non-oscillation physics
DESCRIPTION
Non-oscillation physics. Report of the WG. M. Sioli, OPERA Collaboration Meeting, Ankara, 1-3 Apr 2009. OPERA-LVD coincidence study. People involved in this preliminary analysis: MS, Dario A. and Marco Selvi (LVD) People interested to join?. - PowerPoint PPT PresentationTRANSCRIPT
Non-oscillation physics
Report of the WG
M. Sioli, OPERA Collaboration Meeting, Ankara, 1-3 Apr 2009
OPERA-LVD coincidence study
The main physical motivation is the study high pT phenomena Large muon separation is the convolution of muon production height and
meson transverse momentum:
Roughly double the MACRO linear extension: MACRO ~70m OPERAT600 ~90m OPERALVD ~170m
At this distances/pT (> 2 GeV/c) we get inside pQCD predictions not strictly related to forward modeling
As a byproduct, also study beam events: large angle di-muon events? Video-meeting organized in Feb to define the initial steps
People involved in this preliminary analysis:MS, Dario A. and Marco Selvi (LVD)People interested to join?
Locations of the detectors in the Labs
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170 m
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R~D~1/(pT+p0)
R = muon-core distanceD = di-muon relative distance
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LVD detector• 3 identical towers in the detector
• 35 active modules in a tower
• 8 counters in one module
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The detector: basic elementsThe scintillation counter:
External dimensions: 1.5 x 1 x 1 m3
Scint. composition: CnH2n+2 <n>=9.6 +1 g/l PPO + 0.03 g/l POPOP
Scint. density: ~ 0.8 g/cm3
Attenuation lenght: > 15m @ =420 nm
Flash point at: ~39oC
PMT: FEU-49B Photocathode diameter: d=15 cmQuantum efficiency: 10-15%
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Statistics for OPERA and LVD
OPERA statistics (2008 run, 19th Jun 3rd Nov, extractions 682952): 644138 events (634390 cosmics + 9748 beam) 3151 hours of livetime (3287.7 elapsed) 95.8% dutycycle
cosmic’s rate: 0.056 Hz (average) beam’s rate: 0.00086 Hz
Taken from *_filter.rootfiles without any selection!
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Statistics for OPERA and LVD
LVD statistics (same period): 1152888 events (1139547 cosmics + 13341 beam) 3284.5 hours of livetime (3287.7 elapsed) 99.9% dutycycle
cosmic’s rate: 0.097 Hz (average) beam’s rate: 0.0011 Hz
● At least 2 different counters in coincidence inside 250 ns● Not tagged as HIGH RATE● Energy release > 10 MeV
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Fake-rate estimation
Given the two poissonian single-rates:
LVD = 0.1 Hz
OPERA = 0.06 Hz
the fake rate into a = 1s time window isfake = LVD OPERA~ 10-8 Hz
In a run period T=5 months the background is therefore
Nbg = fakeT = 0.1 events
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Time corrections for OPERA and LVD
OPERA: tevent = tclock + tfiber + telec
tfiber + telec= 45238.6 ns
LVD: tevent = tclock + tfiber (i) - telec
tfiber (1) = 42116.5 ns (Tower 1)
tfiber (2) = 42063.8 ns (Tower 2)
tfiber (3) = 42040.6 ns (Tower 3)
telec = 350 ns
N.B. tclock is in common (it’s the time stamp freezed before the transmission)
Procedure to find tclock
In OPERA, loop on the timeStamps of the digit’s events and find the minimum value 10 ns granularity different from the event timeStamp in *_filter.root files,
freezed at the beginning of the corresponding DAQ cicle In LVD, timeStamp of the first fired tank Each event is tagged beam event if its timeStamp is
within the spill start ±20 s (both in OPERA and in LVD) N.B. In the *_filter.root files, this
is not true: BEAM = spill start ±1 ms
Coincidence study: results
t<1ms
t<15 s
Beam events (intra-spill coincidences)
Triangular function between ±10.5 s well centered around zero: nice independent check of timing inter-calibration!
Beam events (intra-spill coincidences)
3 events with t<100 ns (within timing resolution): events generated by the SAME neutrino?(e.g. large angle di-muonevents)
Under investigation the possibility to study someexperimental handles(e.g. slopes on the XZ plane in both detectors to look for vertexing)
Cosmic events in coincidence
38 events peaked at ~ -573 ns!Explanation (confirmed by visual inspection): all events coming from the “Teramo valley” sticking OPERA first and LVD after.Distance measured by ToF: 573ns*0.3m/ns=172m(Expectations: dmin:dmax=170m:176m dtmin:dtmax= -587ns:-567ns)
LVD OPERA
Zenith-Azimuth mapTeramo ValleyBeam events
One of these 38 events: LVD view
One of these 38 events: OPERA view
Conclusions and plans A first analysis has been carried out on 2008 data
Found 145 beam events in coincidence (intra-spill) Useful to cross check data and timing intercalibration Extend the analysis to look for (or exclude) events generated
by the same neutrino interaction 38 cosmic events in coincidence
All coming from the Teramo valley Still to recognise their multiplicity: same muon or double
muon? Track reconstruction in YX view! Extend the analysis to include older data (outside run period)
Monte Carlo prediction using a QCD-inspired code (e.g. DPMJET): production ready to start with FLUKA (parameterized generators in this case are useless)
Atmospheric muon spectrum and charge ratio(N. Mauri and M. S.)
