precision studies of Lorentz violation The results set strict limits for the first timeon several parameters of the standard-model extension the generic formalism for considering Lorentz violation Most recently anextension to MiniBooNE running with a beam tuned in beam-dumpmode is being performed to search for dark sector particlesThis review describes these studies demonstrating that short baseline neutrino experiments are rich environments in new physicssearches

1 Introduction

Across the particle physics community the mysterious peri-odic-table-like nature of the standardmodel (SM) is motivat-ing searches for new particles new forces and new propertiesof the particles that are knownThe neutrino sector is provinga rich environment for these searches Having already foundone beyond standard model (BSM) effect neutrino mass [1]a series of experiments are pursuing other potential signalsUnlike the case of three-neutrino oscillation measurementswithin ]SM many of these searches are pursued over shortbaselines from a few meters to approximately a kilometerThe Mini Booster Neutrino Experiment (MiniBooNE) atFermi National Accelerator Laboratory (Fermilab) is anexcellent example having contributed substantially to BSMstudies

This review describes the MiniBooNE BSM programWebegin by describing the experiment This is followed by adiscussion of the MiniBooNE cross section studies whichhave been essential input to both the BSM searches withinthis experiment and also to other experiments including T2K

most recently [2] We then describe three searches the sterileneutrino search which motivated the experiment Lorentzviolation searches which set the first limits on five neutrinosector parameters and the search for dark sector particleswhich is now being pursued with a reconfigured beam

2 MiniBooNE Experiment

MiniBooNE (running from 2002 to 2012) was originallydesigned to test the LSND signal [3] In the LSND exper-iment low energy (0 to 53MeV) muon antineutrinos wereproduced by pion decay-at-rest (DAR) and were detected bythe liquid-scintillator-based LSND detector at 31m from thetarget The observed 38120590 excess of ]

119890candidate events could

be interpreted as oscillations in the Δ1198982 sim 1 eV2 regionwithin a simple two massive neutrino oscillation hypothesiswhere the oscillation probability is given by

119875 (]120583997888rarr ]119890) = sin22120579sin2 (127Δ119898

2119871

119864) (1)

Hindawi Publishing CorporationAdvances in High Energy PhysicsVolume 2015 Article ID 362971 19 pageshttpdxdoiorg1011552015362971

2 Advances in High Energy Physics

Booster Targethall

TevatronMain injector

(a) (b)

BoosterTarget

andhorn Decay

region Earth Detector

Primary beam Secondary beam Tertiary beam

(protons) (mesons) (neutrinos)

120587

120583

(c)

Figure 1 The MiniBooNE experiment layout [4] (a) The Fermilab accelerator complex (b) The MiniBooNE detector with inset showingthe black inner volume and the white outer volume (c) Schematic layout of the beam and detector [18]

Here 120579 and Δ1198982 are oscillation parameters to control the

amplitude and the period respectively (further discussed inSection 4) 119871 is the distance from neutrino production tointeraction in meters and 119864 is the energy of the neutrino inMeV

An experiment which maintains the same 119871119864 ratioshould observe an oscillation probability consistent withLSND if the simple two neutrino model is a good approx-imation of the underlying effect However by employingan average 119864 which is an order of magnitude larger thanLSND the systematic errors associated with production anddecay are quite different If 119871 is increased accordingly and nosignal is observed this rules out the two-neutrino oscillationhypothesis of the LSND result

MiniBooNE was designed with this in mind The Mini-BooNE beam peaked at sim700MeV and the Cherenkovdetector was located at sim500m baseline Figure 1 shows anoverview of theMiniBooNE design [4] and in the remainderof this section we provide more details

21 Booster Neutrino Beam-Line The Booster NeutrinoBeam-line (BNB) extracts 8 GeV kinetic energy protonsfrom the Fermilab Booster a 149m diameter synchrotron(Figure 1(a)) Eighty-one bunches separated in time bysim 19 ns are extracted by a fast kicker within a sim16 120583s pulseEach pulse contains around 4 times 10

12 protons Typically fourto five pulses per second were sent to BNB to produce theneutrino beam

This high intensity proton pulse collides with a berylliumtarget to produce a shower of mesons (Figure 1(c))The targetis located within a magnetic focusing horn For neutrino

mode running the toroidal field generated by the hornfocuses on positive mesons with 120587+ decay-in-flight (DIF) asthe primary source of the ]

120583beam In antineutrino mode

running the horn focuses on negative mesons to create the]120583dominant beam The details of the BNB neutrino flux

prediction can be found in [5]MiniBooNE collected 646 times 10

20 proton-on-target(POT) in neutrino mode and 1127 times 1020 POT in antineu-trino mode

22 The MiniBooNE Detector The MiniBooNE detectorlocated 541m away from the target is a mineral-oil-basedCherenkov detector The 122m spherical tank filled withpure mineral oil (CH

2)119899 has two optically separated regions

The interior region lined by 1280 8-inch photomultipliertubes (PMTs) contains the target volume An outer volumeequipped with 240 8-inch PMTs serves as the veto region [6]The presence of a charged particle above threshold is detectedthrough the Cherenkov radiation observed by PMTs As seenfromFigure 1(b) the inner volume is painted black to preventscattering of the Cherenkov light improving the reconstruc-tion precisionOn the other hand the outer volume is paintedwhite to enhance scattering of Cherenkov light in order toachieve the 999 rejection of cosmic rays by the veto [7]even with fairly sparse PMT coverage The charge and timeinformation from all PMTs is used to reconstruct kinematicsof charged-lepton and electromagnetic events MiniBooNEmineral oil produces a small amount of scintillation lightwhich can be used to reconstruct the total energy of theinteraction via calorimetry which is particularly importantfor particles below Cherenkov threshold

Advances in High Energy Physics 3

Interaction Track Cherenkov Candidate

Neutral pion

NC120587∘

Muon

Electron

120583 CCQE

e CCQE

+ N rarr + N + 120587∘

120583 + n rarr p + 120583minus

e + n rarr p + eminus

Figure 2 (Color online)MiniBooNE particle reconstruction [4] From top to bottom amuon neutrino charged-current quasielastic (CCQE)interaction an electron neutrino CCQE interaction and a neutral current neutral pion production (NC1120587∘) interactionThe second and thethird columns show the characteristics of tracks and Cherenkov rings [7] and the last column shows the event displays of candidate events

For the ]120583rarr ]119890(]120583rarr ]119890) oscillation study the follow-

ing three particle reconstruction algorithms were the mostimportant single Cherenkov rings from (1) a muon and (2)an electron and the two-ring electromagnetic shower topol-ogy from (3) a neutral pion decay to two gammas Figure 2shows the different characteristics of these three signalsincluding examples of typical events in the detector [4]

The reconstruction algorithms can also reconstruct morecomplicated topologies important for constraining back-grounds and for cross section studies discussed below Thecharged-current single charged pion (CC1120587+) interactionreconstruction algorithm [8] fit two Cherenkov rings fromfinal state particles a charged lepton and a positive pionto find their kinematics The charged-current single neutralpion (CC1120587∘) interaction reconstruction algorithm [9] fita charged lepton and a neutral pion (which consists oftwo electromagnetic showers that is the algorithm fits forthree Cherenkov rings) Another algorithm identifies andreconstructs the neutral current elastic (NCE) interaction[10] where the total kinetic energy of final state nucleons isfound using scintillation light

Along with reconstruction of the light topology in thedetector event identification also relies upon ldquosubeventsrdquoThese are bursts of light separated in time which indicatea sequence of decay For example a muon which stops andthen emits a decay (ldquoMichelrdquo) electron will produce twosubevents one from the initial muon and the one from theMichel electron

3 MiniBooNE Cross Section Results

All searches for BSM physics rely on a precise understand-ing of SM interactions However when MiniBooNE began

running there was little neutrino cross section data in the100MeV to fewGeV energy regime In responseMiniBooNEdeveloped a highly successful campaign of cross sectionmeasurements some of which are described here Theseresults are interesting by themselves and also can be used asdirect inputs to the BSM analyses as described later in thispaper

MiniBooNErsquos beam is among the first high-statistics highpurity fluxes in the energy range from 100 to 1500MeVThe observation of the resulting events in a large isotropicdetector with 4120587 coverage is unique Within this detector it isrelatively easy to achieve uniform angular acceptance Alsothe active veto makes it possible to measure NC interactionseffectively Insensitivity of hadronic details worked in pos-itively The hadron multiplicity often causes confusions fortracker detectors Although the MiniBooNE detector cannotmeasure multiple hadron tracks it measures total energyof low energy hadrons (such as protons below Cherenkovthreshold from CCQE interactions) in calorimetric way andas a result the details of final state interactions (FSIs) suchas rescattering absorption and charge exchange do notstrongly affect reconstruction of kinematics

Perhaps most importantly to the overall impact of thedata the MiniBooNE collaboration provided the cross sec-tion data in a form that is most useful to theorists Tradi-tionally cross section data have been presented either as afunction of neutrino energy (119864]) or 4-momentum transfer(1198762) This presentation is problematic in the MiniBooNEenergy region because of the importance of nuclear effectsFermi motion smears the kinematics binding energy shiftsthe energy spectrum nucleon correlations affect both energydependence and normalization of cross sections and pionsmay be created absorbed and charge-exchanged within


the nuclear environmentThese nuclear processesmodify thefeatures of primary neutrino-nucleon interactions and somodel dependent corrections are required to reconstruct 119864]and1198762 This model dependence is problematic because thereare a wide range of models available [11ndash15]

Instead MiniBooNE chose to publish flux-integrateddifferential cross sections in terms of measured kinematicvariables which are essentially model-independent Theseresults have the detector efficiency unfolded but are presentedwithout any other corrections In particular the neutrinoflux is not unfolded The result is data that is neutrinobeam specific and theoretical models are comparable only ifthose models are convoluted with the MiniBooNE predictedneutrino flux However this is trivial for all theorists todo given that MiniBooNE published a first-principles fluxprediction [16] This isolates all model dependence in thedata-to-prediction comparison entirely to the ldquopredictionrdquoside of the discussion The data remains completely generalFor this reason theMiniBooNE cross section data are widelyused to study and compare theoreticalmodels In this sectionwe describe each cross section measurement briefly

31 Charged-Current Quasielastic (CCQE) Scattering TheCCQE interaction is the primary interaction at MiniBooNEenergies This interaction is used to detect ]

120583(]120583) and ]

119890(]119890)

candidate events in the oscillation and Lorentz violationanalyses

]120583+ 119899 997888rarr 120583

minus+ 119901

]120583+ 119901 997888rarr 120583

++ 119899

]119890+ 119899 997888rarr 119890

minus+ 119901

]119890+ 119901 997888rarr 119890

++ 119899

(2)

Therefore a strong understanding of this channel is essentialHigh statistics ]

120583(]120583) interactions are used to study outgoing

lepton kinematics [17] The observable of this channel is theoutgoing muon with no pions in the final state that is thesignal event topology is ldquo1 muon + 0 pion + N protonsrdquoThe main results were published in terms of flux-integrateddouble differential cross sections as functions of the leptonkinetic energy and the scattering angle Figure 3(a) showsthe flux-integrated double differential cross section of ]

120583

CCQE interactions [18]The irreducible background from thepion production channel is subtracted based on a sidebandstudy but the subtracted background is also published so thatreaders can recover the irreducible background

These data have revealed the importance of nucleoncorrelations [19 20] in neutrino scattering which had notbeen taken into account correctly in previous calculationsThis led to models developed using electron scattering datathat were tested against MiniBooNE data [21ndash26] Thesemodels await being tested further by other experiments suchas MINERvA [27 28] and T2K [29]

Another important test is CCQE antineutrino scatteringwhere awide range of expectationswere predicted prior to therun [30ndash34] Before the data could be compared to the results

however the substantial contamination of neutrinos in theantineutrino beam had to be addressed Three independentmethods were used to constrain and tune the neutrinocontamination prediction [35] After subtracting the neutrinocontamination the flux-integrated double differential crosssection for the muon antineutrino CCQE interaction wasmeasured (Figure 3(b)) [36] The comparison of models withdata showed a preference for the high cross section models[37] The rich shape information of the double differentialdata continues to provide additional tests beyond the nor-malization

The main result of the ]120583CCQE cross section mea-

surements is quoted as per CH2molecule This is because

the MiniBooNE target consists of CH2 and the experiment

cannot distinguish antineutrino interactions with boundprotons in the carbon nuclei and free protons from hydrogenAs a separate study however MiniBooNE also presented ananalysis that subtracted the hydrogen interactions where thecross sections were then expressed per bound proton Thishas also provided a useful handle for theorists

32 Charged Single Pion Production The understanding ofcharged-current single-pion channels is of great interestto the nuclear community but also there are significantimplications for the neutrino oscillation studies These inter-actions produce an irreducible background for CCQE events[38ndash41] If the detector fails to tag outgoing pions eitherbecause of detector effects or nuclear effects pion productionchannels may be misclassified as CCQE The distributions ofirreducible backgroundsmust bemodelled and thosemodelsrely on the pion production measurements especially theMiniBooNE data described here Therefore understandingthe kinematic distributions of pion production channels is acrucial task for neutrino oscillation physics

There are three pion production channels for whichMiniBooNE performed dedicated measurements charged-current single 120587+ (CC1120587+) production [8] charged-currentsingle 120587∘ (CC1120587∘) production [9] and neutral current single120587∘ (NC1120587∘) production [42]

]120583+ CH

2997888rarr 120583minus+ 120587++ 119883

]120583+ CH

2997888rarr 120583minus+ 120587∘+ 119883

]120583(]120583) + CH

2+ 997888rarr ]

120583(]120583) + 120587∘+ 119883

(3)

Here the topologies of each event are more complicated andare described as ldquo1 muon + 1 positive pion + N protonsrdquo(CC1120587+) ldquo1 muon + 1 neutral pion +N protonsrdquo (CC1120587∘) andldquo0 muon + 1 neutral pion + N protonsrdquo (NC1120587∘) Althoughthe MiniBooNE detector is not magnetized and thereforecannot distinguish positive and negative pions based ontheir trajectories separation is possible Negative pions areabsorbed by a nucleus almost 100 of the time and inconsequence there is no emission of a Michel electron Thisfact allows MiniBooNE to use the presence of a Michelelectron to select positive pions


02 04 06 08 1 12 14 16 18 2

106

02minus02

minus06minus1

cos 120579120583

T120583 (GeV)

0

5

10

15

20

25

times10minus39

MiniBooNE data (120575NT = 107)

Shape uncertainty

d2120590d

T120583d(c

os 120579 120583

)(c

m2G

eV)

(a)

02 04 06 08 1 12 14 16 18 2

106

02minus02

minus06minus1

cos 120579120583

T120583 (GeV)

0

2

4

6

8

12

10

times10minus39

d2120590d

T120583d(c

os 120579 120583

)(c

m2G

eV)

Shape uncertaintyMiniBooNE 120583 CCQE data (CH2)

(b)

Figure 3 (Color online) MiniBooNE CCQE cross sections (a) shows the muon neutrino flux-integrated CCQE double differential crosssection on a neutron target (b) shows muon antineutrino flux integrated CCQE double differential cross section on a CH

2molecule

times10minus39

012

01

008

006

004

002

0 50 100 150 200 250 300 350 400

MiniBooNE measurementTotal uncertainty

MC prediction

Pion kinetic energy (MeV)

120597120590120597(K

E 120587)

(cm

2M

eV)

(a)

times10minus39

35

30

25

20

15

10

5

00 02 04 06 08 1 12 14

Systematic errorStatistical error MC prediction

p120587∘ (GeVc)

120597120590120597p120587∘(

120583N

rarr120583minus120587∘ N

998400 )(c

m2G

eVc

CH2)

(b)

Figure 4 (Color online)MiniBooNE single pion production results (a) is120587+ kinetic energy differential cross section fromCC1120587+ interactionon CH

2[8] (b) is 120587∘ momentum differential cross section from CC1120587∘ interaction in CH

2[9] As you see predictions underestimate data for

both channels and the shapes do not agree as well

Because of themore complicated topologies the differen-tial cross sections for these data sets are presented in variousvariables Among them distributions in pion kinetic energyand momentum distributions exhibit the presence of nucleareffects while we do not see this from the lepton distributionsFigure 4 shows differential cross sections CC1120587+ pion kineticenergy and CC1120587∘ pion momentum respectively The shapeand normalization are sensitive to nuclear effects such aspion absorption charge exchange and rescattering There-fore the state-of-the-art nuclearmodels [43 44] can be testedby these MiniBooNE data

33 Neutral Current Elastic (NCE) Scattering TheNCE inter-action can take place on both neutrons and protons for bothneutrino and antineutrinos The results are relevant for darkmatter searches in two ways first through the measurementofΔ119904 that we describe here second as a background to a directdark matter search by MiniBooNE described in Section 6

]120583(]120583) + 119901 997888rarr ]

120583(]120583) + 119901

]120583(]120583) + 119899 997888rarr ]

120583(]120583) + 119899

(4)


1800

1600

1400

1200

1000

800

600

400

200

0100 200 300 400 500 600

Reconstructed nucleon energy (MeV)

p rarr p (MC)n rarr n (MC)

