Testbeam Requirements for LC CalorimetryTestbeam Requirements for LC Calorimetry

S. R. Magill for theCalorimetry Working Group

Physics/Detector Goals for LC Calorimetry

E-flow implications for CAL Design/Testing

Optimization for E-flow Testbeam Goals

Hardware/Readout mode tests

E-flow/Detector simulation validation/verification

Test Beam Programs and Venues

Summary

Physics/Detector Goals for LC CalorimetryPhysics/Detector Goals for LC Calorimetry

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

Detector Goal : measure jets with energyresolution -> -> /E ~ 30%//E ~ 30%/EE

Calorimeter challenge : match tracksto charged hadrons – requires separationof charged/neutral hadron showers in Cal,and isolation of photons –> E-flow approach

-> high granularity, both transverse and -> high granularity, both transverse and longitudinal, to reconstruct showers in 3-Dlongitudinal, to reconstruct showers in 3-D

W, Z

30%/M

75%/M

For example, explore EWSB thru the interactions : e+e- -> WW and e+e- -> ZZ

-> Requires Z,W ID-> Can’t always use (traditional) constrained fits

E-Flow Implications for CalorimetryE-Flow Implications for Calorimetry

Traditional Standards

HermeticityUniformity

CompensationSingle Particle E measurementOutside “thin” magnet (~1 T)

E-Flow Modification

HermeticityOptimize ECAL/HCAL

separatelyLongitudinal Segmentation

Particle shower reconstruction

Inside “thick” coil (~4 T)Optimized for best single particle E resolution

Optimized for best particle shower separation/reconstruction

ECAL E-flow ECAL E-flow OptimizationOptimization

For good isolation of photon showers :-> small rM (Moliere radius) – dense calorimeter-> If the transverse segmentation is of size rM, get optimal transverse separation of electromagnetic clusters-> If X0/I is small, then the longitudinal separation between starting points of electromagnetic and hadronic showers is large

All of the above help to separate hadron showers as wellSome examples :Material Z A X0/I

Fe 26 56 0.0133Cu 29 64 0.0106W 74 184 0.0019Pb 82 207 0.0029U 92 238 0.0016

Priorities :1) Measure (isolated) photon energy2) Separate charged/neutral hadron showers

A dense ECAL with high granularity (small transverse size cells), high segmentation (many thin absorber layers), and with X0/I small is optimal for E-Flow.

-> 3-D shower reconstruction

HCAL E-flow OptimizationHCAL E-flow Optimization

To optimize the HCAL for E-Flow requires : full containment of (neutral) hadronic showers good precision on energy measurement high segmentation in transverse and longitudinal directions inorder to separate in 3-D close-by clusters in jets

Integrated approach including other detector sub-components in the design phase, with E-Flow algorithms

Assume a tracking system optimized for, e.g., di-leptonmeasurements Assume a dense ECAL optimized for photon reconstruction Vary HCAL parameters, e.g., absorber material, thickness, size ofreadout cells in both transverse and longitudinal directions, to determine optimal performance in an E-Flow Algorithm.

Priorities :1) Measure neutral hadron energy2) Separate charged/neutral hadron showers

Testbeam Goals for CalorimetryTestbeam Goals for Calorimetry

Test detector hardware technologies and readout configurations

-> flexible configurations of absorber type and thickness, active media types-> linearity, uniformity, signal response, energy resolution, analog/digital readout schemes

Study reconstruction algorithms-> flexible configurations of transverse granularity, longitudinal segmentation-> E-flow properties, particle shower shapes-> beam particle tracking?

Validate/verify MC simulation-> shower libraries

Calorimeter Hardware/Readout Calorimeter Hardware/Readout SchemesSchemes

ECAL

Si pixel/W sandwich Analog “SD Detector”Scin Tile/W sandwich Analog Si-Scin/W hybrid AnalogDense Crystals AnalogCerenkov compensated AnalogHCAL

Scin Tile/SS sandwich Analog “CALICE”Scin “pixels”/SS DigitalRPC/SS DigitalGEM/SS Digital

Same absorber – hanging file configuration at Testbeam?

