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Status of J/ Trigger Simulations for

d+Au Running

Trigger Board MeetingJan 23, 2003

MC & TU

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L0 Topology trigger

Use not only high tower information but also topology information. Azimuth is divided into 6 trigger patches.

L0 performance for Tower > 1 GeV: background rejection factor: 40.6 Trigger efficiency: 50-60%

High tower here

Look here

Or here

Or here

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L2 Energy Resolution with 3-tower cluster

Cluster 3 highest towers in a 3x3 patch

2 tower vs. 3 tower cluster: L2 Mass RMS changes from 668 to 311 MeV

<Ee - Ecl> = 40 MeVRMS = 248 MeV

Resolution ~ 17%/E

Conclusion: need clustering algorithm for L2optimum: 3 tower cluster

3 towercluster

no clustering single tower

3 tower cluster

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Isolation Cuts: subtracting Tower or 3-Tower Cluster

3x3 patches,

what happens if we increase the patch size?

All BG towersPhotonsPionsKaonsKaonsProtons

i high towertowers

itowers

E E

E

electrons background

i clustertowers

itowers

E E

E

Most of the energy is in the cluster.

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Isolation Cuts: 3x3, 5x5, 7x7…

Cut Eff. Electron clusters Rej. Background clusters

3x3 5x5 7x7 3x3 5x5 7x7

0.02 75% 60% 52% 41% 55% 62%

0.04 90% 77% 68% 24% 39% 46%

0.06 97% 86% 76% 15% 29% 36%

0.08 99% 89% 80% 10% 22% 29%

0.1 100% 92% 84% 6% 17% 24%

Integral3x3