Документ взят из кэша поисковой машины. Адрес оригинального документа : http://zebu.uoregon.edu/~uochep/docs/docs01/cal_perform.pdf Дата изменения: Wed Oct 17 20:52:44 2001 Дата индексирования: Tue Oct 2 11:12:33 2012 Кодировка: Поисковые слова: m 80

LCD Calorimeter Performance - Orange Bo ok version
R. Frey and M. Iwasaki

· We want to give Snowmass folks (and ourselves) some idea of p erformance for jet reconstruction

· Full simulations and (esp ecially) the realistic reconstruction of fully-simulated calorimeter events are not ready

· And it will take years for the reconstruction to approach an asymptotic state of happiness. Applied now, this would b e unrealistically p essimistic.

· Fast simulation clearly to o optimistic, but p erhaps would b e near the asymptote (SD p ossibly; L dubious; P no way)

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· Therefore: use energy flow with fast simulation ­ Assume ideal charged-neutral separation. Can include efficiency as fn. of separation later.. . which would b e based on full sim. and recon. · Use single-particle resolutions from tracker (charged) or cal. (neutrals).

· Single-particle resolutions for L confirmed by G. Bower. Need to rep eat for SD (and P?)

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· Key quantities to evaluate jet p erformance: Jet energy resolution and jet-jet mass.

· Explicitly omit ISR and b eamstrah. ­ interested here in the detector contribution to resolution. Radiative effects can b e folded in for the case of interest

· Selections: Neutral clusters: E > 0.1 GeV, | cos | < 0.9 Tracks: | cos | < 0.9 Thrust: | cos | < 0.8 Ї · For jet energy resolution, use e+ e- q q : Demand 2 jets; put b oth in plot · What parameter b est measures cal. resolution: of fit ?
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LDMar01, s = 500 GeV
E_jet (GeV)
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Ej Nent = 1860 Mean = 240.6 RMS = 14.97 Chi2 / ndf = 73.9 / 18 Constant = 150.3 ± 5.754 Mean Sigma = 248.4 ± 0.111 = 3.178 ± 0.08283

LDMar01, s = 100 GeV
E_jet (GeV)
180 160 140 120 100 80 60 40 20 0 10 15 20 25 30 35 40 45 50 55 60
Ej Nent = 1196 Mean = 47.4 RMS = 4.679 Chi2 / ndf = 94.54 / 15 Constant = 144.3 ± 7.313 Mean = 49.19 ± 0.05005 Sigma = 1.266 ± 0.04893

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LDMar01, Jet Energy resolution

Ej /Ej 0.18/ Ej

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· For jet-jet mass resolution, use e+ e- ZZ hadrons: Demand 4 jets Plot all 2-jet mass combinations, or Plot 2-jet masses within hemisphere defined by thrust, or Tag one 2-jet comb. MZ ; plot the other mass pair

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LDMar01, s = 350 GeV, thrust metho d
JJ Mass (GeV)
JJM Nent = 1002 Mean = 78.22 RMS = 17.96 Chi2 / ndf = 63.94 / 46 p0 = 88.47 ± 5.439 p1 = 87.62 ± 0.3097 p2 = 4.932 ± 0.296 p3 = 15.45 ± 1.281 p4 = 65.54 ± 1.67 p5 = 20.32 ± 1.101

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LDMar01, s = 350 GeV, Mass-tag metho d
JJ Mass (GeV)
JJMt Nent = 861 Mean = 91.3 RMS = 33.13 Chi2 / ndf = 84.03 / 46 p0 = 66.5 ± 6.194 p1 = 88.21 ± 0.367 p2 = 3.844 ± 0.4193 p3 = 14 ± 1.991 p4 = 75.86 ± 1.388 p5 = 16.95 ± 1.321

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LDMar01, s = 200 GeV, Mass-tag metho d
JJ Mass (GeV)
JJMt Nent = 1117 Mean = 74.19 RMS = 21.75 Chi2 / ndf = 58.44 / 41 p0 = 68.83 ± 4.28 p1 = 87.16 ± 0.401 p2 = 6.552 ± 0.4193 p3 = 14.57 ± 1.011 p4 = 56.27 ± 3.251 p5 = 31.64 ± 2.828

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LDMar01, s = 650 GeV, thrust metho d
JJ Mass (GeV)

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JJM Nent = 696 Mean = 85.23 RMS = 9.46 Chi2 / ndf = 54.94 / 29 p0 = 90.23 ± 7.344 p1 = 88.69 ± 0.3333 p2 = 3.226 ± 0.3402 p3 = 19.57 ± 3.796 p4 = 81.84 ± 1.048 p5 = 11.3 ± 1.01

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LDMar01 Jet-Jet Mass resolution vs s/2 Ejj

Mjj /Mjj 1.03/ Ejj - 0.03

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LDMar01, s = 500 GeV
JJ Mass (GeV)

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JJM Nent = 930 Mean = 83.27 RMS = 11.74 Chi2 / ndf = 82.56 / 37 p0 = 109.1 ± 8.796 p1 = 89.49 ± 0.3035 p2 = 2.68 ± 0.2579 p3 = 40.57 ± 4.634 p4 = 81.27 ± 0.6849 p5 = 9.459 ± 0.5595

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LDMar01, s = 500 GeV, with ISR and Beamstrah.
JJ Mass
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JJM Nent = 420 Mean = 79.76 RMS = 15.62 Chi2 / ndf = 28.22 / 18 p0 = 85.45 ± 7.172 p1 = 86.28 ± 0.4398 p2 = 4.733 ± 0.3458 p3 = 13 ± 2.047 p4 = 68.52 ± 2.402 p5 = 16.53 ± 1.591

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