Even

ts24

MeV

(a)

times10minus39

2

15

1

05

002 04 06 08 1 12 14 16

MC NCE-like background

MC (MA = 102GeV)MC (MA = 135GeV)

d120590d

Q2 Q

E(c

m2G

eV2)

Q2QE (GeV2)

MiniBooNE NCE cross section with total error

(b)

Figure 5 (Color online)MiniBooNENCE results [45] (a) shows simulated kinetic energy of protons and neutrons fromNCE inMiniBooNEThe line denotes the Cherenkov threshold that is only protons which have higher energy from this line emit Cherenkov radiation (b) showsthe antineutrino NCE differential cross section As you see the data shows a ldquoroll-overrdquo in the low 119876

2 region

Since only protons with kinetic energy above sim350MeVproduce Cherenkov radiation (Figure 5(a)) the majority ofthese events only produce scintillation light and thereforenecessitate a strictly calorimetric analysis For neutrons thereis no Cherenkov radiation and the chance the secondaryproton from the primary neutron exceeds this thresholdis extremely low (in other words if the proton exceedsCherenkov threshold this will most likely form the primaryneutrino NC interaction) We call this topology ldquo0 muon +0 pion + N protonsrdquo However when the kinetic energyexceeded the Cherenkov threshold it is also possible toobserve the direction of nucleons [10]

The calorimetric measurement causes the signal to beinsensitive to the detailed final state interaction (FSI) processAlso similar to the antineutrino CCQE analysis (Section 31)scattering on C and H cannot be distinguished so thetarget may be a bound proton a free proton or a boundneutron Hence the cross section is presented per CH

2target

Figure 5(b) shows the antineutrino mode NCE differentialcross section [45]

The NCE data allows us to refine our understanding ofnuclear effects at low 119876

2 In NCE the observable is the sumof all kinetic energies of outgoing protons sum119879

119873 Using this

the 1198762 can be reconstructed by assuming the target nucleonat rest

1198762

119876119864= 2119872

119873sum119879119873 (5)

Note that irreducible backgrounds such as NC pion produc-tion without an outgoing pion are subtracted to make 1198762

119876119864

physical

The reconstructed data shows a roll-over at the low 1198762

region due to the combination of Pauli blocking and thenuclear shadowing Pauli blocking is a phenomenon wherelow momentum transfer interactions are forbidden due tooccupied phase space and the nuclear shadowing happenswhen the resolution (= low momentum transfer interaction)is insufficient to resolve a single nucleon wave function Notethat these nuclear effects do not appear if the signal of NCEis defined to be a single isolated proton where strong FSImigrates all nucleons to low energy region [46] Howeverbecause the MiniBooNE NCE data presents the sum of thetotal nucleon kinetic energy the results preserve the featureof the primary neutrino interaction physics

NCE interactions are connected to direct dark mattersearches through the measurement of Δ119904 the spin of thestrange quarks in the nucleon It has been shown [47]that the uncertainty of Δ119904 on the spin-dependent scatteringbetween dark matter particles and target nuclei can be a largesystematic errorTherefore aΔ119904measurement is another waythat neutrino cross section measurements contribute to BSMphysics We briefly consider how this information can beextracted from the NCE data here

The spin structure of a nucleon is deeply fundamentaland quite complicated In the naive constituent quark modelthe spin minus12 of a nucleon can be derived by adding valencequark spins where in the static limit (1198762 rarr 0) there are threevalence quarks that make up all static properties of a nucleonsuch as charge magnetic moment and spin However thespin contribution from up and down quarks deduced frominclusive deep inelastic scattering (DIS) measurements [48ndash50] indicates in the static limit that up and down quarkssupport only sim10 of the total spin of a protonThis so-called


ldquospin crisisrdquo has triggered a world wide effort to look forother sources of spin in a nucleon One of the interestingadditional spin contributions is from the strange quarkscalled Δ119904 Although recent measurements show the staticlimits of the strange quark charge andmagnetic contributionsare consistent with zero [51] the nonzero value of Δ119904 isstill under debate [52] because the weak coupling (prop (1 minus

4sin2120579119908)) of Δ119904 with parity violating electron asymmetry

does not allow a clear measurement of Δ119904 through electronscattering experiments

HoweverΔ119904 also contributes to neutrino NCE scatteringas an axial vector isoscalar term increasing the cross sectionfor neutrino-protonNCE and decreasing the cross section forneutrino-neutron NCE Figure 6 shows the ratio of ]119901 rarr

]119901 to ]119873 rarr ]119873 candidates events together with severalpredictions with nonzero Δ119904 Note MiniBooNE can onlyisolate neutrino-proton NCE in the case of high energyprotons and the denominator is chosen to be the total NCEevents in order to cancel systematics The fit to find Δ119904 isperformed on this plot After the fit the best fit value ofΔ119904 = 008 plusmn 026 is found Unfortunately MiniBooNE doesnot have enough sensitivity to definitively determine nonzeroΔ119904 This is due to the poor experimental proton-neutronseparation which is only possible at high energy with largesystematics Therefore a detector which has the ability toidentify low energy protons such as MicroBooNE [53] willhave better sensitivity to Δ119904

4 MiniBooNE Oscillation Results

The most well-known BSM search performed by the Mini-BooNE experiment was for neutrino oscillations consistentwith LSND These are also the most thoroughly reviewedresults Here we briefly describe the studies We recommend[54] for a more extended discussion

MiniBooNE was conceived in 1998 shortly after theLSND results had reached 38120590 significance and before thethree massive neutrino model for active-flavor oscillations(]SM) had been well established However it was clear thatif LSND was observing an oscillation signal the associatedsquared mass splitting (Δ1198982large) was more than an orderof magnitude larger than other evidence for oscillations Inthis circumstance a complicated three-neutrino appearanceprobability can reduce to amore simple two-neutrino case fordesigns with (127119871119864) asymp 1Δ1198982large such as MiniBooNE

This approach assumes no 119862119875 violation in the mix-ing matrix and hence equal probabilities of neutrino andantineutrino oscillations Leptonic119862119875 violation in themixingmatrix had been discussed by Wolfenstein in 1978 [55] as anatural analogy to the quark sector However by extensionof that analogy the assumption was that this effect if itexisted would be very small As a result theoretical interestin 1998 was largely isolated to 119862119875 violation In retrospectthis approach was naive but this made sense as the guidingprinciple for theMiniBooNE design at the timeThe goal wasto test a simple two-neutrino oscillation model with equalprobabilities of neutrinos and antineutrinos on the basisthat this would be a good approximation if the underlying

05

04

03

02

01

350 400 450 500 550 600 650 700 750

(prarr

p)(N

rarrN

)on

CH

2

Data with total error

T (MeV)

MC Δs = minus05 MA = 135GeVMC Δs = 00 MA = 135GeVMC Δs = 05 MA = 135GeV

Figure 6 (Color online) The ratio of ]119901 rarr ]119901 to ]119873 rarr ]119873 as afunction of the reconstructed total kinetic energy of nucleons [10]

reality was BSM physics If a signal was not observed thesignificantly different systematic errors were expected toresult in a clear exclusion of the result Thus the MiniBooNEexperiment began running in neutrino mode which pro-vided roughly sim6 times higher rate than antineutrino modea necessary choice since theMiniBooNE experiment was alsorelied on a significant Booster performance improvementThe results showed an anomalous excess of electron-likeevents in the ]

120583dominant neutrino mode beam [56] that

was similar to but not in good agreement with LSND Theexperiment then switched to running in antineutrino modewhere a result in agreement with LSND was observed

Rather than considering these events historically wepresent both results together in the next section followed by adiscussion of interpretations and considerations of follow-upexperiments There is a world-wide effort to probe the sterileneutrino in the region Δ1198982 sim 1 eV2 [57] It is desirable forMiniBooNE to confirm this excess is electron-like which isconsidered the sterile neutrino oscillation signal not back-ground gamma rays associated with ]

120583(]120583)NC interactions

The MicroBooNE experiment [53] was proposed along thisline The MicroBooNE experiment features a large liquidargon (LAr) time projection chamber (TPC) and it has anability to distinguish an electron (positron) and a gamma rayThe MicroBooNE experiment will start data taking in 2014We will discuss more in a later section

41 The Neutrino and Antineutrino Appearance OscillationResults After a decade of data collection MiniBooNErsquosfinal appearance oscillation results have been published[58] Figure 7 shows the electron candidate (]

120583rarr ]

119890

oscillation candidate) distribution in neutrino mode andpositron (]

120583rarr ]

119890oscillation candidate) distribution in

antineutrino mode Note that since the MiniBooNE detectoris not magnetized in general it cannot distinguish between


12

10

08

06

04

02

02 04 06 08 10 12 14 15 30

Antineutrino

Data (stat err)e from 120583+minus

e from K+minus

e from K0

120587∘ misid

DirtOther

Δ rarr N120574

Constr syst error

Even

tsM

eV

EQE (GeV)

25

20

15

10

05

00

Neutrino

02 04 06 08 10 12 14 15 30


e from K+minus

e from K0

120587∘ misid

DirtOther

Δ rarr N120574

Constr syst error

Even

tsM

eV

EQE (GeV)

(a)

Antineutrino

102

10

1

10minus1

10minus3 10minus2 10minus1 1

LSND 90 CLLSND 99 CLKARMEN2 90 CL6890

9599

Δm

2(e

V2)

sin2 2120579

Neutrino

10

1

10minus1

10minus2


LSND 90 CLLSND 99 CL

6890

9599

ICARUS 90 CL

Δm

2(e

V2)

sin2 2120579

(b)

Figure 7 (Color online)The finalMiniBooNE oscillation results [58] (a) shows the reconstructed neutrino energy distribution of oscillationcandidate events The top is for antineutrino mode and the bottom is for neutrino mode (b) shows the allowed region in Δ1198982minussin22120579 wherethe best fit points are shown in black stars

electrons and positrons and so both are grouped into theldquoelectron-likerdquo category

MiniBooNE observed event excesses in both modes ofrunning but the results have slight qualitative differenceIn neutrino mode (left bottom plot) there is a statisticallysignificant (38120590) event excess in the low energy regionAlthough the excess is significant the shape of the spectrumleaves some tension with the oscillation hypothesis fromLSND which you can see from the right bottom plot wherethe MiniBooNE best fit region does not overlap well withthe LSND best fit region MiniBooNE uses a likelihood-ratiotechnique [59] to find the best fit values (Δ1198982 sin22120579) =

(314 eV2 0002) in neutrino mode with 1205942dof of 13268

In antineutrino mode (left top plot) the observed excess isnot as statistically strong as neutrino mode (28120590) This is

expected when one compares the protons on target in eachmode and considers the lower antineutrino flux and crosssection Although the statistical significance is lower shapeagreement with the LSND hypothesis is better Again this canbe seen from the right top plot where the parameter spaceselected by the MiniBooNE data agrees with the LSND bestfit regionThe best fit point in thismode was (005 eV2 0842)with 1205942dof of 4869

The combined result significance is dominated by neu-trino mode and is 38120590 It is possible to find compatibleregions in a simple two-neutrino model between the twodata sets [58] However we emphasize that consideringMiniBooNE oscillations in the absence of other oscillationexperiments leads to misunderstandings We consider thispoint in a later section


411 PotentialNonoscillation Explanations Thebackground-only 120594

2-probability for the MiniBooNE oscillation searchwas 16 and 05 relative to the best oscillation fits forneutrino and antineutrino mode respectively Neverthelessit is important to explore in detail the potential SM explana-tions of the MiniBooNE results In particular a Cherenkovdetector such as MiniBooNE lacks the ability to distinguishelectrons from single photons Therefore any single photonproduction mechanism via neutral current interactions is alikely suspect as a background to this search

The primary source of single photons is the NC1120587∘reaction followed by 120587∘ rarr 120574120574 where one photon is lostbecause it exits the detector or because the relativistic boostcauses the energy to be too low to allow the Cherenkovsignal to be identified At the low energies ofMiniBooNE thebackground from two 120587∘ rings that merge is less importantthan the case where a photon is lost FortunatelyMiniBooNEhas the largest sample of well reconstructed NC120587∘ eventsever obtained Keeping in mind that the largest uncertaintiesare in the production and not in the kinematics of thephotons themselves MiniBooNE was able to use this largedata set to carefully evaluate this appearance background[60] This study can constrain the variation of this largestmisID background (red histogram in Figure 7(a)) and wehave shown that if NC120587∘ was the source of the MiniBooNEexcess MiniBooNErsquos systematic error on the productionwould have to be underestimated by an order of magnitude[56] This is not a likely solution to the problem and so weturn to single photon production

MiniBooNE also included the NC single photon processin their simulation The process involves the single photondecay of a neutral current Δ resonance which has a smallbut nonnegligible branching ratio (lt1 of NC1120587∘) The rateof this process is strongly tied to the resonant production ofpions therefore MiniBooNE can utilize their in situ NC1120587∘measurement to constrain this background Therefore thevariation of this second biggest misID background (lightbrown histograms in Figure 7(a)) is also constrained by theNC1120587∘measurement andwe found this process was not largeenough to explain the MiniBooNE excess [56]

After the first MiniBooNE oscillation result in 2007 [7]it was pointed out that there were additional single-photon-production channels missing from the NUANCE [11] eventsimulation used by experiments such as MiniBooNE [61]Figure 8 shows the relevant underlying diagramThis sourcetriangular anomaly mediated photon production featuresweak coupling via the neutrino neutral current and strongcoupling with nucleons or nuclei In fact a similar typeof interaction was suggested originally in the 1980s [62]however it was not widely noted or further investigatedThistype of process can generate a single gamma ray from a NCinteraction The strength of the anomaly mediated diagramwas evaluated [63] and the event rate in MiniBooNE afterconvoluting the BNB neutrino flux was at the time esti-mated to be high enough to explain a part of the MiniBooNEexcesses [64]

The initially high estimate which may have explainedthe MiniBooNE result led nuclear theorists to reevaluate

NN

Z

120574

120596

Figure 8The triangular anomalymediated photon productionTheneutrino neutral current couples via Z-boson and the target nucleonor nucleus couples with a strong force mediated vector meson suchas an omega meson

this exotic ldquo119885 minus 120574 minus 120596 couplingrdquo properly including nucleareffects such as Pauli blocking and Δ resonance media widthmodification as well as including careful calibrations ofnuclear parameters from external data [65ndash67] These areimportant to include since nuclear effects are sizable in thisenergy region Note these nuclear effects tend to reduce thecross section

Figure 9 shows our current knowledge of this channel[68] The figure shows the total cross section of NC singlephoton production process per 12C nucleus whichmeans thecross section includes all potential processes contributing tothis final state topology (ldquo0 muon + 0 pion + 1 photon + Nprotonsrdquo) both incoherently (neutrino-nucleon interaction)and coherently (neutrino-nucleus interaction) As you seeall neutrino interaction generators used by experimentalists(GENIE [13] NEUT [14] and NUANCE [11]) tend to predictlower cross sections than state-of-the-art theoretical modelsby Wang et al [65] Zhang and Serot [69] and Hill [64]

The NC single photon prediction may explain part of theexcess but it is not likely to explain all of it [69 70] Therewas an active discussion on this channel at the recent INTworkshop and further experimental data on NC single pho-ton production can help to guide more theoretical work [71]

Meanwhile a BSM NC single photon model was pro-posed [72] where a decay of a heavy neutrino produces asingle photon signal in the detector Figure 10 shows theconcept of such a model The heavy neutrino is produced bythemixing with amuon neutrino then the decay of the heavyneutrino leaves a photon signal in the detector Interestinglythe required mass range of the heavy neutrino to producesuch a signal in the MiniBooNE detector (40MeV lt 119898

ℎlt

80MeV) is not constrained by other experimentsThe beautyof this model is that it also explains the LSND signal whileevading the KARMEN null oscillation result [73]

At this time NOMAD is the only experiment to haveperformed a dedicated NC single photon search [74] TheNOMAD result was consistent with its background predic-tion thus NOMAD set a limit on this channel Howeverthe limit was quoted with NOMADrsquos average energy (lt 119864 gt

sim17GeV) and is therefore not as relevant for lower energyexperiments such asMiniBooNETherefore it is essential for


0018

0016

0014

0012

001

0008

0006

0004

0002

00 05 1 15 2 25 3

E (GeV)

GENIENEUTNUANCE

Wang et alZhang and SerotHill

120590(10minus

38cm

212C)

Figure 9 (Color online) A comparison of the total cross section ofNC photon production per 12C nucleus [68] The neutrino interac-tion generators used by experimentalists (GENIE [13] NEUT [14]and NUANCE [11]) tend to predict lower cross sections than state-of-the-art theoreticalmodels (Wang et al [65] Zhang and Serot [69]Hill [64])

N N

Z

120574

120583 120583

h

Figure 10The concept of a heavy neutrino decay signal in theMini-BooNE detector [73] The mixing of a neutrino with a hypotheticalheavy neutrino and its short life time allows for it to decay in theMiniBooNE detector to leave a photon signal

new experiments that seek to check theMiniBooNE results tohave an ability to distinguish between electrons and photonssuch as MicroBooNE [53]

