Performance Goals -> Motivation

Analog/Digital Comparisons

E-flow Algorithm Development

Readout R&D

Summary

Optimization of the Hadron Calorimeter Optimization of the Hadron Calorimeter for Energy-Flow Jet Reconstructionfor Energy-Flow Jet Reconstruction

Stephen R. Magill

Argonne National Laboratory

Performance Goals for HCAL - Performance Goals for HCAL - MotivationMotivation

Physics Requirement : separately id W, Z using dijet mass in hadronic decay mode (~70% BR) -> higher statistics physics analyses

Detector Goal : measure jets with energy resolution /E ~ 30%/E

Optimize HCAL to be used with ECAL andTracker in E-flow jet reconstruction –

• Charged particles ~ 60% of jet energy -> Tracker• Photons ~ 25% of jet energy -> ECAL• Neutral Hadrons ~ 15% of jet energy -> HCAL

Calorimeter challenge : charged/neutral showerseparation requires high granularity, bothtransverse and longitudinal, to reconstruct showers in 3-D

W, Z

30%/30%/EE

75%/75%/EE

HCAL Optimization Performance HCAL Optimization Performance MeasuresMeasures

• Study absorber type/thickness with JAS, standalone GEANT3 program-> shower containment, hit density, single particle energy resolution

• Tune transverse granularity and longitudinal segmentation in JAS-> separation of charged/neutral hadron showers

• Test both analog and digital readout techniques-> comparison of energy/hit density readout methods

• Develop and optimize E-flow algorithm(s)-> dijet mass resolution

TungstenCopper

Uranium

SS

4 ’s, 2 K0L, +, -

Standalone GEANT3 VersionStandalone GEANT3 Version

TESLA TDR Detector Geometry

e+e- ZZ (500 GeV CM)

SD Detector :

ECAL HCAL 30 layers 34 layers W(0.25 cm)/Si(0.04 cm) SS(2.0 cm)/Scin(1.0 cm) ~20 X0, 0.8 I ~40 X0, 4 I ~5 mm X 5 mm cells ~1 cm X 1 cm cells

Modified SD A:

ECAL30 layers W(0.25 cm)/Si(0.04 cm)~20 X0, 0.8 I ~1 cm X 1 cm cells

HCAL60 layersW(0.7 cm)/Scin(1.0 cm)~120 X0, 4.5 I ~1 cm X 1 cm cells

Modified SD B:

ECAL30 layers W(0.25 cm)/Si(0.04 cm)~20 X0, 0.8 I ~1 cm X 1 cm cells

HCAL60 layersW(0.7 cm)/Scin(1.0 cm)~120 X0, 4.5 I ~3 cm X 3 cm cells

Java Analysis Studio (JAS)Java Analysis Studio (JAS)

Modified SD C:

ECAL30 layers W(0.25 cm)/Si(0.04 cm)~20 X0, 0.8 I ~1 cm X 1 cm cells

HCAL60 layersW(0.7 cm)/Scin(1.0 cm)~120 X0, 4.5 I ~5 cm X 5 cm cells

Neutral particles in CAL - in ECAL- KL

0, n, nbar in HCAL

ee++ee-- -> ZZ – Neutral Particles in CAL -> ZZ – Neutral Particles in CAL

Analog Readout – perfect cluster

Photon Analysis in SD – Analog vs Digital?Photon Analysis in SD – Analog vs Digital?

/mean ~ 16%/mean ~ 16%

5 mm X 5 mm EM cells

Non-linear behaviorNon-linear behaviorfor dense showersfor dense showers

Analog EMCAL ReadoutAnalog EMCAL Readout

Neutral Hadron Analysis – Analog vs Neutral Hadron Analysis – Analog vs DigitalDigital

KKLL00 Analysis – SD Detector Analysis – SD Detector

Analog ReadoutAnalog Readout

/mean ~ 30%

Compare to digital

KKLL00 Analysis – SD Detector Analysis – SD Detector

Digital ReadoutDigital Readout

/mean ~ 26%

Average : ~43 MeV/hit

linear behavior forhadron showers

Analog EM + Digital HAD x calibration

KKLL00 Analysis – Modified SD Analysis – Modified SD Analog ReadoutAnalog Readout

SD A (1 cm X 1 cm)

SD B (3 cm X 3 cm)

/mean ~ 26%

/mean ~ 35%

KKLL00 Analysis – Modified SD Analysis – Modified SD Digital ReadoutDigital Readout

SD A (1 cm X 1 cm)

SD B (3 cm X 3 cm)

/mean ~ 20%

/mean ~ 25%

HCAL (only) Digital HCAL (only) Digital ResultsResults

/mean ~ 28%

/mean ~ 28%

/mean ~ 32%

SD

SD A

SD B

1 cm X 1 cm

1 cm X 1 cm

3 cm X 3 cm

KKLL00 Analog vs Digital – Scintillator vs Gas Analog vs Digital – Scintillator vs Gas

From A. Sokolov, CALICE

Scintillator Analog/DigitalScintillator Analog/Digital

Scintillator Analog/RPC DigitalScintillator Analog/RPC Digital

Compensation in Digital HCAL?Compensation in Digital HCAL?

Neutral Hadron Measurement SummaryNeutral Hadron Measurement Summary

No-Clustering E-Flow AlgorithmNo-Clustering E-Flow Algorithm

1st step - Track extrapolation thru Cal – substitute for Cal cells in road (core + tuned outlyers) – Cal granularity optimized for separation of charged/neutral clusters

2nd step - Photon finder (use analytic long./trans. energy profiles)

3rd step - Jet Algorithm on Tracks and Photons

4th step – include remaining Cal cells in jet (cone?)

Systematic Approach : Tracks first (60%), Photons next (25%),Neutral hadrons last (15%)

Track Extrapolation/Cal Cell SubstitutionTrack Extrapolation/Cal Cell Substitution

Starting studies of HCAL optimization for E-Flow jet analysis- optimal transverse cell size and longitudinal segmentation- optimal absorber material/thickness- analog vs digital readout

Starting development of E-Flow analysis tools- Track extrapolation -> cal cell substitution analysis - photon analysis

Beginning readout R&D-Scintillator in HCAL-RPC

SummarySummary