CAL Resolutions for LC Detectors

1
CAL Resolutions for LC Detectors
S. Magill
SiD W/Si ECAL -gt ECAL resolution for photons
GEANT4 Simulation SiD SS/RPC HCAL -gt neutral
hadron resolution (n, KL0) SDFeb05
W/Scintillator HCAL -gt neutral resolution (n,
KL0) SDFeb05 W/RPC HCAL -gt neutral resolution
(KL0) Perfect PFA Results -gt comparison of
detector calorimeters Evaluations
2
SiD W/Si ECAL
20/?E
Sf 0.0121
10 GeV Photons
1,2,5,10,20 GeV Photons
Fit results 19.6/?E ? 1.45
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SiD SS/RPC HCAL
Hits for 2,5,10,20 GeV Neutrals 2
GeV 5 GeV 10 GeV 20 GeV Mean 8.6
33.7 75.3 144.3 ? 5.6
12.2 22.4 41.5 ?/mean 0.65
0.36 0.30 0.29 -gt Fit Result
76/?E ? 21 !
10 GeV n
94/?E !!
2,5,10,20 GeV KL0, n
No threshold cut on hits
Average 6.5 hits/GeV
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SDFeb05 W/Scin HCAL
Hits for 2,5,10,20 GeV Neutrals 2
GeV 5 GeV 10 GeV 20 GeV Mean 18.6
56.8 126.9 253.5 ? 7.7
15.2 26.6 41.3 ?/mean 0.41
0.27 0.21 0.16 -gt Fit Result
56/?E ? 11
5 GeV n
58/?E
5 GeV n
2,5,10,20 GeV KL0, n
51/?E
1/3 mip threshold cut on hits
Average 11.5 thr hits/GeV
No threshold cut
5
SDFeb05 W/RPC HCAL
Hits for 2,5,10,20 GeV Neutrals 2
GeV 5 GeV 10 GeV 20 GeV Mean 14.1
41.8 85.4 154.8 ? 6.4
13.6 19.6 43.3 ?/mean 0.45
0.33 0.23 0.28 -gt Fit Result
54/?E ? 21
2,5,10,20 GeV KL0
No threshold cut on hits
Average 7.9 hits/GeV
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Fit Results for HCAL Resolutions
Fit results SDFeb05 W/Scin 56/?E ?
11 SDFeb05 W/Scin 56/?E ? 3 SDFeb05 W/RPC
54/?E ? 21 SiD SS/RPC 76/?E ? 21
?/E
?/?E ()
E (GeV)
SS/RPC
Questions? 1) Shape of RPC results? 2) What is
the source of the large constant term for the
RPCs? 3) Perfect PFA results? 4) RPC detector
improvements?
W/RPC
W/Scin
E (GeV)
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Perfect PFA Results

• In ZPole events, neutral E Sum 11 GeV
• -gt contribution to PFA from neutrals for perfect
  PFA ? E ? ((X/?E)2 Y2) X fractional
  stochastic term, Y fractional constant term
• SDFeb05 W/Scin ? 2.2 GeV from
  neutrals
• -gt 26/?E Total Perfect PFA (with 1 GeV from
  photons) 28/?E in ZPole events
• SDFeb05 W/RPC ? 2.9 GeV from
  neutrals
• -gt 32/?E Total Perfect PFA 32/?E in ZPole
  events
• SiD SS/RPC ? 3.4 GeV from
  neutrals !
• -gt 37/?E Total Perfect PFA
• -gt Total ? 3.54 -- No champagne for this
  detector!

SiD HCAL includes worst combination of absorber
and active media -gt Cant reach PFA goal -gt Poor
detector for PFA development?
SiD HCAL
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RPC Detector Improvements?
1) Use SS as absorber, but decrease ?I per layer
to get better sampling 2 cm SS -gt 1 cm SS (.12 ?I
-gt .06 ?I) But . . . Needs 68 layers to keep 4
?I depth of HCAL So, HCAL IR -gt OR goes from 95.2
cm to 122.4 cm (30 increase) 2) Use W as
absorber, but thinner than SDFeb05 example, e.g.
0.5 cm W (.05 ?I) Needs 77 layers, so HCAL IR -gt
OR is 100 cm Is resolution good enough?
RPC improvements push HCAL OR out -gt RPC better
suited for large detector? LDC?, GLC?
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Compact Detector HCAL Design

• A compact detector calorimeter should have
• Dense absorber
• Solid (or liquid?) readout medium

Example 0.6 cm W, 0.5 cm Scintillator, 0.1 cm
gap 64 layers, 1.2 cm per layer HCAL IR -gt OR 77
cm (20 decrease in OR of HCAL)