412 Potential Oscillation Explanations Numerous articleshave been written on the potential of oscillation models toexplain the MiniBooNE signal In particular we recommend[75] as a pedagogical discussion of the issues of fitting thedata We excerpt the results from this reference here

When MiniBooNE and LSND results are consideredwithin the context of the worldrsquos oscillation data ]SM isexcluded because a third mass splitting must be introducedBecause the 119885 rarr ]] results from LEP and SLD [1]limit the number of low mass active neutrinos to threesterile neutrinos are introduced to allow for these data setsSterile neutrinos are a consequence of many theories andcould evade limits from cosmology as discussed in [57]

(note recent Planck results [76] leave some tension with thisinterpretation)

If one sterile neutrino is added to the three activeneutrinos then the model is termed (3 + 1) Two additionalsterile neutrinos lead to a (3 + 2) model and three resultin a (3 + 3) model The mass states are mixtures of flavorstates and in these models fits to the data yield mass statesthat are either mostly active flavors or mostly sterile flavorsThe splitting between the mostly active and mostly sterileflavors is large and the splittings between the active flavorsare comparatively negligible So in sterile neutrino fits theshort-baseline approximation where the mostly active flavorsare regarded as degenerate in mass is used In such a model3 + 1 models are simply two-neutrino models such as whatwas initially proposed to explain LSND

The disagreement between the MiniBooNE neutrino andantineutrino data leads to very poor fits for 3 + 1 modelsIn order to introduce a difference in the neutrino oscillationprobabilities 119862119875 violation must be included in the modelFor the term which multiplies the 119862119875-parameter to besignificant there must be two mass splittings that are withinless than two orders of magnitude of each other This can beaccommodated in a 3 + 2 model

Since the MiniBooNE and LSND results were publishedtwo new anomalies consistent with high Δ119898

2 oscillationswere brought forward These are the reactor anomaly [77]which has been interpreted as ]

119890rarr ]119904 and the gallium

source anomaly [78] which can be interpreted as ]119890rarr ]119904

[57] Both anomalies have weaker significance than Mini-BooNEandLSND but they can be combined into a consistentmodel

With this said many experiments have searched foroscillations in the high Δ119898

2 region and found no evidenceof oscillations Reference [75] describes nine such resultsThe exclusion limits for electron-flavor disappearance andelectron-flavor appearance can be shown to be compatiblewith the results of the four anomalous measurements How-ever when muon-flavor disappearance is included there istension between the data sets which leads to low compatibil-ity except in the 3 + 3 picture (or more elaborated version of3 + 2 model called ldquo1 + 3 + 1rdquo model [79])

413 Near-Future Experiment Addressing the MiniBooNEResults To test MiniBooNE signals in a model-independentway a new experiment is planned on the BNB The Micro-BooNE experiment is a large liquid argon time projectionchamber (LArTPC) experiment [53] at Fermilab planning tostart data taking from 2014 It is part of the US LArTPC pro-gram [80] with the eventual goal of an ultra-large LArTPCexperiment such as LBNE [81] The experiments are moti-vated by the ldquobubble chamber levelrdquo LArTPC imaging quality

Figure 11 shows a drawing [53] of MicroBooNErsquos 170 tonfoam-insulated cryostat The TPC volume is 89 tons Ionizedelectrons along the neutrino-induced charged particle tracksare drifted via a high electric field in the TPC volume tothe anode wires The node wires are configured on threeplanes alternating by 60∘ orientation to allow 3-dimensionalreconstruction of the tracks The first 2 wire planes record


HD foamsaddles

end-cap

18998400998400 sprayed foaminsulation

Drift

Weldedremovable

Figure 11 (Color online) A drawing of MicroBooNE cryostat [53]The 170 ton cryostat contains the 89 ton TPC

the signal from the induction on wires and the last planerecords the actual collection of ionization electrons

An array of 8-inch PMTs is equipped behind the wireplanes [82] The main purpose of this photon collectionsystem is to reject out-of-time cosmic rays and to triggeron in-time signals since the scintillation light from theinteraction arrives in simns whereas the time scale of ionizationelectron drift is of order simms The detection of scintillationphotons from LAr is not straightforward First of all thewavelength of Ar scintillation light is 128 nm which requirescareful RampD on potential wavelength shifters for use in LAr[83ndash85] Second the PMTs themselves behave differently in acryogenic environment as compared to a warm environmentleading to the need for careful characterization [86]

The purity of the liquid argon must be kept very highto allow electrons to drift a long distance Electronegativeimpurities (eg water and oxygen molecules) are removedthrough a custommade filter to achieve le ppb level impurity[87 88] Such filtering is also effective for removing nitrogenmolecules which do not affect electron drift but do attenuatescintillation light [89]

A high resolution LArTPC detector will be a powerfultool in understanding the MiniBooNE signal because thedetector is expected to have the excellent electron-photonseparation Energetic electrons and photons both produce anelectromagnetic shower in a LArTPC However the initial119889119864119889119909 of a single photon will be twice higher than in thesingle electron case in the first few centimeters before thetrack develops into the shower Due to their high reso-lution capabilities LArTPC detectors can distinguish thisdifference Moreover a displaced vertex in the case of aphoton conversion can be distinguished from a track thatis continuous from the vertex indicative of an electronThe combination of these details can provide high efficiencybackground rejection for MicroBooNE

5 Test of Lorentz and CPT Violation

Lorentz and CPT violation are scenarios motivated fromPlanck scale theories such as string theory [90] In the effec-tive field theory framework Lorentz violation contributes

additional terms to the vacuum Lagrangian of neutrinos andhence modifies neutrino oscillations [91 92] Since Lorentzviolating fields are of fixed direction in the universe ifLorentz invariance is broken the rotation of the Earth causesa sidereal time dependence of neutrino oscillation signalsThere are number of phenomenological neutrino oscillationmodels based on Lorentz and CPT violation [93ndash95] someof which can explain the LSND excess [96] In fact a siderealtime dependence analysis of LSND data [97] failed to rejectthe Lorentz violation scenarioTherefore it might be possibleto reconcile LSND and MiniBooNE oscillation signals underLorentz violation

51 Analysis Although Lorentz violation can be studied inany frame or coordinate system it is convenient to chooseone coordinate system to compare data sets The standardchoice is the Sun-centered celestial equatorial coordinates[98] where the origin of the coordinate is the center of theSun The orbital plane of the Earth is tilted so that the orbitalaxis and the rotation axis of the Earth align This directiondefineS the 119885-axis The 119883-axis points vernal equinox andthe 119884-axis is chosen to complete the right handed systemBecause the time scale of the rotation of the galaxy is too longfor any terrestrial experiments the Sun-centered frame is thebetter choice to test rotation symmetry (by using the rotationof the Earth) and Lorentz boost (by using the revolution ofthe Earth)

Having defined the coordinates one uses the standard-model extension (SME) [99ndash101] as the framework for ageneral search for Lorentz violationThe SME can be consid-ered a minimum extension of the SM including the particleLorentz and CPT violation For the neutrino sector the SMELagrangian can be written as [91]

L =1

2119894120595119860Γ120583

119860119861

harr

119863120583120595119861minus 120595119860119872119860119861120595119861+ ℎ119888 (6)

Γ]119860119861

= 120574]120575119860119861

+ 119888120583]119860119861120574120583+ 119889120583]1198601198611205745120574120583+ 119890

]119860119861

+ 119894119891]1198601198611205745+1

2119892120582120583]119860119861

120590120582120583

(7)

119872119860119861

= 119898119860119861

+ 1198941198985119860119861

1205745+ 119886120583

119860119861120574120583+ 119887120583

119860119861+1

2119867120583]119860119861120590120583] (8)

Here the 119860119861 subscripts represent the flavor basis Thefirst term of (7) and the first and second terms of (8) are theonly nonzero terms in the SM and the rest of the terms arefrom Lorentz violation

The physics consequences predicted by Lorentz violationare very rich Among them we are interested in Lorentz vio-lating neutrino oscillations Neutrino oscillations are naturalinterferometers and they are sensitive to small effects such asLorentz violationThe smoking gun of Lorentz violation is thesidereal time dependence of physics observables Thereforewe used the Lorentz violating ]

120583rarr ]119890(]120583rarr ]119890) neutrino

oscillation formula derived from above Lagrangian [102] tofit the sidereal time distribution of the ]

120583rarr ]119890(]120583rarr ]119890)

oscillation candidate data Here potentially any day-nighteffect either from the beamor from the detector couldmimic


8070605040302010

0 10000 20000 30000 40000 50000 60000 70000 80000

-os

c can

dida

te ev

ents

Sidereal time (s)

Data

Background

Flat solutionPOT corrected data 3-parameter fit

5-parameter fit

(a)

-os

c can

dida

te ev

ents 40

3530252015

5

0 10000 20000 30000 40000 50000 60000 70000 80000

Sidereal time (s)

Data

Background

Flat solutionPOT corrected data

10

3-parameter fit5-parameter fit

(b)

Figure 12 The MiniBooNE Lorentz violation results [103] (a) shows the neutrino mode electron-like low energy excess sidereal timedistribution and (b) shows the antineutrino mode sidereal time distribution Here the data with a POT correction (open circle) show thesize of the beam day-night variation There are three fit curves based on different assumptions a flat solution (dotted) a three-parameter fit(solid curve) and a full five-parameter fit (dash-dotted curve)

the sidereal time distribution MiniBooNE studied effectsversus the time distribution of the delivered POT and thehigh statistics ]

120583(]120583) CCQE sample [18 36] and confirmed

that day-night effects on both ]119890and ]119890oscillation candidates

are well below statistical errors

52 Results Figure 12 shows the neutrino and antineutrinomode electron-like events as a function of sidereal time [103]Since background events are time-independent we fit curveson the flat time-independent background (dashed lines)There are three curves fit to the data depending on differenthypotheses A flat solution (dotted lines) assumes only time-independent Lorentz violating term a 3-parameter fit (solidlines) includes all CPT-odd Lorentz violating terms and a5-parameter fit (dash-dotted lines) is the full parameter fitincluding both CPT-odd and CPT-even Lorentz violatingterms Although the antineutrino mode electron-like eventsshow a rather interesting sidereal time dependence the sta-tistical significance is still low Therefore MiniBooNE foundthat the data are consistent with no Lorentz violation Thisanalysis provided the first limits on five time independentSME coefficients at the level of 10minus20 GeV (CPT-odd) andorder 10minus20 (CPT-even) Further analysis inferred limits oneach SME coefficient and together with limits from theMINOS near detector [104 105] it turns out these limitsleave tension to reconcile theMiniBooNE andLSNDdata setsunder a simple Lorentz violation motivated scenario [4]

In fact existing limits from MiniBooNE [103] MINOS[104ndash107] IceCube [108] and Double Chooz [109 110] setvery tight limits on possible Lorentz violation in the neutrinosector at the terrestrial level This was one of the reasonswhy the superluminal neutrino signal from OPERA [111]was suspicious from the beginning Such a signal wouldhave required very large Lorentz violation while avoidingall these constraints when writing down the theory Strictlyspeaking limits on Lorentz violation from the oscillationexperiments cannot be applied directly to the neutrino timeof flight (TOF) measurement [112] However introducing

1100

1000

900

800

700

600

500

40060 80 100 120 140 160 180 200 220 240

E (MeV)

Even

ts

Data with all errorsTotal MC

Preliminary

Best fit (M120594 = 150MeV 120581 = 00024)

Figure 13 (Color online)The dark matter fit result to the NCE data[116]

Protonbeam

(Near)detectorp + p(n) rarr Vlowast rarr 120594120594

120587∘ 120578 rarr V120574 rarr 120594120594120574120594 + N rarr 120594 + N

120587+ rarr 120583+120583120594 + e rarr

120594 + e

120583+ rarr e+e120583

Figure 14 (Color online) The concept of the dark matter beam inMiniBooNE [116] The dominant production mode of dark matterparticles is decays of the mediator particles created by decays ofneutral mesonsThe dark matter particles can be also made throughthe direct collisions of protons on the beam dump

large Lorentz violation in the neutrino TOF without otherlarge parameters such as those associated with oscillationsseems unnatural


10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary

mV = 300MeV POT = 175 times 1020

Direct detectionElectronmuon g-2Monojet (CDF)

MiniBooNERelic densityBaBar

N120594 rarr N120594 120572998400 = 01

ΔmZ and EW fit

(a)


10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary



e120594 rarr e120594 120572998400 = 01

ΔmZ and EW fit

(b)

Figure 15 (color online) The MiniBooNE dark matter particles search phase space [116] Here the 119909-axis is the dark matter mass 119898120594 and

the 119910-axis is either the dark matter-nucleon or dark matter-electron cross section assuming the vector mediator mass and the gauge coupling(119898119881= 300MeV and 120572 = 01) The MiniBooNE exclusion region can be seen in green

6 Dark Matter Search

The proton collisions on target in the BNB line that producea large flux of neutrinos could potentially produce sub-GeVscale darkmatter particles thatmimicNCE interactions in theMiniBooNE detector [113ndash115]Themost interesting scenariois that this light dark matter particle is the dark matter ofthe universe which requires a light vector mediator particle(called a ldquodark photonrdquo) in the model in order to obtain anefficient annihilation cross section The minimum extensionof the SM with the light dark matter particle and the vectormediator can be written in the following way [114]

L = L119878119872

minus1

41198812

120583] +1

21198982

1198811198812

120583+ 120581119881]120597120583119865

120583]

+1003816100381610038161003816100381611986312058312059410038161003816100381610038161003816

2

minus 1198982

120594

10038161003816100381610038161205941003816100381610038161003816

2

+ sdot sdot sdot

(9)

The model has four free parameters the mass of the lightdark matter 119898

120594 the mass of the vector mediator 119898

119881 kinetic

mixing of the vector mediator and the photon 120581 and thevectormediatorrsquos gauge coupling 1198901015840 (or1205721015840 = 119890101584024120587) Nonzero120581 leads to the decay of neutral mesons to a photon and a darkphoton and the dark photon in turn can decay to darkmatterparticles This would be the dominant process to producedarkmatter particles in the BNBThe second process is direct

production from the parton level annihilation by protonscolliding in the target

61 MiniBooNE Searches for Dark Matter Particles Mini-BooNE tested this model with the existing antineutrino NCEdata set taken during the oscillation studies Figure 13 showsthe fit result with a light dark matter particles hypothesis[116] The plot shows the total energy distribution of theantineutrino NCE sample and the red and blue histogramsshow before and after the fit The best fit values are 119872

120594=

150MeV and 120581 = 00024 As can be seen the currentsensitivity to the light dark matter model is low

The antineutrino mode data set is used because it hasa lower neutrino interaction rate than the neutrino modebeam Nevertheless due to the antineutrino backgroundsonly weak limits are obtained on the kinetic mixing parame-ter 120581

This motivated a tuning of the proton beam that allowedMiniBooNE to run in a mode in which the protons aredirected onto the beam dump instead of the target eliminat-ing the DIF neutrino flux Figure 14 shows the schematic ofthis measurement [116] The beam-dump mode is achievedby tuning the sim1mm beam to aim 09 cm gap between theberyllium target rod and the inner conductor of the hornto hit the beam dump located at the end of decay pipe


POT = 175 times 1020 POT = 175 times 1020

01 1

Electronmuon g-2Monojet (CDF)


e120594 rarr e120594N120594 rarr N120594

10minus1

10minus2

10minus3

10minus4

mV (GeV)

Preliminary Preliminary

m120594 = 10MeV m120594 = 10MeV

J120595 rarr invisible LSND

K+ rarr 120587++ invisible

01 1



10minus1

10minus2

10minus3

10minus4

mV (GeV)



120572998400 = 01120572998400 = 01

120581120581

ΔmZ and EW fitΔmZ and EW fit

Figure 16 (Color online)TheMiniBooNE dark matter search phase space [116] Here 119909-axis is the vector mediator mass119898119881 and the 119910-axis

is the kinetic mixing parameter 120581 assuming the dark matter mass and the gauge coupling (119898120594= 10MeV and 120572 = 01) MiniBooNE exclusion

region can be seen in green

(50m from the target) directly This reduces the neutrinobackground by roughly a factor of 67 Darkmatter productionis largely unaffected in this run mode since it occurs throughneutral meson decay MiniBooNE is now running in thisconfiguration The goal is to accumulate 175 times 10

20 POTdata before MicroBooNE starts beam data taking in theneutrino mode not the beam-dump mode

62 Parameter Space of Light DarkMatter Particles and VectorMediators Figure 15 shows the two-dimensional phase spaceof dark matter-nucleon and dark matter-electron scatteringcross sections versus dark matter mass 119898

120594[116] The limits

from direct searches end up at the right side (119898120594sim1 GeV)

and the left-side light dark matter region is explored byother techniques such as rare decays and collider physicsMiniBooNE addresses direct light dark matter searches Inthe case of either interaction MiniBooNE is sensitive to thedark matter mass in the 10 to 200MeV mass region

