j-c brient prague 2002 1 performances studies of the calorimeter/muon det. e + e – w + w – at ...

1J-C BRIENTPrague 2002Prague 2002

Performances studies of the calorimeter/muon det.

e+e– W+W– at s=800 GeV Simulation SLAC-Gismo

Simulation MOKKA-GEANT4Visualisation FANAL CALICECALICE

The paradigm in 2002 : the jet reconstruction is the key point


jet(s) or di-jet ?

zoom

e+e‒W+W– à s=800 GeV

Calorimeter jet view

View for W-Si ECAL and Digital HCAL


2 jet = 2ch. + 2 + 2 h0 ++ ++

dominant contributionsdominant contributions For a track momentum resolution about ~10-5 An ECAL energy resolution ~ 12% ( (stochastic term)An HCAL energy resolution ~ 45% ( (stochastic term)On a

2jet ~ (0.14)2 Ejet + 2

confusion + 2threshold

2confusion

The strategyThe strategyThe strategyThe strategy

Individual reconstruction of each particle by topology (Bubbles chamber)

The level of confusion between particle The level of confusion between particle determine the quality of the reconstructiondetermine the quality of the reconstruction

Impr

oper

ly c

alle

d E

nerg

y Fl

ow

EEjetjet = = Echarged track ++ E ++ Eh0

fraction fraction 65% 26% 9%

A typical jet

Large multiplicityof low/medium energy

particles

No confusionNo threshold ⇒∼0.14

2threshold

Adapted from

Dean K

arlen


The minimisation of the confusion contribution leads to ① A strong magnetic field and a large internal radius of the

calorimeter ⇨ Help for the separation charged /neutral

② A small Molière radius ⇨ Minimise the overlap between close showers

③ A maximisation of the longitudinal segmentation (vision in 3D)(vision in 3D)

⇨ Allows a better separation between close showers

④ to have both ECAL and HCAL inside the coil and minimise the dead zone

⑤ The development of 3D reconstruction algorithm

And for the threshold ⑥ A good S/N at low energy

Choice in ECFA groupsChoice in ECFA groups,, choice in LCD-US choice in LCD-US groupsgroupsACFA choice is differentACFA choice is different

e/h=1 and some precise layers


ECAL : Sampling tungsten-silicon

Sampling radiator-tile

HCAL : Sampling radiator-scintillator tiles

Sampling radiator-gas detector

n

CALICE CALICE W-Si Rint~170 Pad 1x1 cm

SD-LCD W-Si Rint~120 (SLAC-Oregon) Pad 0.5x0.5cm

LCCAL 5x5cm tiles (Italian labs) 3 silicon layers

ACFA choice 4x4cm tiles 2 layers fibers

Staggered tile Rint~160 (Uni. Colorado) tile 5x5cm

CALICE CALICE tile-HCALtile-HCAL projective tiles 9 layers

CALICE CALICE DHCAL ( Pad 1x1cm 1bit-readout

40 layers

And some exotic proposals (crystal ECAL,…)


CALICE CALICE performances performances studies includestudies include Performance variation with dead wafers, with inter-calibration(Only ECAL), with pad size (DHCAL), perf. on jets with HCAL resolution, with variation of X0 in tungsten plates,…

Electronics readout performances,noise,etc…is included (ECAL only)

Performance with jets (at Z peak for both HCAL option)

Performance with jets at high energy (numerical values for tile HCAL)

Studies of DHCAL performance (single track) with radiator (steel, tungsten,…) , with pad size.

Electron, muon ID. for isolated particle/in jets (better than ALEPH…)

TO DOTO DO Almost everything

- performances with pad size, with layer numbers (partly done for ECAL)- performances at high energy (including boson mass) - input for the electronics (HCAL mainly)- input for Lumi. measurement (end-cap), input for TPC T0 calibration.…………


Impact from dead wafersImpact from non-uniformity (inter-calibration)

Response non-uniformity in ECAL (%) Fraction of dead wafers in ECAL (%)

CALICECALICE ECAL studies

J-C. B. J-C. B.

Only a small variation of the performanceswith imperfect construction/knowledgeof the device


Photon ID in jets

Jets at 91 GeV

ZH at 500 GeVZ in , H in jets

Electron ID

Hadron MISID

Particle momentum GeV

ALL VALUES in %

Photon energy GeV

Electron ID in jets

ECAL

/mean ~ 29%/mean ~ 29%

DHCAL 1 cm

X 1

cm

DHCAL 1 cm

X 1

cm

HCAL

S.Magill

ID

Jet mass

→

→and→new

250 GeV ±


Jet mass < 0.2

Jet mass in 0.2-2

→

82% 17%

→

2% 90%

Tau decays ID is essential for ID and polarisation measurement

(250 GeV) →

charged pion

Photons from oLooking alongthe ch. trackin 5-12 X0

Looking along the charged track in the first 4 X0


CALICE ECAL(W-Si) + DHCAL

Z at rest decaying in jets

CALICECALICE ECAL+HCAL studies

D.Orlando

V.Morgunov

CALICE ECAL(W-Si) + THCAL


Position resolution ~2mm

SD-LCDSD-LCD (M.Iwasaki, T.Abe,…)

Photons ID in jets Effic. ~85% Purity ~ 85%

Top mass measurement (no neutral hadron rec.)

Resolution on photon directionEtc…

Need a more complete/improved reconstruction

LCCALLCCAL (P.Checchia)

Single particle perf. electron/pion separation electron position resolution

Need simulationNeed reconstruction

50 GeVElectron

Test beam data

10 GeV photon from IP


CALICECALICE A lot of performances have been estimated on GEANT3-4 simulation It remains a lot to do – progress foreseen for next ECFA workshop

LCCALLCCAL single particle performance in TB , jets ??

SD-LCDSD-LCD Works started with full simulation, some results on jets events

ST-ECALST-ECAL** Works in progress

ACFA ACFA calorimeter group Works in progress, single particle performance in TB

Conclusion

* Staggered tiles ECAL in Colorado


What about muon outer system

A la TDR (Marcello Picollo). Simulation Geant4 with only a crude reconstruction.

It clearly need to be linked with the inner detector (inside the coil) Which number of layers ? What is the best location in the Yoke,…Which mode (Streamer , avalanche) , which level of occupancy acceptable ?Which readout ? Which performance in jets ? , etc…

RPC’sRPC’s

Proposed by G.Fisk. Could be very cheap !! But so far I don’t know about any simulation and/or performances study.

Scintillator basedScintillator based “a la MINOS”


0

0.2

0.4

0.6

0.8

1

0 10 20 30 40 50

Muon momentum GeV

Effi

cien

cy m

uon

ID

Isolated muon ID. (crude criteria)

- with 2D readout 1x1 cm - from FULL simulation GEANT4

Marcello in Jeju-do

Note the threshold due to the coil atAbout 6 GeV/c

j-c brient prague 2002 1 performances studies of the calorimeter/muon det. e + e – w + w – at ...

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