News with respect to the last meeting: Main bottleneck (HPT alignment) definitively solved, at
least for the purpose of this analysis (see later) Unfolding procedure Systematic error evaluation
Paper on cosmic rays restarted: Within April, a first draft version will be circulated and
discussed within the WG
Relative alignment between HPT stations
Start correcting in DX and DZ intra-doublet (magnet on) Iterate the procedure until it converges Correct for rotations intra-doublet Check for bumping Correct for rotations between doublets (magnet off) Final check plotting R vs
Starting situation
(From the work of Christoph, Irisha and Dima)
Results after 3 iterations
New shifts on x and z
X correction (cm)
Z correction (cm)
Plane2_SM1 0.031 0.441
Plane4_SM1 0.008 0.491
Plane6_SM1 0.047 0.447
Plane2_SM2 0.018 0.446
Plane4_SM2 0.121 0.310
Plane6_SM2 0.047 0.225
Corrections (in cm) we applied to the x and z shifts in the Alignment files in OpUtils/v*/data/DriftTube/Alignment
Study of the rotations intra-station (magnet on) VALUE ERROR
HPT 1-2 SM1 1 a_zy -1.47625e-04 3.59046e-03 2 a_xz 3.36670e-05 2.80332e-03 3 a_xy 7.42502e-06 5.31426e-03
HPT 3-4 SM1 1 a_zy 7.00820e-05 3.24239e-03 2 a_xz 1.19035e-04 2.53571e-03 3 a_xy 7.93161e-05 4.96220e-03
HPT 5-6 SM1 1 a_zy 5.90508e-05 3.86746e-03 2 a_xz -2.85497e-05 2.91879e-03 3 a_xy -6.74481e-05 5.53176e-03
HPT 1-2 SM2 1 a_zy -1.83383e-04 3.26790e-03 2 a_xz 1.27684e-06 2.54575e-03 3 a_xy 2.87309e-04 5.05467e-03
HPT 3-4 SM2 1 a_zy -5.89939e-06 3.52798e-03 2 a_xz -2.07120e-04 2.77148e-03 3 a_xy -9.40481e-05 5.64860e-03
HPT 5-6 SM2 1 a_zy 3.93602e-04 6.07937e-03 2 a_xz 1.37789e-04 4.30017e-03 3 a_xy 8.21664e-06 9.34348e-03
Study of the rotations between stations (magnet off)
VALUE ERROR
1 arm SM1
1 a_zy -3.89791e-04 1.79461e-02 2 a_xz 8.46438e-06 1.41929e-02 3 a_xy 1.19200e-04 2.01941e-02
2 arm SM1 1 a_zy -8.77744e-05 1.45676e-02 2 a_xz 1.19218e-04 1.10185e-02 3 a_xy 3.94737e-04 1.88165e-02
VALUE ERROR
1 arm SM2
1 a_zy -3.69397e-04 1.93282e-02 2 a_xz -1.82379e-04 1.53938e-02 3 a_xy 1.58743e-04 2.34608e-02
2 arm SM2 1 a_zy 1.57396e-04 1.82462e-02 2 a_xz 3.34168e-04 1.36295e-02 3 a_xy -3.78349e-05 2.20552e-02
Study of bending intra-station
DF within 1 mrad, mostly fluctuating randomlyDifficult to correct: insert in the systematic evaluationSome exceptions:
Results of the alignment
MAGNET OFFlivetime REAL = 13.635417 days
rate REAL spectro = 359.138275 events/day
doppietto 0cr real = 0.938534 +/- 0.046374 doppietto 1cr real = 1.045012 +/- 0.050989 doppietto 2cr real = 1.085923 +/- 0.064351 doppietto 3cr real = 1.013624 +/- 0.052733
entries 1 : 120.275; entries 2 : 123.282; entries 3 : 83.6791; entries 4 : 108.394
MAGNET ONlivetime REAL = 113.423752 days
rate REAL = 2326.117733 events/day
rate REAL spectro = 360.444787 events/day
doppietto 0cr real = 1.294306 +/- 0.021576 doppietto 1cr real = 1.356918 +/- 0.022803 doppietto 2cr real = 1.253912 +/- 0.025922 doppietto 3 cr real = 1.340062 +/- 0.025571
entries 1 : 129.03; entries 2 : 127.814; entries 3 : 83.5811; entries 4 : 98.9485
CR stability as a function of data taking
Event number
Beam muons: cross check of the analysis
Charge mis-Id: 4/215 eventsCharge mis-Id: 4/215 events
Charge/momentum unfolding
Standard method: matrix inversion
Log(1/p)
rate MC spectro = 783.833374 events/dayrate REAL spectro = 462.980630 events/day ratio REAL/MC spectro = 0.590662Misidentification probabilities:epp = 0.943793epm = 0.056207emp = 0.059502emm = 0.940498err epp = 0.013053err epm = 0.013053err emp = 0.015705err emm = 0.015705Average Misidentification probabilityeta media = 0.057596err eta media = 0.001833cr mc truth = 1.372291 +/- 0.021870cr mc = 1.331156 +/- 0.021166cr mc unf = 1.372249 +/- 0.021166cr real = 1.343745 +/- 0.014359cr real unf = 1.397389 +/- 0.017094
= 1.397 ± 0.017
)1(RR1
Rmeasured
measuredunfolded
Charge/momentum unfolding
More refined methods: Bayes and SVD + regularizations
Check on MC simulation (Bayes method on q/p)
Charge/momentum unfolding
More refined methods: Bayes and SVD + regularizations
q/p Bayes
q/p SVD
Charge/momentum unfolding
More refined methods: Bayes and SVD + regularizations
Cos Bayes
Rock Bayes