There are many reasons why such a light dark mattersearch is interesting First recent data [117ndash120] from thedirect WIMP (weakly interacting massive particle) searchessuggest possible signals of dark matter particles in the lightermass region For example SuperCDMS is also aiming the lowmass dark matter search by utilizing the ionization signals[121] Second the muon g-2 anomaly can be explained bythe presence of a vector mediator [122 123] Although theinteresting phase space of muon g-2 was already excluded by

other experiments MiniBooNE can further push the limitsin this region

The sensitivity that is obtained from the dark matter-electron scattering looks weaker than dark matter-nucleon inthe 120590 minus 119898

120594phase space (Figure 15(b)) however as Figure 16

shows the limit from the dark matter-electron interactioncan be stronger in the low vectormass region in 120581 minus 119898

119881phase

space [116] Therefore both channels are complimentary andMiniBooNE should strive to measure both There was a littleinterest in ]-119890 elastic scattering because of its small crosssection but this electron channel is as important as thenucleon channel for the dark matter search

63 Dark Matter Time of Flight (TOF) MiniBooNErsquos sensi-tivity to dark matter particles can be further improved bycombining event topology and kinematics with the timinginformation Figure 17 shows the ldquodarkmatter TOFrdquo conceptThe dark matter particles are most likely produced at thebeam dump after prompt decays of neutral pions or etas(lt 10minus16 sec) so the dark matter production is localized inboth time and spaceThis would result in a dark matter beamthat has a well-defined timing and allows us to perform theTOF-based searchesTheheavier darkmatter particles shouldbe slower than the neutrinos (as well as the speed of light)Thus the dark matter particles would lag behind the bunchcenter and separate from the neutrino background


WIMP time of flight

50m dump

50m decay pipe

Resistive wall monitor (RMS)

8GeVprotons

Coax cable delivers RMS timing signal to detector where it is recorded

490m = 1633 ns at c

WIMPs can travel slower than c

Figure 17 (Color online)The concept of dark matter particles TOF Because of the localization of the dark matter particle production in timeand in space the dark matter beam has well-defined timing structure

In the Fermilab Booster the 81 bunches have 19 ns separa-tions (Section 21) MiniBooNE defines events within 4 ns lt119879 lt 16 ns from the bunch center as the in-time events andthe 119879 lt 4 ns and 119879 gt 16 ns events are out-time The absolutetiming information of all bunches is recorded by the resistivewall monitor (RWM) which is located just before the targetUsing the previous MiniBooNE antineutrino run to test thisidea Figure 18 shows the overlaid profile of all bunches ofantineutrino NCE candidate events [116] As expected thedata shows the peak in in-time region because the data isdominated by antineutrino NCE interactions

A beam-dump test run was performed for one weekduring 2012 running During the beam-dumpmode test runthe timing of neutrinoswas tested usingCC interaction SincetheCC interaction is detected through the promptCherenkovlight from the muons timing resolution is better thanNCE events Using the new system installed for the beam-dump run MiniBooNE achieved 15 ns resolution [116] Theresolution will be worse for NCE because of the nature of theexponential decay of scintillation light butMiniBooNE nev-ertheless still expects sim4 ns resolutions This gives full confi-dence for MiniBooNE to perform a full beam-dump run

7 Conclusion

Since beginning its run in 2002 MiniBooNE has beensearching for new physics in a wide variety of waysThemostimportant results have been those related to oscillations ofsterile neutrinos which has pushed the community towardnew and exciting experiments in the future [53 57 124ndash126]MiniBooNE also tested for possible signals from the Planckscales and set very strong constraints on Lorentz violationMiniBooNErsquos light dark matter search with a beam-dumpconfiguration run is a unique opportunity that can providethe best limit on the dark matter mass in the 10 to 200MeVrange All of these searches have been grounded in therevolutionary set of cross section measurements performedwith MiniBooNE This experiment demonstrates the richpossibilities to go beyond the standard model in low costshort-baseline venues and encourages a strong investment infuture programs

1800

1600

1400

1200

1000

800

600

400

200

00 2 4 6 8 10 12 14 16 18 20

Preliminary

Bunch time (ns)

Data (minus strobe and dirt)with stat errorTotal MC (correct WS)NC signal

BkgDirtStrobe

Even

ts

Figure 18 (Color online)The reconstructed NCE event time profilefor the antineutrino mode beam The events are overlaid relative tothe bunch center As expected the data peaks in the bunch centerwhich means these are dominated with antineutrino interactionsand there is no delay of events

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

Janet Conrad thanks the National Science Foundation forsupport through NSF-PHY-1205175The authors thank BrianBatell for inputs about light dark matter physics also theythank Joshua Spitz for careful reading of the paper andvaluable comments

References

[1] J Beringer J-F Arguin R M Barnett et al ldquoReview of particlephysicsrdquo Physical Review D vol 86 Article ID 010001 2012


[2] K Abe J Adam H Aihara et al ldquoObservation of electronneutrino appearance in a muon neutrino beamrdquo PhysicalReview Letters vol 112 no 6 Article ID 061802 8 pages 2014

[3] A Aguilar-Arevalo L B Auerbach R L Burman et alldquoEvidence for neutrino oscillations from the observation ofelectron anti-neutrinos in amuon anti-neutrino beamrdquoPhysicalReview D vol 64 Article ID 112007 2001

[4] T Katori ldquoTests of Lorentz and CPT violation withMiniBooNEneutrino oscillation excessesrdquoModern Physics Letters A vol 27no 25 Article ID 1230024 2012

[5] A Aguilar-Arevalo C E Anderson A O Bazarko et alldquoNeutrino flux prediction at MiniBooNErdquo Physical Review Dvol 79 Article ID 072002 2009

[6] A Aguilar-Arevalo C E Andersonp L M Bartoszekg et alldquoThe MiniBooNE detectorrdquo Nuclear Instruments and Methodsin Physics Research Section A vol 599 pp 28ndash46 2009

[7] A Aguilar-Arevalo A O Bazarko S J Brice et al ldquoSearch forelectronneutrino appearance at the9987791198982 sim 1 eV2 scalerdquoPhysicalReview Letters vol 98 Article ID 231801 2007

[8] A A Aguilar-Arevalo C E Anderson A O Bazarko et alldquoMeasurement of neutrino-induced charged-current chargedpion production cross sections on mineral oil at 119864] sim 1GeVrdquoPhysical Review D vol 83 no 5 Article ID 052007 2011

[9] A Aguilar-Arevalo C E Anderson A O Bazarko et alldquoMeasurement of ^

120583-induced charged-current neutral pion

production cross sections on mineral oil at Ev isin 05 minus 20 GeVrdquoPhysical Review D vol 83 Article ID 052009 2011

[10] A Aguilar-Arevalo B G Tice [MiniBooNE collaboration]et al ldquoMeasurement of the neutrino neutral-current elasticdifferential cross section on mineral oil at 119864V sim 1GeVrdquo PhysicalReview D vol 82 Article ID 092005 2010

[11] D Casper ldquoThe nuance neutrino simulation and the futurerdquoNuclear Physics B vol 112 no 1ndash3 pp 161ndash170 2002

[12] C Juszczak ldquoRunning nuwrordquo Acta Physica Polonica B vol 40pp 2507ndash2512 2009

[13] C Andreopoulos A Bell D Bhattacharya et al ldquoThe GENIEneutrino Monte Carlo generatorrdquo Nuclear Instruments andMethods in Physics Research Section A vol 614 pp 87ndash104 2010

[14] Y Hayato ldquoA neutrino interaction simulation program libraryNEUTrdquo Acta Physica Polonica B vol 40 pp 2477ndash2489 2009

[15] O Buss T Gaitanos K Gallmeister et al ldquoTransport-theoretical description of nuclear reactionsrdquo Physics Reportsvol 512 no 1-2 pp 1ndash124 2012

[16] C Juszczak J T Sobczyk and J Zmuda ldquoExtraction of theaxial mass parameter from MiniBooNE neutrino quasielasticdouble differential cross-section datardquo Physical Review C vol82 Article ID 045502 2010

[17] A Aguilar-Arevalo A O Bazarko S J Brice et al ldquoMea-surement of muon neutrino quasielastic scattering on carbonrdquoPhysical Review Letters vol 100 Article ID 032301 2008

[18] A Aguilar-Arevalo C E Anderson A O Bazarko et alldquoFirst measurement of the muon neutrino charged currentquasielastic double differential cross sectionrdquo Physical ReviewD vol 81 no 9 Article ID 092005 22 pages 2010

[19] MMartini M Ericson G Chanfray and J Marteau ldquoA unifiedapproach for nucleon knock-out coherent and incoherentpion production in neutrino interactions with nucleirdquo PhysicalReview C vol 80 Article ID 065501 2009

[20] J Nieves I R Simo andMVVacas ldquoInclusive charged-currentneutrino-nucleus reactionsrdquo Physical Review C vol 83 no 4Article ID 045501 2011

[21] M Martini M Ericson and G Chanfray ldquoNeutrino quasielas-tic interaction and nuclear dynamicsrdquo Physical Review C vol84 no 5 Article ID 055502 2011

[22] J Nieves I R Simo and M V Vacas ldquoThe nucleon axial massand the MiniBooNE quasielastic neutrinondashnucleus scatteringproblemrdquo Physics Letters B vol 707 no 1 pp 72ndash75 2012

[23] J Amaro M Barbaro J Caballero T Donnelly and CWilliamson ldquoMeson-exchange currents and quasielastic neu-trino cross sections in the superscaling approximation modelrdquoPhysics Letters B vol 696 pp 151ndash155 2011

[24] A Bodek H Budd and M Christy ldquoNeutrino quasielasticscattering on nuclear targetsrdquoThe European Physical Journal Cvol 71 article 1726 2011

[25] A Meucci C Giusti and F D Pacati ldquoRelativistic descriptionsof final-state interactions in neutral-current neutrino-nucleusscattering at MiniBooNE kinematicscrdquo Physical Review D vol84 Article ID 113003 2011

[26] O Lalakulich K Gallmeister and U Mosel ldquoComplete setof polarization transfer observables for the 16O(rarr

119901 rarr119901)16F

reaction at 296 MeV and 0rdquo Physical Review C vol 84 no 1Article ID 014614 8 pages 2012

[27] G Fiorentini D W Schmitz and P A Rodrigues ldquoMeasure-ment of muon neutrino quasielastic scattering on a hydrocar-bon target at 119864V sim 35GeVrdquo Physical Review Letters vol 111Article ID 022502 2013

[28] L Fields J Chvojka L Aliaga et al ldquoMeasurement of muonantineutrino Quasi-elastic scattering on a hydrocarbon targetat E ] sim 35 GeVrdquo Physical Review Letters vol 111 Article ID022501 2013

[29] K Abe N Abgrall H Aihara et al ldquoMeasurement of theinclusive ]

120583charged current cross section on carbon in the near

detector of the T2K experimentrdquo Physical Review D vol 87Article ID 092003 2013

[30] MMartini M Ericson G Chanfray and J Marteau ldquoNeutrinoand antineutrino quasielastic interactions with nucleirdquo PhysicalReview C vol 81 Article ID 045502 2010

[31] M Martini and M Ericson ldquoQuasielastic and multinu-cleon excitations in antineutrino-nucleus interactionsrdquo PhysicalReview C vol 87 no 6 Article ID 065501 2013

[32] J Nieves I Ruiz Simo andMVicenteVacas ldquoTwoparticle-holeexcitations in charged current quasielastic antineutrino-nucleusscatteringrdquo Physics Letters B vol 721 pp 90ndash93 2013

[33] A Meucci and C Giusti ldquoRelativistic descriptions of final-state interactions in charged-current quasielastic antineutrino-nucleus scattering at MiniBooNE kinematicsrdquo Physical ReviewD vol 85 Article ID 093002 2010

[34] J Amaro M Barbaro J Caballero and T Donnelly ldquoMeson-exchange currents and quasielastic antineutrino cross sectionsin the superscaling approximationrdquo Physical Review Letters vol108 Article ID 152501 2012

[35] A A Aguilar-Arevalo C E Anderson S J Brice et alldquoMeasurement of the neutrino component of an antineutrinobeam observed by a nonmagnetized detectorrdquo Physical ReviewD vol 84 no 7 Article ID 072005 2011

[36] A Aguilar-Arevalo B C Brown L Bugel et al ldquoFirst measure-ment of the muon antineutrino double-differential charged-current quasielastic cross sectionrdquo Physical Review D vol 88Article ID 032001 2013

[37] J Grange and R Dharmapalan ldquoNew anti-neutrino cross-section results from MiniBooNErdquo httparxivorgabs13047395


[38] M Martini M Ericson and G Chanfray ldquoNeutrino energyreconstruction problems and neutrino oscillationsrdquo PhysicalReview D vol 85 Article ID 093012 2012

[39] D Meloni and M Martini ldquoRevisiting the T2K data using dif-ferent models for the neutrino-nucleus cross sectionsrdquo PhysicsLetters B vol 716 no 1 pp 186ndash192 2012

[40] J Nieves F Sanchez I Ruiz Simo and M Vicente VacasldquoNeutrino energy reconstruction and the shape of the CCQE-like total cross sectionrdquo Physical Review D vol 85 Article ID113008 2012

[41] O Lalakulich U Mosel and K Gallmeister ldquoNeutrino energyreconstruction in quasielastic-like scattering in theMiniBooNEand T2K experimentsrdquo Physical Review C vol 86 Article ID054606 2012

[42] A A Aguilar-Arevalo C E Anderson A O Bazarko et alldquoMeasurement of ]

120583and ]

120583induced neutral current single 1205870

production cross sections on mineral oil at 119864] sim O (1 GeV)rdquoPhysical Review D vol 81 Article ID 013005 2010

[43] O Lalakulich and U Mosel ldquoPion production in the Mini-BooNE experimentrdquo Physical Review C vol 87 no 1 Article ID014602 2013

[44] E Hernndez J Nieves and M J V Vacas ldquoSingle pionproduction in neutrino nucleus scatteringrdquo Physical Review Dvol 87 Article ID 113009 2013

[45] A Aguilar-Arevalo B C Brown L Bugel et al ldquoMeasurementof the antineutrino neutral-current elastic differential crosssectionrdquo httparxivorgabsarXiv13097257

[46] T Leitner L Alvarez-Ruso and U Mosel ldquoNeutral currentneutrino-nucleus interactions at intermediate energiesrdquo Phys-ical Review C vol 74 Article ID 065502 2006

[47] J R Ellis K A Olive and C Savage ldquoHadronic uncertaintiesin the elastic scattering of supersymmetric darkmatterrdquoPhysicalReview D vol 77 Article ID 065026 2008

[48] J Ashmana B Badelekb G Baum et al ldquoAmeasurement of thespin asymmetry and determination of the structure function 119892

1

in deep inelastic muon-proton scatteringrdquo Physics Letters B vol206 no 2 pp 364ndash370 1988

[49] D Adams B Adeva E Arik et al ldquoMeasurement of the spin-dependent structure function 119892

1(119909) of the protonrdquo Physics

Letters B vol 329 pp 399ndash406 1994[50] V W Hughes V Papavassiliou R Piegaia K P Schuler and G

Baum ldquoThe integral of the spin-dependent structure functiong1p and the Ellis-Jaffe sum rulerdquo Physics Letters B vol 212 no4 pp 511ndash514 1988

[51] D Androic D S Armstrong J Arvieux et al ldquoStrange quarkcontributions to parity-violating asymmetries in the backwardangle G0 electron scattering experimentrdquo Physical Review Let-ters vol 104 Article ID 012001 2010

[52] S F Pate D W McKee and V Papavassiliou ldquoStrange quarkcontribution to the vector and axial form factors of thenucleon combined analysis of data from the G0 HAPPExand Brookhaven E734 experimentsrdquo Physical Review C vol 78Article ID 015207 2008

[53] L Camilleri ldquoMicroBooNErdquo Nuclear Physics BmdashProceedingsSupplements vol 237-238 pp 181ndash183 2013

[54] J M Conrad W C Louis and M H Shaevitz ldquoThe LSND andMiniBooNE oscillation searches at high Δm2rdquo Annual Reviewof Nuclear and Particle Science vol 63 pp 45ndash67 2013

[55] L Wolfenstein ldquoOscillations among three neutrino types andCP violationrdquo Physical Review D vol 18 no 3 pp 958ndash9601978

[56] A Aguilar-Arevalo B C Brown L Bugel et al ldquoUnexplainedexcess of electronlike events from a 1-GeV neutrino beamrdquoPhysical Review Letters vol 102 Article ID 101802 2009

[57] KNAbazajianMAAcero S KAgarwalla et al ldquoLight sterileneutrinos a white paperrdquo httparxivorgabs12045379

[58] A Aguilar-Arevalo B C Brown L Bugel et al ldquoImprovedsearch for ]

120583rarr ]119890oscillations in theMiniBooNE experimentrdquo

Physical Review Letters vol 110 no 16 Article ID 161801 2013[59] A Aguilar-Arevalo C Anderson S Brice et al ldquoEvent excess

in the MiniBooNE search for V120583rarr V119890oscillationsrdquo Physical

Review Letters vol 105 Article ID 181801 2010[60] A Aguilar-Arevalo C E Anderson A O Bazarko et al ldquoFirst

observation of coherent 1205870 production in neutrinondashnucleusinteractions with 119864] lt 2GeVrdquo Physics Letters B vol 664 pp 41ndash46 2008

