Large Magnetic Calorimeters Anselmo Cervera Villanueva University of Geneva (Switzerland) in a...

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





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





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






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






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




BB BB

beam EEhad

1.104.10


EEhad

1217


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






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


Good charge identificationGood charge identification

Good hadron backgrounds rejectionGood hadron backgrounds rejection

Reasonable Cost Reasonable Cost

Anselmo Cervera VillanuevaUniversity of Geneva

(Switzerland)

Large Magnetic Calorimeters Anselmo Cervera Villanueva University of Geneva (Switzerland) in a...

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