Large MagneticLarge Magnetic
CalorimetersCalorimeters
Anselmo Cervera Villanueva
University of Geneva(Switzerland)
in a Nufactin a Nufact
Nufact04(Osaka, 1/8/2004)
2
Aim of the talkAim of the talk
Present the 2 studies Present the 2 studies in the market in the market
Combine them Combine them because they are because they are
complementarycomplementary
Demonstrate that Demonstrate that the technique worksthe technique works
LMD (Large Magnetic Detector)
Monolith
BB BB
Monolith:Monolith: detector resolution
LMD:LMD: background studies
known technology (MINOS)
10 x MINOS
3
Studies in the marketStudies in the market
Fast simulation and reconstruction based on MINOS smearing
Muon identification Charge identification Study of background rejection power
and efficiencies Variation of smearing parameters
BB BB
MonolithMonolith LMDLMD
M. SelviM. SelviM. Garbini M. Garbini H. MenghettiH. Menghetti
A. CerveraA. CerveraF. DydakF. DydakJ.J. Gomez-CadenasJ.J. Gomez-Cadenas
Full simulation and reconstruction
Careful study of the hadronic angular resolution, including test beam
Charge identification
4
wrongwrongsignsign
muonmuon
Stored +
not detected
D
e
charge misidentified
ee
De e
Charge misidentification
BackgroundsBackgrounds
NC
CC
Hadron decay
e
e
e
50%
50%
in the final state
no other lepton
‘‘Golden’ signature : wrong sign muons Golden’ signature : wrong sign muons detectordetector
5
Detector requirementsDetector requirements
P
Ehad
had
Large statistics Large mass: ~40 KTons~40 KTons Muon identification: from rangefrom range Charge identification: B~1 TeslaB~1 Tesla Kinematic quantities (for background rejection)
From the muon: 3-momentum3-momentum Hadron shower: energy and angleenergy and angle
1. Reasonable number of spatial measurements: every ~5-10 cmevery ~5-10 cm 2. Reasonable transverse resolution: ~1 cm~1 cm
6
ChallengesChallenges
Good Muon identificationGood Muon identification
Large massLarge mass
Good Charge identificationGood Charge identification
Good Hadron background rejectionGood Hadron background rejection
Low CostLow Cost
7
The MONOLITH DetectorThe MONOLITH Detector
Large mass ~ 35 ktonMagnetized Fe spectrometer B = 1.3 Tesla (toroidal)Space resolution ~ 1 cm (3cm pitch in x and y) Time resolution ~ 1 ns (for up/down discrimination)Momentum resolution (p/p) ~ 20% from track curvature for outgoing muons ~ 6% from range for stopping muons
Hadron E resolution (Eh /Eh) ~ 90%/Eh 30%
30 m
13.1 m
14.5 m
8 cm
2.2 cm
Fe
Fe
B BGlass Spark Counters
(RPC’s with glass electrodes
beam
8
The Large Magnetic DetectorThe Large Magnetic Detector
Geant3 simulation: Multiple scattering and energy loss Decays Nuclear interactions
Full reconstruction is not practical since one has to simulate ~107 events for each setting Smearing according to the MINOS proposal
Conceptual design Simulation
iron (4 cm) scintillators (1cm)
beam
20 m
10 m
10 m
B=1 T
1cm transverse resolution
9
ChallengesChallenges
Good Muon identificationGood Muon identification
Large massLarge mass
Good Charge identificationGood Charge identification
Good Hadron background rejectionGood Hadron background rejection
Low CostLow Cost
10
Massive detectorMassive detector
30 m
5.4 KT5.4 KT
40 KT40 KT
fully operational fully operational since July 2003since July 2003
MINOSMINOS
11
ChallengesChallenges
Good Muon identificationGood Muon identification
Large massLarge mass
Good Charge identificationGood Charge identification
Good Hadron backgrounds rejectionGood Hadron backgrounds rejection
Low CostLow Cost
12
Muon identificationMuon identification