[61] J A Harvey C T Hill and R J Hill ldquoAnomaly mediatedneutrino-photon interactions at finite baryon densityrdquo PhysicalReview Letters vol 99 Article ID 261601 2007

[62] S Gershtein Y Y Komachenko and M Y A KhlopovldquoProduction of single photons in the exclusive neutrino processV119873 rarr V120574119873rdquo Soviet Journal of Nuclear Physics vol 33 p 8601981

[63] R J Hill ldquoLow energy analysis of V119873 rarr V119873120574in the standard

modelrdquo Physical Review D vol 81 Article ID 013008 2010[64] R J Hill ldquoSingle photon background to V

119890appearance at

MiniBooNErdquo Physical ReviewD vol 84 Article ID 017501 2011[65] E Wang L Alvarez-Ruso and J Nieves ldquoPhoton emission in

neutral-current interactions at intermediate energiesrdquo PhysicalReview C vol 89 Article ID 015503 2014

[66] X Zhang and B D Serot ldquoCoherent neutrinoproduction ofphotons and pions in a chiral effective field theory for nucleirdquoPhysical Review C vol 86 Article ID 035504 2012

[67] X Zhang and B D Serot ldquoIncoherent neutrinoproduction ofphotons and pions in a chiral effective field theory for nucleirdquoPhysical Review C vol 86 Article ID 035502 2012

[68] R Dharmapalan I Stancu Z Djurcic et al ldquoA Proposal forMiniBooNE+ a new investigation ofmuon neutrino to electronneutrino oscillations with improved sensitivity in an enhancedMiniBooNE experimentrdquo FERMILAB-PROPOSAL-1033 2013

[69] X Zhang and B D Serot ldquoCan neutrino-induced photonproduction explain the low energy excess in MiniBooNErdquoPhysics Letters B vol 719 pp 409ndash414 2013

[70] E Wang L Alvarez-Ruso and J Nieves ldquoSingle photon eventsfrom neutral current interactions at MiniBooNErdquo httparxivorgabs14076060

[71] ldquoNeutrino-Nucleus Interactions for Current and Next Gener-ation Neutrino Oscillation Experimentsrdquo 2013 httpwwwintwashingtoneduPROGRAMS13-54w

[72] S Gninenko ldquoMiniBooNE anomaly and heavy neutrino decayrdquoPhysical Review Letters vol 103 Article ID 241802 2009

[73] S N Gninenko ldquoResolution of puzzles from the LSND KAR-MEN andMiniBooNE experimentsrdquoPhysical ReviewD vol 83Article ID 015015 2011

[74] C Kullenberg G Bassompierre J M Gaillard et al ldquoA Searchfor Single Photon Events in Neutrino Interactionsrdquo PhysicsLetters B vol 706 pp 268ndash275 2012

[75] J Conrad C Ignarra G Karagiorgi M Shaevitz and J SpitzldquoSterile neutrino fits to short-baseline neutrino oscillationmeasurementsrdquo Advances in High Energy Physics vol 2013Article ID 163897 26 pages 2013


[76] P Ade N Aghanim C Armitage-Caplan et al ldquoPlanck 2013results XVI Cosmological parametersrdquo 2013 httparxivorgabs13035076

[77] G Mention M Fechner T Lasserre et al ldquoThe reactorantineutrino anomalyrdquo Physical Review D vol 83 Article ID073006 2011

[78] C Giunti andM Laveder ldquoStatistical significance of the galliumanomalyrdquo Physical Review C vol 83 Article ID 065504 2011

[79] J Kopp P A N Machado M Maltoni and T Schwetz ldquoSterileneutrino oscillations the global picturerdquo Journal of High EnergyPhysics vol 50 2013

[80] G Karagiorgi ldquoCurrent and future liquid argon neutrino exper-imentrdquo httparxivorgabs13042083

[81] C Adams D Adams T Akiri et al ldquoThe long-baseline neu-trino experiment exploring fundamental symmetries of theuniverserdquo 2013 httparxivorgabs13077335

[82] T Katori ldquoMicroBooNE light collection systemrdquo Journal ofInstrumentation vol 8 Article ID C10011 2013

[83] B Baptista L Bugel C Chiu J Conrad andC Ignarra ldquoBench-marking TPB-coated light guides for liquid argon TPC lightdetection systemsrdquo 2012 httparxivorgabs12103793

[84] C Chiu C Ignarra L Bugel et al ldquoEnvironmental efectson TPBwavelength-shifting coatingsrdquo httparxivorgabs12045762

[85] B Jones J Van Gemert J Conrad and A Pla-Dalmau ldquoPho-todegradation mechanisms of tetraphenyl butadiene coatingsfor liquid argon detectorsrdquo Journal of Instrumentation vol 8Article ID P01013 2013

[86] T Briese L Bugel J Conrad et al ldquoTesting of cryogenic pho-tomultiplier tubes for the MicroBooNE experimentrdquo Journal ofInstrumentation vol 8 Article ID T07005 2013

[87] A Curioni B Fleming W Jaskierny et al ldquoA regenerable filterfor liquid argon purificationrdquoNuclear Instruments andMethodsin Physics Research A vol 605 pp 306ndash311 2009

[88] R Andrews W Jaskierny H Jostlein C Kendziora and SPordes ldquoA system to test the effects of materials on the electrondrift lifetime in liquid argon and observations on the effect ofwaterrdquo Nuclear Instruments and Methods in Physics Research Avol 608 pp 251ndash258 2009

[89] B Baptista L Bugel C Chiu et al ldquoBenchmarking TPB-coatedlight guides for liquid argon TPC light detection systemsrdquohttparxivorgabsarXiv12103793

[90] V A Kostelecky and S Samuel ldquoSpontaneous breaking ofLorentz symmetry in string theoryrdquo Physical Review D vol 39article 683 1989

[91] V A Kostelecky and M Mewes ldquoLorentz and CPT violation inneutrinosrdquo Physical Review D vol 69 no 1 Article ID 01600525 pages 2004

[92] J SDiaz VAKostelecky andMMewes ldquoPerturbative Lorentzand CPT violation for neutrino and antineutrino oscillationsrdquoPhysical Review D vol 80 Article ID 076007 2009

[93] V A Kostelecky and M Mewes ldquoLorentz and CPT violationin the neutrino sectorrdquo Physical Review D vol 70 Article ID031902(R) 2004

[94] J S Diaz and V A Kostelecky ldquoThree-parameter Lorentz-violating texture for neutrino mixingrdquo Physics Letters B vol700 no 1 pp 25ndash28 2011

[95] J S Dıaz and A Kostelecky ldquoLorentz- and CPT-violatingmodels for neutrino oscillationsrdquo Physical Review D vol 85 no1 Article ID 016013 17 pages 2012

[96] T Katori V A Kostelecky and R Tayloe ldquoGlobal three-param-eter model for neutrino oscillations using Lorentz violationrdquoPhysical Review D vol 74 Article ID 105009 2006

[97] L Auerbach R L Burman D O Caldwell et al ldquoTests ofLorentz violation in V

120583rarr V119890oscillationsrdquo Physical Review D

vol 72 Article ID 0506067 2005[98] V A Kostelecky and N Russell ldquoData tables for Lorentz and

CPT violationrdquo Reviews of Modern Physics vol 83 no 1 pp 11ndash31 2011

[99] D Colladay and V A Kostelecky ldquoLorentz-violating extensionof the standard modelrdquo Physical Review D vol 58 Article ID9809521 1998

[100] D Colladay and V A Kostelecky ldquoCPT violation and thestandard modelrdquo Physical Review D vol 55 pp 6760ndash67741997

[101] V A Kostelecky ldquoGravity Lorentz violation and the standardmodelrdquo Physical Review D vol 69 no 10 Article ID 1050092004

[102] V A Kostelecky and M Mewes ldquoLorentz violation and short-baseline neutrino experimentsrdquo Physical Review D vol 70Article ID 076002 2004

[103] A Aguilar-Arevalo C E Anderson A O Bazarko et al ldquoTestof Lorentz and CPT violation with short baseline neutrinooscillation excessesrdquoPhysics Letters B vol 718 no 4-5 pp 1303ndash1308 2013

[104] P Adamson C Andreopoulos K E Arms et al ldquoTestingLorentz invariance andCPT conservationwithNuMIneutrinosin the MINOS near detectorrdquo Physical Review Letters vol 101no 15 Article ID 151601 2008

[105] P Adamson D S Ayres G Barr et al ldquoSearch for Lorentzinvariance and CPT violation with muon antineutrinos in theMINOS near detectorrdquo Physical Review D vol 85 Article ID031101 2012

[106] P Adamson D J Auty and D S Ayres ldquoSearch for Lorentzinvariance and CPT violation with the MINOS far detectorrdquoPhysical Review Letters vol 105 no 15 Article ID 151601 2010

[107] B Rebel and SMufson ldquoThe search for neutrinomdashantineutrinomixing resulting from Lorentz invariance violation using neu-trino interactions in MINOSrdquo Astroparticle Physics vol 48 pp78ndash81 2013

[108] R Abbasi Y Abdou and T Abu-Zayyad ldquoSearch for a Lorentz-violating sidereal signal with atmospheric neutrinos in Ice-Cuberdquo Physical Review D vol 82 Article ID 112003 2010

[109] Y Abe C Aberle J C dos Anjos et al ldquoFirst test of Lorentzviolation with a reactor-based antineutrino experimentrdquo Physi-cal Review D vol 86 Article ID 112009 2012

[110] J Dıaz T Katori J Spitz and J Conrad ldquoSearch for neutrino-antineutrino oscillations with a reactor experimentrdquo PhysicsLetters B vol 727 no 4-5 pp 412ndash416 2013

[111] T Adam N Agafonova A Aleksandrov et al ldquoMeasurementof the neutrino velocity with the OPERA detector in the CNGSbeamrdquo Journal of High Energy Physics vol 1210 article 093 2012

[112] A Kostelecky and M Mewes ldquoNeutrinos with Lorentz-violating operators of arbitrary dimensionrdquo Physical Review Dvol 85 Article ID 096005 2012

[113] B Batell M Pospelov and A Ritz ldquoExploring portals to ahidden sector through fixed targetsrdquo Physical Review D vol 80Article ID 095024 2009

[114] P de Niverville M Pospelov and A Ritz ldquoObserving a lightdark matter beam with neutrino experimentsrdquo Physical ReviewD vol 84 Article ID 075020 2011


[115] P deNiverville DMcKeen andA Ritz ldquoSignatures of sub-GeVdarkmatter beams at neutrino experimentsrdquo Physical ReviewDvol 86 Article ID 035022 2012

[116] R Dharmapalan I Stancu R A Johnson et al ldquoA proposalto search for dark matter with MiniBooNErdquo Fermilab Proposal1032 2012

[117] R Bernabei P Belli F Cappella et al ldquoNew results fromDAMALIBRArdquo The European Physical Journal C vol 67 no1-2 pp 39ndash49 2010

[118] C Aalseth P S Barbeau N S Bowden et al ldquoResults from asearch for light-mass dark matter with a P-type point contactgermaniumdetectorrdquo Physical Review Letters vol 106 ArticleID 131301 2011

[119] G Angloher M Bauer I Bavykina et al ldquoResults from 730kg days of the CRESST-II dark matter searchrdquo The EuropeanPhysical Journal C vol 72 p 1971 2012

[120] R Agnese Z Ahmed A J Anderson et al ldquoSilicon detectordark matter results from the final exposure of CDMS IIrdquoPhysical Review Letters vol 111 Article ID 251301 2013

[121] R Agnese A J Anderson M Asai et al ldquoSearch for low-mass weakly interactingmassive particles using voltage-assistedcalorimetric ionization detection in the SuperCDMS experi-mentrdquo Physical Review Letters vol 112 no 4 Article ID 0413022014

[122] G Bennett B Bousquet H N Brown et al ldquoFinal report ofthe E821 muon anomalous magnetic moment measurement atBNLrdquo Physical Review D vol 73 Article ID 072003 2006

[123] M Pospelov ldquoSecluded U(1) below the weak scalerdquo PhysicalReview D vol 80 Article ID 095002 2009

[124] A Adelmann J R Alonso W Barletta et al ldquoCost-effectivedesign options for IsoDARrdquo 2012 httparxivorgabs12104454

[125] DAdey S K Agarwalla CMAnkenbrandt et al ldquonuSTORM-neutrinos from STORedmuons proposal to the fermilab PACrdquo2013 httparxivorgabs13086822

[126] Y-F Li J Cao Y Wang and L Zhan ldquoUnambiguous determi-nation of the neutrino mass hierarchy using reactor neutrinosrdquoPhysical Review D vol 88 Article ID 013008 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

High Energy PhysicsAdvances in

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014


FluidsJournal of

Atomic and Molecular Physics

Journal of



Advances in Condensed Matter Physics

OpticsInternational Journal of



AstronomyAdvances in

International Journal of


Superconductivity


Statistical MechanicsInternational Journal of


GravityJournal of


AstrophysicsJournal of


Physics Research International


Solid State PhysicsJournal of

Computational Methods in Physics

Journal of



Soft MatterJournal of

Hindawi Publishing Corporationhttpwwwhindawicom

AerodynamicsJournal of

Volume 2014


PhotonicsJournal of


Journal of

Biophysics


ThermodynamicsJournal of


Booster Targethall

TevatronMain injector

(a) (b)

BoosterTarget

andhorn Decay

region Earth Detector

Primary beam Secondary beam Tertiary beam

(protons) (mesons) (neutrinos)

120587

120583

(c)

Figure 1 The MiniBooNE experiment layout [4] (a) The Fermilab accelerator complex (b) The MiniBooNE detector with inset showingthe black inner volume and the white outer volume (c) Schematic layout of the beam and detector [18]

Here 120579 and Δ1198982 are oscillation parameters to control the

amplitude and the period respectively (further discussed inSection 4) 119871 is the distance from neutrino production tointeraction in meters and 119864 is the energy of the neutrino inMeV

An experiment which maintains the same 119871119864 ratioshould observe an oscillation probability consistent withLSND if the simple two neutrino model is a good approx-imation of the underlying effect However by employingan average 119864 which is an order of magnitude larger thanLSND the systematic errors associated with production anddecay are quite different If 119871 is increased accordingly and nosignal is observed this rules out the two-neutrino oscillationhypothesis of the LSND result

MiniBooNE was designed with this in mind The Mini-BooNE beam peaked at sim700MeV and the Cherenkovdetector was located at sim500m baseline Figure 1 shows anoverview of theMiniBooNE design [4] and in the remainderof this section we provide more details

21 Booster Neutrino Beam-Line The Booster NeutrinoBeam-line (BNB) extracts 8 GeV kinetic energy protonsfrom the Fermilab Booster a 149m diameter synchrotron(Figure 1(a)) Eighty-one bunches separated in time bysim 19 ns are extracted by a fast kicker within a sim16 120583s pulseEach pulse contains around 4 times 10

12 protons Typically fourto five pulses per second were sent to BNB to produce theneutrino beam

This high intensity proton pulse collides with a berylliumtarget to produce a shower of mesons (Figure 1(c))The targetis located within a magnetic focusing horn For neutrino

mode running the toroidal field generated by the hornfocuses on positive mesons with 120587+ decay-in-flight (DIF) asthe primary source of the ]

120583beam In antineutrino mode

running the horn focuses on negative mesons to create the]120583dominant beam The details of the BNB neutrino flux

prediction can be found in [5]MiniBooNE collected 646 times 10

20 proton-on-target(POT) in neutrino mode and 1127 times 1020 POT in antineu-trino mode

22 The MiniBooNE Detector The MiniBooNE detectorlocated 541m away from the target is a mineral-oil-basedCherenkov detector The 122m spherical tank filled withpure mineral oil (CH

2)119899 has two optically separated regions

The interior region lined by 1280 8-inch photomultipliertubes (PMTs) contains the target volume An outer volumeequipped with 240 8-inch PMTs serves as the veto region [6]The presence of a charged particle above threshold is detectedthrough the Cherenkov radiation observed by PMTs As seenfromFigure 1(b) the inner volume is painted black to preventscattering of the Cherenkov light improving the reconstruc-tion precisionOn the other hand the outer volume is paintedwhite to enhance scattering of Cherenkov light in order toachieve the 999 rejection of cosmic rays by the veto [7]even with fairly sparse PMT coverage The charge and timeinformation from all PMTs is used to reconstruct kinematicsof charged-lepton and electromagnetic events MiniBooNEmineral oil produces a small amount of scintillation lightwhich can be used to reconstruct the total energy of theinteraction via calorimetry which is particularly importantfor particles below Cherenkov threshold



Neutral pion

NC120587∘

Muon

Electron

120583 CCQE

e CCQE

+ N rarr + N + 120587∘

120583 + n rarr p + 120583minus
















120583(]120583) and ]

119890(]119890)


]120583+ 119899 997888rarr 120583

minus+ 119901

]120583+ 119901 997888rarr 120583

++ 119899

]119890+ 119899 997888rarr 119890

minus+ 119901

]119890+ 119901 997888rarr 119890

++ 119899

(2)