E-flow/Simulation validation Testbeam E-flow/Simulation validation Testbeam RequirementsRequirements

Design of CAL relies on simulation for E-flow algorithm applications

Simulations need to be verified in testbeam at particle shower level

Ultimate goal is jet energy/particle mass resolution - not possible in test beam

So, since EFAs require separation/id of photons, charged hadrons, and neutrals -

Verify photon shower shape in ECAL prototype (Si/W with fine granularity - 1X1 cm**2 or better – see plot)

Verify pion shower probability in ECAL as function of longitudinal layer

Verify pion shower shapes in ECAL/HCAL prototype (must be able to contain the hadron shower both transverse and longitudinally – see plot)

Try to get beams with particle energies as in Z jets from e+e- -> ZZ at 500 GeV ->

e+e- -> ZZ @ 500 GeVe+e- -> ZZ @ 500 GeV

Energy (GeV) Energy (GeV) Energy (GeV)

3 GeV e- in SD Cal3 GeV e- in SD Cal

LayerSh

ow

er

Rad

ius

(bla

ck)

Am

pl. F

ract

ion

(re

d)

70% of e- energy in layers 3-9

2.6,3.1

13,15.5

5.2,6.2

cm(front,back)

ECAL

ECAL/HCAL Boundary

10 GeV 10 GeV -- in SD Cal in SD Cal

Need all 34 layers

20 cm X 20 cm X 30 layer ECAL

80 cm X 80 cm (min.) X 34 layer HCAL

Sh

ow

er

Rad

ius

(red

) A

mp

l. F

ract

ion

(b

lue)

3.1,5.2

7.8,12.6

15.5,26

cm(front,back)

HCAL

Summary of SD Calorimeter Properties Summary of SD Calorimeter Properties On average, 94% of pion energy is contained within an ECAL area of 20 X 20 cm2

-> 20% of 10 GeV pions appear as MIPS throughout the entire ECAL volume, therefore are 100% contained

In the SD CAL, 95% of pion energy is contained for 35% of 10 GeV pions in a 20 X 20 cm2 ECAL coupled with an 80 X 80 cm2 HCAL (90% containment for 66% of these pions)

-> important to tag leakage from ECAL/HCAL in all directions

In a digital SD HCAL, 90% of pion hits are contained in a 90 X 90 cm2 area

-> again, important to tag leakage from ECAL/HCAL in all directions

Readout Channels for Testbeam CAL :30 X 30 cm2 SD ECAL (0.5 cm X 0.5 cm pixels in 30 layers)

-> 108K channels!!!1 X 1 m2 SD HCAL (1 cm X 1 cm cells in 40 layers)

-> 400K channels!!!

Tagging scintillator paddles surround CAL modules

HCAL

ECAL

Beam halo veto scintillator paddles

Beam

Wire Chambers (3-views)

Scintillator hodoscopes

Dead material

LC CAL Testbeam ConfigurationLC CAL Testbeam Configuration

HCAL : 1 X 1 X 1 m3

Testbeam ProgramsTestbeam Programs

Several scenarios suggested so far :

Testbeam requirements :a. Electron and photon beamb. Pion and other hadron beamc. Energies of EM and Hadrons: 5 - 150 ~ 250 GeV (If possible as low energies as possible, down to 1~2 GeV)d. Muon beam at energies 1-100 GeV or so --> This is for calorimeter tracking algorithm studies.

Testbeam VenuesTestbeam Venues

SummarySummary

The Calorimeter Working Group has begun to think about testbeam programs – first working document written which addresses :

-> Compatibility of various hardware configurations in the same testbeam area-> Challenge of testbeam programs for E-flow calorimetry-> Challenge of several readout configurations, large number of channels-> First look at possible venues-> Cooperation with European (CALICE) colleagues