At these energies, muons can be easily identified by range
Length traveled by the longest pion/kaon Length versus muon momentum
LMDLMD
stored 50 GeV/c stored 50 GeV/c ++
13
ChallengesChallenges
Good Muon identificationGood Muon identification
Large massLarge mass
Good Charge identificationGood Charge identification
Good Hadron backgrounds rejectionGood Hadron backgrounds rejection
Low CostLow Cost
14
Charge in MonolithCharge in Monolith
Selection cuts:
• P (from range) > 7.5 GeV
• In each region:• At least 4 points• Track length > 300 cm
• Same charge assigned in each region
Fractional bkg.Fractional bkg.1 x 101 x 10-6-6
Efficiency Efficiency 35%35%
top
vie
wsi
de
vie
wMonolithMonolith
Multiple scattering and Energy lossMultiple scattering and Energy lossKalman filter fitKalman filter fit
15
Charge in LMDCharge in LMD
transverse transverse resolutionresolution
distance distance between between
planesplanes
percentage percentage of lost hitsof lost hits
25cm15
5
20%
1%
2 cm
0.5 cm
100
10
4050% efficiency
LMDLMD
Multiple scattering and Energy lossMultiple scattering and Energy lossKalman filter fitKalman filter fit
parallel-8cmparallel-8cm
normal-15cmnormal-15cm
LMDLMD
MonolithMonolith
Conclusion:Conclusion:1010-6 -6 effecteffect
cha
rge
mis
ide
ntifi
catio
n
bkg
cha
rge
mis
ide
ntifi
catio
n
bkg
16
ChallengesChallenges
Good Muon identificationGood Muon identification
Large massLarge mass
Good Charge identificationGood Charge identification
Good Hadron backgrounds rejectionGood Hadron backgrounds rejection
Low CostLow Cost
17
Hadronic backgroundsHadronic backgrounds
Kinematic analysisMC reconstructed variables: pp,,had had , , hadhadVariables used in the analysis
P
hadron-jet
LMDLMD
P
Qt=Psin2
Philosophy “Real” wrong sign muons are harderAnd are more isolated from the hadronic jet
P
tQ
18
Hadronic angular resolutionHadronic angular resolution
EEhad
15.1267.16
EEhad
2.832
EEhad
1223
EEhad
1215
Minos/LMDMinos/LMD
parallel-8cmparallel-8cm
parallel-4cmparallel-4cm
normal-8cmnormal-8cm
BB BB
beam EEhad
1.104.10
normal-10cmnormal-10cm
EEhad
1217
normal-5cmnormal-5cm
Iron (5cm) + RPC (2cm) Iron (5cm) + RPC (2cm)
Monte CarloMonte Carlo Data (Test Beam)Data (Test Beam)
(Monolith proposal)
MonolithMonolith
19
CC interactionsCC interactionsnot detected
D
LMDLMD
20
eeCC interactionsCC interactions Assuming no electron id
identified as pion or not detected
De
e
LMDLMD
21
((ee) ) NCNCinteractionsinteractions
De
e
LMDLMD
22
Sensitivity to Sensitivity to
Baseline P cut Qt cutsignal
eff
CC(x10-7)
eCC(x10-7)
(e) NC(x10-7)
surviving
signal &
background
732 5.0 1.4 0.24 11 1 250005000
50
3500 5.0 0.7 0.45 54 1 233000030000
10
7300 5.0 0.6 0.52 74 1 3080008000
2
LMDLMD
10102121 useful 50 GeV/c useful 50 GeV/c + + decaysdecays
o
o
m
8
45
108.2
13
1223
3223
732 Km
3500 Km
23
ChallengesChallenges
Good Muon identificationGood Muon identification
Large massLarge mass
Good Charge identificationGood Charge identification
Good Hadron backgrounds rejectionGood Hadron backgrounds rejection
Low CostLow Cost
24
Naive Cost estimateNaive Cost estimate
cost ~ 5-10 x MINOScost ~ 5-10 x MINOS
30 m
known technologyknown technology
working detectorworking detector
scintillator module
extruded polystyrene scintillator
multi-pixel PMTs
25
CONCLUSIONS
CONCLUSIONSChallengesChallenges
Good muon identificationGood muon identification
Large massLarge mass
Good charge identificationGood charge identification
Good hadron backgrounds rejectionGood hadron backgrounds rejection
Reasonable Cost Reasonable Cost
Anselmo Cervera VillanuevaUniversity of Geneva
(Switzerland)