120583











]120583+ CH

2997888rarr 120583minus+ 120587++ 119883

]120583+ CH

2997888rarr 120583minus+ 120587∘+ 119883

]120583(]120583) + CH

2+ 997888rarr ]

120583(]120583) + 120587∘+ 119883

(3)



02 04 06 08 1 12 14 16 18 2

106

02minus02

minus06minus1

cos 120579120583

T120583 (GeV)

0

5

10

15

20

25

times10minus39


Shape uncertainty

d2120590d

T120583d(c

os 120579 120583

)(c

m2G

eV)

(a)

02 04 06 08 1 12 14 16 18 2

106

02minus02

minus06minus1

cos 120579120583

T120583 (GeV)

0

2

4

6

8

12

10

times10minus39

d2120590d

T120583d(c

os 120579 120583

)(c

m2G

eV)


(b)


2molecule

times10minus39

012

01

008

006

004

002

0 50 100 150 200 250 300 350 400


MC prediction


120597120590120597(K

E 120587)

(cm

2M

eV)

(a)

times10minus39

35

30

25

20

15

10

5

00 02 04 06 08 1 12 14


p120587∘ (GeVc)

120597120590120597p120587∘(

120583N


998400 )(c

m2G

eVc

CH2)

(b)







]120583(]120583) + 119901 997888rarr ]

120583(]120583) + 119901

]120583(]120583) + 119899 997888rarr ]

120583(]120583) + 119899

(4)


1800

1600

1400

1200

1000

800

600

400

200

0100 200 300 400 500 600



Even

ts24

MeV

(a)

times10minus39

2

15

1

05

002 04 06 08 1 12 14 16



d120590d

Q2 Q

E(c

m2G

eV2)

Q2QE (GeV2)


(b)


2 region



2target




119873 Using this


1198762

119876119864= 2119872

119873sum119879119873 (5)


119876119864

physical















05

04

03

02

01

350 400 450 500 550 600 650 700 750

(prarr

p)(N

rarrN

)on

CH

2


T (MeV)










120583rarr ]

119890


120583rarr ]




12

10

08

06

04

02

02 04 06 08 10 12 14 15 30

Antineutrino


e from K+minus

e from K0

120587∘ misid

DirtOther

Δ rarr N120574

Constr syst error

Even

tsM

eV

EQE (GeV)

25

20

15

10

05

00

Neutrino

02 04 06 08 10 12 14 15 30


e from K+minus

e from K0

120587∘ misid

DirtOther

Δ rarr N120574

Constr syst error

Even

tsM

eV

EQE (GeV)

(a)

Antineutrino

102

10

1

10minus1



9599

Δm

2(e

V2)

sin2 2120579

Neutrino

10

1

10minus1

10minus2



6890

9599

ICARUS 90 CL

Δm

2(e

V2)

sin2 2120579

(b)















NN

Z

120574

120596






ℎlt





0018

0016

0014

0012

001

0008

0006

0004

0002

00 05 1 15 2 25 3

E (GeV)

GENIENEUTNUANCE


120590(10minus

38cm

212C)


N N

Z

120574

120583 120583

h


















HD foamsaddles

end-cap


Drift

Weldedremovable











L =1

2119894120595119860Γ120583

119860119861

harr

119863120583120595119861minus 120595119860119872119860119861120595119861+ ℎ119888 (6)

Γ]119860119861

= 120574]120575119860119861

+ 119888120583]119860119861120574120583+ 119889120583]1198601198611205745120574120583+ 119890

]119860119861

+ 119894119891]1198601198611205745+1

2119892120582120583]119860119861

120590120582120583

(7)

119872119860119861

= 119898119860119861

+ 1198941198985119860119861

1205745+ 119886120583

119860119861120574120583+ 119887120583

119860119861+1

2119867120583]119860119861120590120583] (8)





120583rarr ]119890(]120583rarr ]119890)



8070605040302010

0 10000 20000 30000 40000 50000 60000 70000 80000

-os

c can

dida

te ev

ents

Sidereal time (s)

Data

Background


5-parameter fit

(a)

-os

c can

dida

te ev

ents 40

3530252015

5

0 10000 20000 30000 40000 50000 60000 70000 80000

Sidereal time (s)

Data

Background


10


(b)








1100

1000

900

800

700

600

500

40060 80 100 120 140 160 180 200 220 240

E (MeV)

Even

ts


Preliminary

Best fit (M120594 = 150MeV 120581 = 00024)


Protonbeam



120587+ rarr 120583+120583120594 + e rarr

120594 + e

120583+ rarr e+e120583




10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary




N120594 rarr N120594 120572998400 = 01

ΔmZ and EW fit

(a)


10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary



e120594 rarr e120594 120572998400 = 01

ΔmZ and EW fit

(b)





L = L119878119872

minus1

41198812

120583] +1

21198982

1198811198812

120583+ 120581119881]120597120583119865

120583]

+1003816100381610038161003816100381611986312058312059410038161003816100381610038161003816

2

minus 1198982

120594

10038161003816100381610038161205941003816100381610038161003816

2

+ sdot sdot sdot

(9)



119881 kinetic




120594=






01 1



e120594 rarr e120594N120594 rarr N120594

10minus1

10minus2

10minus3

10minus4

mV (GeV)


m120594 = 10MeV m120594 = 10MeV



01 1



10minus1

10minus2

10minus3

10minus4

mV (GeV)



120572998400 = 01120572998400 = 01

120581120581
















119881phase




WIMP time of flight

50m dump

50m decay pipe


8GeVprotons


490m = 1633 ns at c





7 Conclusion


1800

1600

1400

1200

1000

800

600

400

200

00 2 4 6 8 10 12 14 16 18 20

Preliminary

Bunch time (ns)


BkgDirtStrobe

Even

ts




Acknowledgments


References






























119901 rarr119901)16F





















120583and ]









1























119890appearance at









































































FluidsJournal of


Journal of










Superconductivity




GravityJournal of








Journal of






Volume 2014


PhotonicsJournal of


Journal of

Biophysics





Neutral pion

NC120587∘

Muon

Electron

120583 CCQE

e CCQE

+ N rarr + N + 120587∘

120583 + n rarr p + 120583minus
















120583(]120583) and ]

119890(]119890)


]120583+ 119899 997888rarr 120583

minus+ 119901

]120583+ 119901 997888rarr 120583

++ 119899

]119890+ 119899 997888rarr 119890

minus+ 119901

]119890+ 119901 997888rarr 119890

++ 119899

(2)




120583











]120583+ CH

2997888rarr 120583minus+ 120587++ 119883

]120583+ CH

2997888rarr 120583minus+ 120587∘+ 119883

]120583(]120583) + CH

2+ 997888rarr ]

120583(]120583) + 120587∘+ 119883

(3)



02 04 06 08 1 12 14 16 18 2

106

02minus02

minus06minus1

cos 120579120583

T120583 (GeV)

0

5

10

15

20

25

times10minus39


Shape uncertainty

d2120590d

T120583d(c

os 120579 120583

)(c

m2G

eV)

(a)

02 04 06 08 1 12 14 16 18 2

106

02minus02

minus06minus1

cos 120579120583

T120583 (GeV)

0

2

4

6

8

12

10

times10minus39

d2120590d

T120583d(c

os 120579 120583

)(c

m2G

eV)


(b)


2molecule

times10minus39

012

01

008

006

004

002

0 50 100 150 200 250 300 350 400


MC prediction


120597120590120597(K

E 120587)

(cm

2M

eV)

(a)

times10minus39

35

30

25

20

15

10

5

00 02 04 06 08 1 12 14


p120587∘ (GeVc)

120597120590120597p120587∘(

120583N


998400 )(c

m2G

eVc

CH2)

(b)







]120583(]120583) + 119901 997888rarr ]

120583(]120583) + 119901

]120583(]120583) + 119899 997888rarr ]

120583(]120583) + 119899

(4)


1800

1600

1400

1200

1000

800

600

400

200

0100 200 300 400 500 600



Even

ts24

MeV

(a)

times10minus39

2

15

1

05

002 04 06 08 1 12 14 16



d120590d

Q2 Q

E(c

m2G

eV2)

Q2QE (GeV2)


(b)


2 region



2target




119873 Using this


1198762

119876119864= 2119872

119873sum119879119873 (5)


119876119864

physical















05

04

03

02

01

350 400 450 500 550 600 650 700 750

(prarr

p)(N

rarrN

)on

CH

2


T (MeV)










120583rarr ]

119890


120583rarr ]




12

10

08

06

04

02

02 04 06 08 10 12 14 15 30

Antineutrino


e from K+minus

e from K0

120587∘ misid

DirtOther

Δ rarr N120574

Constr syst error

Even

tsM

eV

EQE (GeV)

25

20

15

10

05

00

Neutrino

02 04 06 08 10 12 14 15 30


e from K+minus

e from K0

120587∘ misid

DirtOther

Δ rarr N120574

Constr syst error

Even

tsM

eV

EQE (GeV)

(a)

Antineutrino

102

10

1

10minus1



9599

Δm

2(e

V2)

sin2 2120579

Neutrino

10

1

10minus1

10minus2



6890

9599

ICARUS 90 CL

Δm

2(e

V2)

sin2 2120579

(b)















NN

Z

120574

120596






ℎlt





0018

0016

0014

0012

001

0008

0006

0004

0002

00 05 1 15 2 25 3

E (GeV)

GENIENEUTNUANCE


120590(10minus

38cm

212C)


N N

Z

120574

120583 120583

h


















HD foamsaddles

end-cap


Drift

Weldedremovable











L =1

2119894120595119860Γ120583

119860119861

harr

119863120583120595119861minus 120595119860119872119860119861120595119861+ ℎ119888 (6)

Γ]119860119861

= 120574]120575119860119861

+ 119888120583]119860119861120574120583+ 119889120583]1198601198611205745120574120583+ 119890

]119860119861

+ 119894119891]1198601198611205745+1

2119892120582120583]119860119861

120590120582120583

(7)

119872119860119861

= 119898119860119861

+ 1198941198985119860119861

1205745+ 119886120583

119860119861120574120583+ 119887120583

119860119861+1

2119867120583]119860119861120590120583] (8)





120583rarr ]119890(]120583rarr ]119890)



8070605040302010

0 10000 20000 30000 40000 50000 60000 70000 80000

-os

c can

dida

te ev

ents

Sidereal time (s)

Data

Background


5-parameter fit

(a)

-os

c can

dida

te ev

ents 40

3530252015

5

0 10000 20000 30000 40000 50000 60000 70000 80000

Sidereal time (s)

Data

Background


10


(b)








1100

1000

900

800

700

600

500

40060 80 100 120 140 160 180 200 220 240

E (MeV)

Even

ts


Preliminary

Best fit (M120594 = 150MeV 120581 = 00024)


Protonbeam



120587+ rarr 120583+120583120594 + e rarr

120594 + e

120583+ rarr e+e120583




10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary




N120594 rarr N120594 120572998400 = 01

ΔmZ and EW fit

(a)


10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary



e120594 rarr e120594 120572998400 = 01

ΔmZ and EW fit

(b)





L = L119878119872

minus1

41198812

120583] +1

21198982

1198811198812

120583+ 120581119881]120597120583119865

120583]

+1003816100381610038161003816100381611986312058312059410038161003816100381610038161003816

2

minus 1198982

120594

10038161003816100381610038161205941003816100381610038161003816

2

+ sdot sdot sdot

(9)



119881 kinetic




120594=






01 1



e120594 rarr e120594N120594 rarr N120594

10minus1

10minus2

10minus3

10minus4

mV (GeV)


m120594 = 10MeV m120594 = 10MeV



01 1



10minus1

10minus2

10minus3

10minus4

mV (GeV)



120572998400 = 01120572998400 = 01

120581120581
















119881phase




WIMP time of flight

50m dump

50m decay pipe


8GeVprotons


490m = 1633 ns at c





7 Conclusion


1800

1600

1400

1200

1000

800

600

400

200

00 2 4 6 8 10 12 14 16 18 20

Preliminary

Bunch time (ns)


BkgDirtStrobe

Even

ts




Acknowledgments


References






























119901 rarr119901)16F





















120583and ]









1























119890appearance at









































































FluidsJournal of


Journal of










Superconductivity




GravityJournal of








Journal of






Volume 2014


PhotonicsJournal of


Journal of

Biophysics







120583(]120583) and ]

119890(]119890)


]120583+ 119899 997888rarr 120583

minus+ 119901

]120583+ 119901 997888rarr 120583

++ 119899

]119890+ 119899 997888rarr 119890

minus+ 119901

]119890+ 119901 997888rarr 119890

++ 119899

(2)




120583











]120583+ CH

2997888rarr 120583minus+ 120587++ 119883

]120583+ CH

2997888rarr 120583minus+ 120587∘+ 119883

]120583(]120583) + CH

2+ 997888rarr ]

120583(]120583) + 120587∘+ 119883

(3)



02 04 06 08 1 12 14 16 18 2

106

02minus02

minus06minus1

cos 120579120583

T120583 (GeV)

0

5

10

15

20

25

times10minus39


Shape uncertainty

d2120590d

T120583d(c

os 120579 120583

)(c

m2G

eV)

(a)

02 04 06 08 1 12 14 16 18 2

106

02minus02

minus06minus1

cos 120579120583

T120583 (GeV)

0

2

4

6

8

12

10

times10minus39

d2120590d

T120583d(c

os 120579 120583

)(c

m2G

eV)


(b)


2molecule

times10minus39

012

01

008

006

004

002

0 50 100 150 200 250 300 350 400


MC prediction


120597120590120597(K

E 120587)

(cm

2M

eV)

(a)

times10minus39

35

30

25

20

15

10

5

00 02 04 06 08 1 12 14


p120587∘ (GeVc)

120597120590120597p120587∘(

120583N


998400 )(c

m2G

eVc

CH2)

(b)







]120583(]120583) + 119901 997888rarr ]

120583(]120583) + 119901

]120583(]120583) + 119899 997888rarr ]

120583(]120583) + 119899

(4)


1800

1600

1400

1200

1000

800

600

400

200

0100 200 300 400 500 600



Even

ts24

MeV

(a)

times10minus39

2

15

1

05

002 04 06 08 1 12 14 16



d120590d

Q2 Q

E(c

m2G

eV2)

Q2QE (GeV2)


(b)


2 region



2target




119873 Using this


1198762

119876119864= 2119872

119873sum119879119873 (5)


119876119864

physical















05

04

03

02

01

350 400 450 500 550 600 650 700 750

(prarr

p)(N

rarrN

)on

CH

2


T (MeV)










120583rarr ]

119890


120583rarr ]




12

10

08

06

04

02

02 04 06 08 10 12 14 15 30

Antineutrino


e from K+minus

e from K0

120587∘ misid

DirtOther

Δ rarr N120574

Constr syst error

Even

tsM

eV

EQE (GeV)

25

20

15

10

05

00

Neutrino

02 04 06 08 10 12 14 15 30


e from K+minus

e from K0

120587∘ misid

DirtOther

Δ rarr N120574

Constr syst error

Even

tsM

eV

EQE (GeV)

(a)

Antineutrino

102

10

1

10minus1



9599

Δm

2(e

V2)

sin2 2120579

Neutrino

10

1

10minus1

10minus2



6890

9599

ICARUS 90 CL

Δm

2(e

V2)

sin2 2120579

(b)















NN

Z

120574

120596






ℎlt





0018

0016

0014

0012

001

0008

0006

0004

0002

00 05 1 15 2 25 3

E (GeV)

GENIENEUTNUANCE


120590(10minus

38cm

212C)


N N

Z

120574

120583 120583

h


















HD foamsaddles

end-cap


Drift

Weldedremovable











L =1

2119894120595119860Γ120583

119860119861

harr

119863120583120595119861minus 120595119860119872119860119861120595119861+ ℎ119888 (6)

Γ]119860119861

= 120574]120575119860119861

+ 119888120583]119860119861120574120583+ 119889120583]1198601198611205745120574120583+ 119890

]119860119861

+ 119894119891]1198601198611205745+1

2119892120582120583]119860119861

120590120582120583

(7)

119872119860119861

= 119898119860119861

+ 1198941198985119860119861

1205745+ 119886120583

119860119861120574120583+ 119887120583

119860119861+1

2119867120583]119860119861120590120583] (8)





120583rarr ]119890(]120583rarr ]119890)



8070605040302010

0 10000 20000 30000 40000 50000 60000 70000 80000

-os

c can

dida

te ev

ents

Sidereal time (s)

Data

Background


5-parameter fit

(a)

-os

c can

dida

te ev

ents 40

3530252015

5

0 10000 20000 30000 40000 50000 60000 70000 80000

Sidereal time (s)

Data

Background


10


(b)








1100

1000

900

800

700

600

500

40060 80 100 120 140 160 180 200 220 240

E (MeV)

Even

ts


Preliminary

Best fit (M120594 = 150MeV 120581 = 00024)


Protonbeam



120587+ rarr 120583+120583120594 + e rarr

120594 + e

120583+ rarr e+e120583




10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary




N120594 rarr N120594 120572998400 = 01

ΔmZ and EW fit

(a)


10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary



e120594 rarr e120594 120572998400 = 01

ΔmZ and EW fit

(b)





