 Performance Goals -> Motivation  Analog/Digital Comparisons  E-flow Algorithm Development  Readout R&D  Summary Optimization of the Hadron Calorimeter for Energy-Flow Jet Reconstruction Stephen R. Magill Argonne National Laboratory

Performance Goals for HCAL - Motivation 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 and Tracker 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 shower separation requires high granularity, both transverse and longitudinal, to reconstruct showers in 3-D W, ZW, Z 30%/  E 75%/  E

HCAL Optimization Performance Measures 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 

Tungsten Copper Uranium SS 4  ’s, 2 K 0 L,  +,  - Standalone 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 X 0, 0.8 I ~40 X 0, 4 I ~5 mm X 5 mm cells ~1 cm X 1 cm cells Modified SD A: ECAL 30 layers W(0.25 cm)/Si(0.04 cm) ~20 X 0, 0.8 I ~1 cm X 1 cm cells HCAL 60 layers W(0.7 cm)/Scin(1.0 cm) ~120 X 0, 4.5 I ~1 cm X 1 cm cells Modified SD B: ECAL 30 layers W(0.25 cm)/Si(0.04 cm) ~20 X 0, 0.8 I ~1 cm X 1 cm cells HCAL 60 layers W(0.7 cm)/Scin(1.0 cm) ~120 X 0, 4.5 I ~3 cm X 3 cm cells Java Analysis Studio (JAS) Modified SD C: ECAL 30 layers W(0.25 cm)/Si(0.04 cm) ~20 X 0, 0.8 I ~1 cm X 1 cm cells HCAL 60 layers W(0.7 cm)/Scin(1.0 cm) ~120 X 0, 4.5 I ~5 cm X 5 cm cells

Neutral particles in CAL -  in ECAL - K L 0, n, nbar in HCAL e + e - -> ZZ – Neutral Particles in CAL

Analog Readout – perfect  cluster Photon Analysis in SD – Analog vs Digital?  /mean ~ 16% 5 mm X 5 mm EM cells Non-linear behavior for dense showers Analog EMCAL Readout

Neutral Hadron Analysis – Analog vs Digital

K L 0 Analysis – SD Detector Analog Readout Analog Readout  /mean ~ 30% Compare to digital 

K L 0 Analysis – SD Detector Digital Readout Digital Readout  /mean ~ 26% Average : ~43 MeV/hit linear behavior for hadron showers Analog EM + Digital HAD x calibration

K L 0 Analysis – Modified SD Analog Readout Analog Readout SD A (1 cm X 1 cm) SD B (3 cm X 3 cm)  /mean ~ 26%  /mean ~ 35%

K L 0 Analysis – Modified SD Digital Readout Digital Readout SD A (1 cm X 1 cm) SD B (3 cm X 3 cm)  /mean ~ 20%  /mean ~ 25%

HCAL (only) Digital Results  /mean ~ 28%  /mean ~ 32% SD SD A SD B 1 cm X 1 cm 3 cm X 3 cm

K L 0 Analog vs Digital – Scintillator vs Gas From A. Sokolov, CALICE Scintillator Analog/Digital Scintillator Analog/RPC Digital

Compensation in Digital HCAL?

Neutral Hadron Measurement Summary

No-Clustering E-Flow Algorithm 1 st step - Track extrapolation thru Cal – substitute for Cal cells in road (core + tuned outlyers) – Cal granularity optimized for separation of charged/neutral clusters 2 nd step - Photon finder (use analytic long./trans. energy profiles) 3 rd step - Jet Algorithm on Tracks and Photons 4 th step – include remaining Cal cells in jet (cone?) Systematic Approach : Tracks first (60%), Photons next (25%), Neutral hadrons last (15%)

Track 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 Summary