L = L119878119872

minus1

41198812

120583] +1

21198982

1198811198812

120583+ 120581119881]120597120583119865

120583]

+1003816100381610038161003816100381611986312058312059410038161003816100381610038161003816

2

minus 1198982

120594

10038161003816100381610038161205941003816100381610038161003816

2

+ sdot sdot sdot

(9)



119881 kinetic




120594=






01 1



e120594 rarr e120594N120594 rarr N120594

10minus1

10minus2

10minus3

10minus4

mV (GeV)


m120594 = 10MeV m120594 = 10MeV



01 1



10minus1

10minus2

10minus3

10minus4

mV (GeV)



120572998400 = 01120572998400 = 01

120581120581
















119881phase




WIMP time of flight

50m dump

50m decay pipe


8GeVprotons


490m = 1633 ns at c





7 Conclusion


1800

1600

1400

1200

1000

800

600

400

200

00 2 4 6 8 10 12 14 16 18 20

Preliminary

Bunch time (ns)


BkgDirtStrobe

Even

ts




Acknowledgments


References






























119901 rarr119901)16F





















120583and ]









1























119890appearance at









































































FluidsJournal of


Journal of










Superconductivity




GravityJournal of








Journal of






Volume 2014


PhotonicsJournal of


Journal of

Biophysics




02 04 06 08 1 12 14 16 18 2

106

02minus02

minus06minus1

cos 120579120583

T120583 (GeV)

0

5

10

15

20

25

times10minus39


Shape uncertainty

d2120590d

T120583d(c

os 120579 120583

)(c

m2G

eV)

(a)

02 04 06 08 1 12 14 16 18 2

106

02minus02

minus06minus1

cos 120579120583

T120583 (GeV)

0

2

4

6

8

12

10

times10minus39

d2120590d

T120583d(c

os 120579 120583

)(c

m2G

eV)


(b)


2molecule

times10minus39

012

01

008

006

004

002

0 50 100 150 200 250 300 350 400


MC prediction


120597120590120597(K

E 120587)

(cm

2M

eV)

(a)

times10minus39

35

30

25

20

15

10

5

00 02 04 06 08 1 12 14


p120587∘ (GeVc)

120597120590120597p120587∘(

120583N


998400 )(c

m2G

eVc

CH2)

(b)







]120583(]120583) + 119901 997888rarr ]

120583(]120583) + 119901

]120583(]120583) + 119899 997888rarr ]

120583(]120583) + 119899

(4)


1800

1600

1400

1200

1000

800

600

400

200

0100 200 300 400 500 600



Even

ts24

MeV

(a)

times10minus39

2

15

1

05

002 04 06 08 1 12 14 16



d120590d

Q2 Q

E(c

m2G

eV2)

Q2QE (GeV2)


(b)


2 region



2target




119873 Using this


1198762

119876119864= 2119872

119873sum119879119873 (5)


119876119864

physical















05

04

03

02

01

350 400 450 500 550 600 650 700 750

(prarr

p)(N

rarrN

)on

CH

2


T (MeV)










120583rarr ]

119890


120583rarr ]




12

10

08

06

04

02

02 04 06 08 10 12 14 15 30

Antineutrino


e from K+minus

e from K0

120587∘ misid

DirtOther

Δ rarr N120574

Constr syst error

Even

tsM

eV

EQE (GeV)

25

20

15

10

05

00

Neutrino

02 04 06 08 10 12 14 15 30


e from K+minus

e from K0

120587∘ misid

DirtOther

Δ rarr N120574

Constr syst error

Even

tsM

eV

EQE (GeV)

(a)

Antineutrino

102

10

1

10minus1



9599

Δm

2(e

V2)

sin2 2120579

Neutrino

10

1

10minus1

10minus2



6890

9599

ICARUS 90 CL

Δm

2(e

V2)

sin2 2120579

(b)















NN

Z

120574

120596






ℎlt





0018

0016

0014

0012

001

0008

0006

0004

0002

00 05 1 15 2 25 3

E (GeV)

GENIENEUTNUANCE


120590(10minus

38cm

212C)


N N

Z

120574

120583 120583

h


















HD foamsaddles

end-cap


Drift

Weldedremovable











L =1

2119894120595119860Γ120583

119860119861

harr

119863120583120595119861minus 120595119860119872119860119861120595119861+ ℎ119888 (6)

Γ]119860119861

= 120574]120575119860119861

+ 119888120583]119860119861120574120583+ 119889120583]1198601198611205745120574120583+ 119890

]119860119861

+ 119894119891]1198601198611205745+1

2119892120582120583]119860119861

120590120582120583

(7)

119872119860119861

= 119898119860119861

+ 1198941198985119860119861

1205745+ 119886120583

119860119861120574120583+ 119887120583

119860119861+1

2119867120583]119860119861120590120583] (8)





120583rarr ]119890(]120583rarr ]119890)



8070605040302010

0 10000 20000 30000 40000 50000 60000 70000 80000

-os

c can

dida

te ev

ents

Sidereal time (s)

Data

Background


5-parameter fit

(a)

-os

c can

dida

te ev

ents 40

3530252015

5

0 10000 20000 30000 40000 50000 60000 70000 80000

Sidereal time (s)

Data

Background


10


(b)








1100

1000

900

800

700

600

500

40060 80 100 120 140 160 180 200 220 240

E (MeV)

Even

ts


Preliminary

Best fit (M120594 = 150MeV 120581 = 00024)


Protonbeam



120587+ rarr 120583+120583120594 + e rarr

120594 + e

120583+ rarr e+e120583




10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary




N120594 rarr N120594 120572998400 = 01

ΔmZ and EW fit

(a)


10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary



e120594 rarr e120594 120572998400 = 01

ΔmZ and EW fit

(b)





L = L119878119872

minus1

41198812

120583] +1

21198982

1198811198812

120583+ 120581119881]120597120583119865

120583]

+1003816100381610038161003816100381611986312058312059410038161003816100381610038161003816

2

minus 1198982

120594

10038161003816100381610038161205941003816100381610038161003816

2

+ sdot sdot sdot

(9)



119881 kinetic




120594=






01 1



e120594 rarr e120594N120594 rarr N120594

10minus1

10minus2

10minus3

10minus4

mV (GeV)


m120594 = 10MeV m120594 = 10MeV



01 1



10minus1

10minus2

10minus3

10minus4

mV (GeV)



120572998400 = 01120572998400 = 01

120581120581
















119881phase




WIMP time of flight

50m dump

50m decay pipe


8GeVprotons


490m = 1633 ns at c





7 Conclusion


1800

1600

1400

1200

1000

800

600

400

200

00 2 4 6 8 10 12 14 16 18 20

Preliminary

Bunch time (ns)


BkgDirtStrobe

Even

ts




Acknowledgments


References






























119901 rarr119901)16F





















120583and ]









1























119890appearance at









































































FluidsJournal of


Journal of










Superconductivity




GravityJournal of








Journal of






Volume 2014


PhotonicsJournal of


Journal of

Biophysics




1800

1600

1400

1200

1000

800

600

400

200

0100 200 300 400 500 600



Even

ts24

MeV

(a)

times10minus39

2

15

1

05

002 04 06 08 1 12 14 16



d120590d

Q2 Q

E(c

m2G

eV2)

Q2QE (GeV2)


(b)


2 region



2target




119873 Using this


1198762

119876119864= 2119872

119873sum119879119873 (5)


119876119864

physical















05

04

03

02

01

350 400 450 500 550 600 650 700 750

(prarr

p)(N

rarrN

)on

CH

2


T (MeV)










120583rarr ]

119890


120583rarr ]




12

10

08

06

04

02

02 04 06 08 10 12 14 15 30

Antineutrino


e from K+minus

e from K0

120587∘ misid

DirtOther

Δ rarr N120574

Constr syst error

Even

tsM

eV

EQE (GeV)

25

20

15

10

05

00

Neutrino

02 04 06 08 10 12 14 15 30


e from K+minus

e from K0

120587∘ misid

DirtOther

Δ rarr N120574

Constr syst error

Even

tsM

eV

EQE (GeV)

(a)

Antineutrino

102

10

1

10minus1



9599

Δm

2(e

V2)

sin2 2120579

Neutrino

10

1

10minus1

10minus2



6890

9599

ICARUS 90 CL

Δm

2(e

V2)

sin2 2120579

(b)















NN

Z

120574

120596






ℎlt





0018

0016

0014

0012

001

0008

0006

0004

0002

00 05 1 15 2 25 3

E (GeV)

GENIENEUTNUANCE


120590(10minus

38cm

212C)


N N

Z

120574

120583 120583

h


















HD foamsaddles

end-cap


Drift

Weldedremovable











L =1

2119894120595119860Γ120583

119860119861

harr

119863120583120595119861minus 120595119860119872119860119861120595119861+ ℎ119888 (6)

Γ]119860119861

= 120574]120575119860119861

+ 119888120583]119860119861120574120583+ 119889120583]1198601198611205745120574120583+ 119890

]119860119861

+ 119894119891]1198601198611205745+1

2119892120582120583]119860119861

120590120582120583

(7)

119872119860119861

= 119898119860119861

+ 1198941198985119860119861

1205745+ 119886120583

119860119861120574120583+ 119887120583

119860119861+1

2119867120583]119860119861120590120583] (8)





120583rarr ]119890(]120583rarr ]119890)



8070605040302010

0 10000 20000 30000 40000 50000 60000 70000 80000

-os

c can

dida

te ev

ents

Sidereal time (s)

Data

Background


5-parameter fit

(a)

-os

c can

dida

te ev

ents 40

3530252015

5

0 10000 20000 30000 40000 50000 60000 70000 80000

Sidereal time (s)

Data

Background


10


(b)








1100

1000

900

800

700

600

500

40060 80 100 120 140 160 180 200 220 240

E (MeV)

Even

ts


Preliminary

Best fit (M120594 = 150MeV 120581 = 00024)


Protonbeam



120587+ rarr 120583+120583120594 + e rarr

120594 + e

120583+ rarr e+e120583




10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary




N120594 rarr N120594 120572998400 = 01

ΔmZ and EW fit

(a)


10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary



e120594 rarr e120594 120572998400 = 01

ΔmZ and EW fit

(b)





L = L119878119872

minus1

41198812

120583] +1

21198982

1198811198812

120583+ 120581119881]120597120583119865

120583]

+1003816100381610038161003816100381611986312058312059410038161003816100381610038161003816

2

minus 1198982

120594

10038161003816100381610038161205941003816100381610038161003816

2

+ sdot sdot sdot

(9)



119881 kinetic




120594=






01 1



e120594 rarr e120594N120594 rarr N120594

10minus1

10minus2

10minus3

10minus4

mV (GeV)


m120594 = 10MeV m120594 = 10MeV



01 1



10minus1

10minus2

10minus3

10minus4

mV (GeV)



120572998400 = 01120572998400 = 01

120581120581
















119881phase




WIMP time of flight

50m dump

50m decay pipe


8GeVprotons


490m = 1633 ns at c





7 Conclusion


1800

1600

1400

1200

1000

800

600

400

200

00 2 4 6 8 10 12 14 16 18 20

Preliminary

Bunch time (ns)


BkgDirtStrobe

Even

ts




Acknowledgments


References






























119901 rarr119901)16F





















120583and ]









1























119890appearance at









































































FluidsJournal of


Journal of










Superconductivity




GravityJournal of








Journal of






Volume 2014


PhotonicsJournal of


Journal of

Biophysics













05

04

03

02

01

350 400 450 500 550 600 650 700 750

(prarr

p)(N

rarrN

)on

CH

2


T (MeV)










120583rarr ]

119890


120583rarr ]




12

10

08

06

04

02

02 04 06 08 10 12 14 15 30

Antineutrino


e from K+minus

e from K0

120587∘ misid

DirtOther

Δ rarr N120574

Constr syst error

Even

tsM

eV

EQE (GeV)

25

20

15

10

05

00

Neutrino

02 04 06 08 10 12 14 15 30


e from K+minus

e from K0

120587∘ misid

DirtOther

Δ rarr N120574

Constr syst error

Even

tsM

eV

EQE (GeV)

(a)

Antineutrino

102

10

1

10minus1



9599

Δm

2(e

V2)

sin2 2120579

Neutrino

10

1

10minus1

10minus2



6890

9599

ICARUS 90 CL

Δm

2(e

V2)

sin2 2120579

(b)















NN

Z

120574

120596






ℎlt





0018

0016

0014

0012

001

0008

0006

0004

0002

00 05 1 15 2 25 3

E (GeV)

GENIENEUTNUANCE


120590(10minus

38cm

212C)


N N

Z

120574

120583 120583

h


















HD foamsaddles

end-cap


Drift

Weldedremovable











L =1

2119894120595119860Γ120583

119860119861

harr

119863120583120595119861minus 120595119860119872119860119861120595119861+ ℎ119888 (6)

Γ]119860119861

= 120574]120575119860119861

+ 119888120583]119860119861120574120583+ 119889120583]1198601198611205745120574120583+ 119890

]119860119861

+ 119894119891]1198601198611205745+1

2119892120582120583]119860119861

120590120582120583

(7)

119872119860119861

= 119898119860119861

+ 1198941198985119860119861

1205745+ 119886120583

119860119861120574120583+ 119887120583

119860119861+1

2119867120583]119860119861120590120583] (8)





120583rarr ]119890(]120583rarr ]119890)



8070605040302010

0 10000 20000 30000 40000 50000 60000 70000 80000

-os

c can

dida

te ev

ents

Sidereal time (s)

Data

Background


5-parameter fit

(a)

-os

c can

dida

te ev

ents 40

3530252015

5

0 10000 20000 30000 40000 50000 60000 70000 80000

Sidereal time (s)

Data

Background


10


(b)








1100

1000

900

800

700

600

500

40060 80 100 120 140 160 180 200 220 240

E (MeV)

Even

ts


Preliminary

Best fit (M120594 = 150MeV 120581 = 00024)


Protonbeam



120587+ rarr 120583+120583120594 + e rarr

120594 + e

120583+ rarr e+e120583




10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary




N120594 rarr N120594 120572998400 = 01

ΔmZ and EW fit

(a)


10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary



e120594 rarr e120594 120572998400 = 01

ΔmZ and EW fit

(b)





L = L119878119872

minus1

41198812

120583] +1

21198982

1198811198812

120583+ 120581119881]120597120583119865

120583]

+1003816100381610038161003816100381611986312058312059410038161003816100381610038161003816

2

minus 1198982

120594

10038161003816100381610038161205941003816100381610038161003816

2

+ sdot sdot sdot

(9)



119881 kinetic




120594=






01 1



e120594 rarr e120594N120594 rarr N120594

10minus1

10minus2

10minus3

10minus4

mV (GeV)


m120594 = 10MeV m120594 = 10MeV



01 1



10minus1

10minus2

10minus3

10minus4

mV (GeV)



120572998400 = 01120572998400 = 01

120581120581
















119881phase




WIMP time of flight

50m dump

50m decay pipe


8GeVprotons


490m = 1633 ns at c





7 Conclusion


1800

1600

1400

1200

1000

800

600

400

200

00 2 4 6 8 10 12 14 16 18 20

Preliminary

Bunch time (ns)


BkgDirtStrobe

Even

ts




Acknowledgments


References






























119901 rarr119901)16F





















120583and ]









1























119890appearance at









































































FluidsJournal of


Journal of










Superconductivity




GravityJournal of








Journal of






Volume 2014


PhotonicsJournal of


Journal of

Biophysics




12

10

08

06

04

02

02 04 06 08 10 12 14 15 30

Antineutrino


e from K+minus

e from K0

120587∘ misid

DirtOther

Δ rarr N120574

Constr syst error

Even

tsM

eV

EQE (GeV)

25

20

15

10

05

00

Neutrino

02 04 06 08 10 12 14 15 30


e from K+minus

e from K0

120587∘ misid

DirtOther

Δ rarr N120574

Constr syst error

Even

tsM

eV

EQE (GeV)

(a)

Antineutrino

102

10

1

10minus1



9599

Δm

2(e

V2)

sin2 2120579

Neutrino

10

1

10minus1

10minus2



6890

9599

ICARUS 90 CL

Δm

2(e

V2)

sin2 2120579

(b)















NN

Z

120574

120596






ℎlt





0018

0016

0014

0012

001

0008

0006

0004

0002

00 05 1 15 2 25 3

E (GeV)

GENIENEUTNUANCE


120590(10minus

38cm

212C)


N N

Z

120574

120583 120583

h


















HD foamsaddles

end-cap


Drift

Weldedremovable











L =1

2119894120595119860Γ120583

119860119861

harr

119863120583120595119861minus 120595119860119872119860119861120595119861+ ℎ119888 (6)

Γ]119860119861

= 120574]120575119860119861

+ 119888120583]119860119861120574120583+ 119889120583]1198601198611205745120574120583+ 119890

]119860119861

+ 119894119891]1198601198611205745+1

2119892120582120583]119860119861

120590120582120583

(7)

119872119860119861

= 119898119860119861

+ 1198941198985119860119861

1205745+ 119886120583

119860119861120574120583+ 119887120583

119860119861+1

2119867120583]119860119861120590120583] (8)





120583rarr ]119890(]120583rarr ]119890)



8070605040302010

0 10000 20000 30000 40000 50000 60000 70000 80000

-os

c can

dida

te ev

ents

Sidereal time (s)

Data

Background


5-parameter fit

(a)

-os

c can

dida

te ev

ents 40

3530252015

5

0 10000 20000 30000 40000 50000 60000 70000 80000

Sidereal time (s)

Data

Background


10


(b)








1100

1000

900

800

700

600

500

40060 80 100 120 140 160 180 200 220 240

E (MeV)

Even

ts


Preliminary

Best fit (M120594 = 150MeV 120581 = 00024)


Protonbeam



120587+ rarr 120583+120583120594 + e rarr

120594 + e

120583+ rarr e+e120583




10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary




N120594 rarr N120594 120572998400 = 01

ΔmZ and EW fit

(a)


10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary



e120594 rarr e120594 120572998400 = 01

ΔmZ and EW fit

(b)





L = L119878119872

minus1

41198812

120583] +1

21198982

1198811198812

120583+ 120581119881]120597120583119865

120583]

+1003816100381610038161003816100381611986312058312059410038161003816100381610038161003816

2

minus 1198982

120594

10038161003816100381610038161205941003816100381610038161003816

2

+ sdot sdot sdot

(9)



119881 kinetic




120594=






01 1



e120594 rarr e120594N120594 rarr N120594

10minus1

10minus2

10minus3

10minus4

mV (GeV)


m120594 = 10MeV m120594 = 10MeV



01 1



10minus1

10minus2

10minus3

10minus4

mV (GeV)



120572998400 = 01120572998400 = 01

120581120581
















119881phase




WIMP time of flight

50m dump

50m decay pipe


8GeVprotons


490m = 1633 ns at c





7 Conclusion


1800

1600

1400

1200

1000

800

600

400

200

00 2 4 6 8 10 12 14 16 18 20

Preliminary

Bunch time (ns)


BkgDirtStrobe

Even

ts




Acknowledgments


References






























119901 rarr119901)16F





















120583and ]









1























119890appearance at









































































FluidsJournal of


Journal of










Superconductivity




GravityJournal of








Journal of






Volume 2014


PhotonicsJournal of


Journal of

Biophysics










NN

Z

120574

120596






ℎlt





0018

0016

0014

0012

001

0008

0006

0004

0002

00 05 1 15 2 25 3

E (GeV)

GENIENEUTNUANCE


120590(10minus

38cm

212C)


N N

Z

120574

120583 120583

h


















HD foamsaddles

end-cap


Drift

Weldedremovable











L =1

2119894120595119860Γ120583

119860119861

harr

119863120583120595119861minus 120595119860119872119860119861120595119861+ ℎ119888 (6)

Γ]119860119861

= 120574]120575119860119861

+ 119888120583]119860119861120574120583+ 119889120583]1198601198611205745120574120583+ 119890

]119860119861

+ 119894119891]1198601198611205745+1

2119892120582120583]119860119861

120590120582120583

(7)

119872119860119861

= 119898119860119861

+ 1198941198985119860119861

1205745+ 119886120583

119860119861120574120583+ 119887120583

119860119861+1

2119867120583]119860119861120590120583] (8)





120583rarr ]119890(]120583rarr ]119890)



8070605040302010

0 10000 20000 30000 40000 50000 60000 70000 80000

-os

c can

dida

te ev

ents

Sidereal time (s)

Data

Background


5-parameter fit

(a)

-os

c can

dida

te ev

ents 40

3530252015

5

0 10000 20000 30000 40000 50000 60000 70000 80000

Sidereal time (s)

Data

Background


10


(b)








1100

1000

900

800

700

600

500

40060 80 100 120 140 160 180 200 220 240

E (MeV)

Even

ts


Preliminary

Best fit (M120594 = 150MeV 120581 = 00024)


Protonbeam



120587+ rarr 120583+120583120594 + e rarr

120594 + e

120583+ rarr e+e120583




10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary




N120594 rarr N120594 120572998400 = 01

ΔmZ and EW fit

(a)


10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary



e120594 rarr e120594 120572998400 = 01

ΔmZ and EW fit

(b)





L = L119878119872

minus1

41198812

120583] +1

21198982

1198811198812

120583+ 120581119881]120597120583119865

120583]

+1003816100381610038161003816100381611986312058312059410038161003816100381610038161003816

2

minus 1198982

120594

10038161003816100381610038161205941003816100381610038161003816

2

+ sdot sdot sdot

(9)



119881 kinetic




120594=






01 1



e120594 rarr e120594N120594 rarr N120594

10minus1

10minus2

10minus3

10minus4

mV (GeV)


m120594 = 10MeV m120594 = 10MeV



01 1



10minus1

10minus2

10minus3

10minus4

mV (GeV)



120572998400 = 01120572998400 = 01

120581120581
















119881phase




WIMP time of flight

50m dump

50m decay pipe


8GeVprotons


490m = 1633 ns at c





7 Conclusion


1800

1600

1400

1200

1000

800

600

400

200

00 2 4 6 8 10 12 14 16 18 20

Preliminary

Bunch time (ns)


BkgDirtStrobe

Even

ts




Acknowledgments


References






























119901 rarr119901)16F





















120583and ]









1























119890appearance at









































































FluidsJournal of


Journal of










Superconductivity




GravityJournal of








Journal of






Volume 2014


PhotonicsJournal of


Journal of

Biophysics




0018

0016

0014

0012

001

0008

0006

0004

0002

00 05 1 15 2 25 3

E (GeV)

GENIENEUTNUANCE


120590(10minus

38cm

212C)


N N

Z

120574

120583 120583

h


















HD foamsaddles

end-cap


Drift

Weldedremovable











L =1

2119894120595119860Γ120583

119860119861

harr

119863120583120595119861minus 120595119860119872119860119861120595119861+ ℎ119888 (6)

Γ]119860119861

= 120574]120575119860119861

+ 119888120583]119860119861120574120583+ 119889120583]1198601198611205745120574120583+ 119890

]119860119861

+ 119894119891]1198601198611205745+1

2119892120582120583]119860119861

120590120582120583

(7)

119872119860119861

= 119898119860119861

+ 1198941198985119860119861

1205745+ 119886120583

119860119861120574120583+ 119887120583

119860119861+1

2119867120583]119860119861120590120583] (8)





120583rarr ]119890(]120583rarr ]119890)



8070605040302010

0 10000 20000 30000 40000 50000 60000 70000 80000

-os

c can

dida

te ev

ents

Sidereal time (s)

Data

Background


5-parameter fit

(a)

-os

c can

dida

te ev

ents 40

3530252015

5

0 10000 20000 30000 40000 50000 60000 70000 80000

Sidereal time (s)

Data

Background


10


(b)








1100

1000

900

800

700

600

500

40060 80 100 120 140 160 180 200 220 240

E (MeV)

Even

ts


Preliminary

Best fit (M120594 = 150MeV 120581 = 00024)


Protonbeam



120587+ rarr 120583+120583120594 + e rarr

120594 + e

120583+ rarr e+e120583




10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary




N120594 rarr N120594 120572998400 = 01

ΔmZ and EW fit

(a)


10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary



e120594 rarr e120594 120572998400 = 01

ΔmZ and EW fit

(b)





L = L119878119872

minus1

41198812

120583] +1

21198982

1198811198812

120583+ 120581119881]120597120583119865

120583]

+1003816100381610038161003816100381611986312058312059410038161003816100381610038161003816

2

minus 1198982

120594

10038161003816100381610038161205941003816100381610038161003816

2

+ sdot sdot sdot

(9)



119881 kinetic




120594=






01 1



e120594 rarr e120594N120594 rarr N120594

10minus1

10minus2

10minus3

10minus4

mV (GeV)


m120594 = 10MeV m120594 = 10MeV



01 1



10minus1

10minus2

10minus3

10minus4

mV (GeV)



120572998400 = 01120572998400 = 01

120581120581
















119881phase




WIMP time of flight

50m dump

50m decay pipe


8GeVprotons


490m = 1633 ns at c





7 Conclusion


1800

1600

1400

1200

1000

800

600

400

200

00 2 4 6 8 10 12 14 16 18 20

Preliminary

Bunch time (ns)


BkgDirtStrobe

Even

ts




Acknowledgments


References






























119901 rarr119901)16F





















120583and ]









1























119890appearance at









































































FluidsJournal of


Journal of










Superconductivity




GravityJournal of








Journal of






Volume 2014


PhotonicsJournal of


Journal of

Biophysics




HD foamsaddles

end-cap


Drift

Weldedremovable











L =1

2119894120595119860Γ120583

119860119861

harr

119863120583120595119861minus 120595119860119872119860119861120595119861+ ℎ119888 (6)

Γ]119860119861

= 120574]120575119860119861

+ 119888120583]119860119861120574120583+ 119889120583]1198601198611205745120574120583+ 119890

]119860119861

+ 119894119891]1198601198611205745+1

2119892120582120583]119860119861

120590120582120583

(7)

119872119860119861

= 119898119860119861

+ 1198941198985119860119861

1205745+ 119886120583

119860119861120574120583+ 119887120583

119860119861+1

2119867120583]119860119861120590120583] (8)





120583rarr ]119890(]120583rarr ]119890)



8070605040302010

0 10000 20000 30000 40000 50000 60000 70000 80000

-os

c can

dida

te ev

ents

Sidereal time (s)

Data

Background


5-parameter fit

(a)

-os

c can

dida

te ev

ents 40

3530252015

5

0 10000 20000 30000 40000 50000 60000 70000 80000

Sidereal time (s)

Data

Background


10


(b)








1100

1000

900

800

700

600

500

40060 80 100 120 140 160 180 200 220 240

E (MeV)

Even

ts


Preliminary

Best fit (M120594 = 150MeV 120581 = 00024)


Protonbeam



120587+ rarr 120583+120583120594 + e rarr

120594 + e

120583+ rarr e+e120583




10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary




N120594 rarr N120594 120572998400 = 01

ΔmZ and EW fit

(a)


10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary



e120594 rarr e120594 120572998400 = 01

ΔmZ and EW fit

(b)





L = L119878119872

minus1

41198812

120583] +1

21198982

1198811198812

120583+ 120581119881]120597120583119865

120583]

+1003816100381610038161003816100381611986312058312059410038161003816100381610038161003816

2

minus 1198982

120594

10038161003816100381610038161205941003816100381610038161003816

2

+ sdot sdot sdot

(9)



119881 kinetic




120594=






01 1



e120594 rarr e120594N120594 rarr N120594

10minus1

10minus2

10minus3

10minus4

mV (GeV)


m120594 = 10MeV m120594 = 10MeV



01 1



10minus1

10minus2

10minus3

10minus4

mV (GeV)



120572998400 = 01120572998400 = 01

120581120581
















119881phase




WIMP time of flight

50m dump

50m decay pipe


8GeVprotons


490m = 1633 ns at c





7 Conclusion


1800

1600

1400

1200

1000

800

600

400

200

00 2 4 6 8 10 12 14 16 18 20

Preliminary

Bunch time (ns)


BkgDirtStrobe

Even

ts




Acknowledgments


References






























119901 rarr119901)16F





















120583and ]









1























119890appearance at









































































FluidsJournal of


Journal of










Superconductivity




GravityJournal of








Journal of






Volume 2014


PhotonicsJournal of


Journal of

Biophysics




8070605040302010

0 10000 20000 30000 40000 50000 60000 70000 80000

-os

c can

dida

te ev

ents

Sidereal time (s)

Data

Background


5-parameter fit

(a)

-os

c can

dida

te ev

ents 40

3530252015

5

0 10000 20000 30000 40000 50000 60000 70000 80000

Sidereal time (s)

Data

Background


10


(b)








1100

1000

900

800

700

600

500

40060 80 100 120 140 160 180 200 220 240

E (MeV)

Even

ts


Preliminary

Best fit (M120594 = 150MeV 120581 = 00024)


Protonbeam



120587+ rarr 120583+120583120594 + e rarr

120594 + e

120583+ rarr e+e120583




10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary




N120594 rarr N120594 120572998400 = 01

ΔmZ and EW fit

(a)


10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary



e120594 rarr e120594 120572998400 = 01

ΔmZ and EW fit

(b)





L = L119878119872

minus1

41198812

120583] +1

21198982

1198811198812

120583+ 120581119881]120597120583119865

120583]

+1003816100381610038161003816100381611986312058312059410038161003816100381610038161003816

2

minus 1198982

120594

10038161003816100381610038161205941003816100381610038161003816

2

+ sdot sdot sdot

(9)



119881 kinetic




120594=






01 1



e120594 rarr e120594N120594 rarr N120594

10minus1

10minus2

10minus3

10minus4

mV (GeV)


m120594 = 10MeV m120594 = 10MeV



01 1



10minus1

10minus2

10minus3

10minus4

mV (GeV)



120572998400 = 01120572998400 = 01

120581120581
















119881phase




WIMP time of flight

50m dump

50m decay pipe


8GeVprotons


490m = 1633 ns at c





7 Conclusion


1800

1600

1400

1200

1000

800

600

400

200

00 2 4 6 8 10 12 14 16 18 20

Preliminary

Bunch time (ns)


BkgDirtStrobe

Even

ts




Acknowledgments


References






























119901 rarr119901)16F





















120583and ]









1























119890appearance at









































































FluidsJournal of


Journal of










Superconductivity




GravityJournal of








Journal of






Volume 2014


PhotonicsJournal of


Journal of

Biophysics




10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary




N120594 rarr N120594 120572998400 = 01

ΔmZ and EW fit

(a)


10minus30

10minus32

10minus34

10minus36

10minus38

10minus40

10minus42001 01 1 10

120590N

(cm

2)

m120594 (GeV)

Preliminary



e120594 rarr e120594 120572998400 = 01

ΔmZ and EW fit

(b)





L = L119878119872

minus1

41198812

120583] +1

21198982

1198811198812

120583+ 120581119881]120597120583119865

120583]

+1003816100381610038161003816100381611986312058312059410038161003816100381610038161003816

2

minus 1198982

120594

10038161003816100381610038161205941003816100381610038161003816

2

+ sdot sdot sdot

(9)



119881 kinetic




120594=






01 1



e120594 rarr e120594N120594 rarr N120594

10minus1

10minus2

10minus3

10minus4

mV (GeV)


m120594 = 10MeV m120594 = 10MeV



01 1



10minus1

10minus2

10minus3

10minus4

mV (GeV)



120572998400 = 01120572998400 = 01

120581120581
















119881phase




WIMP time of flight

50m dump

50m decay pipe


8GeVprotons


490m = 1633 ns at c





7 Conclusion


1800

1600

1400

1200

1000

800

600

400

200

00 2 4 6 8 10 12 14 16 18 20

Preliminary

Bunch time (ns)


BkgDirtStrobe

Even

ts




Acknowledgments


References






























119901 rarr119901)16F





















120583and ]









1























119890appearance at









































































FluidsJournal of


Journal of










Superconductivity




GravityJournal of








Journal of






Volume 2014


PhotonicsJournal of


Journal of

Biophysics





01 1



e120594 rarr e120594N120594 rarr N120594

10minus1

10minus2

10minus3

10minus4

mV (GeV)


m120594 = 10MeV m120594 = 10MeV



01 1



10minus1

10minus2

10minus3

10minus4

mV (GeV)



120572998400 = 01120572998400 = 01

120581120581
















119881phase




WIMP time of flight

50m dump

50m decay pipe


8GeVprotons


490m = 1633 ns at c





7 Conclusion


1800

1600

1400

1200

1000

800

600

400

200

00 2 4 6 8 10 12 14 16 18 20

Preliminary

Bunch time (ns)


BkgDirtStrobe

Even

ts




Acknowledgments


References






























119901 rarr119901)16F





















120583and ]









1























119890appearance at









































































FluidsJournal of


Journal of










Superconductivity




GravityJournal of








Journal of






Volume 2014


PhotonicsJournal of


Journal of

Biophysics




WIMP time of flight

50m dump

50m decay pipe


8GeVprotons


490m = 1633 ns at c





7 Conclusion


1800

1600

1400

1200

1000

800

600

400

200

00 2 4 6 8 10 12 14 16 18 20

Preliminary

Bunch time (ns)


BkgDirtStrobe

Even

ts




Acknowledgments


References






























119901 rarr119901)16F





















120583and ]









1























119890appearance at









































































FluidsJournal of


Journal of










Superconductivity




GravityJournal of








Journal of






Volume 2014


PhotonicsJournal of


Journal of

Biophysics































119901 rarr119901)16F





















120583and ]









1























119890appearance at









































































FluidsJournal of


Journal of










Superconductivity




GravityJournal of








Journal of






Volume 2014


PhotonicsJournal of


Journal of

Biophysics









120583and ]









1























119890appearance at









































































FluidsJournal of


Journal of










Superconductivity




GravityJournal of








Journal of






Volume 2014


PhotonicsJournal of


Journal of

Biophysics































































FluidsJournal of


Journal of










Superconductivity




GravityJournal of








Journal of






Volume 2014


PhotonicsJournal of


Journal of

Biophysics



review article beyond standard model searches in the...

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