High energy photon pairs from RS-1 Gravitons: L1/HLT Studies

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High energy photon pairs from RS-1 Gravitons:

L1/HLT Studies

Vladimir Litvin, Toyoko OrimotoCaltech, CMS

WG4 Group Meeting01 June 2007

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Introduction

• Study to investigate L1 and HLT (in)efficiencies and optimize selection for an express stream for very high energy diphoton events

• MC Samples: • Produced at Caltech & Fermilab • CMSSW_1_3_1_hlt2 with additional CVS tags:

• V00-00-53 HLTrigger/btau• V00-00-26 HLTrigger/xchannel• V01-06-06 RecoLocalTracker/SiPixelClusterizer• V01-00-06 L1Trigger/L1ExtraFromDigis• V02-00-06 L1Trigger/L1ExtraFromMCTruthProd• V00-00-67 HLTrigger/Configuration

• CMSSW_1_3_1_hlt3• No Pileup

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MC Samples

• Signal RS-1 G: • ~90k events (131_hlt2) and ~80k (131_hlt3) each for 750,

1250, 1000, & 1500 GeV mass samples (with c = 0.1)• Background:

• Born: ~100k (131_hlt2) and ~100k (131_hlt3) events• Box: ~300k (131_hlt2) and ~100k (131_hlt3) events• CKIN(1) = 200 GeV

• low limit of the invariant mass of the two outgoing photons, with high end is set to infinity

• Done intentionally to reduce the number of events to produced while keeping the most useful part of the backgrounds for our studies.

born box

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Invariant Masses

1443.0 ± 0.326.6 ± 0.3

720.5 ± 0.115.0 ± 0.2

960.5 ± 0.219.9 ± 0.2

Still need energy correction

Candidates reconstructed from two Island Basic Clusters from ECAL Barrel/Endcap with pt>(30) 100 GeV

born box

750 1000 1500

Pt_photons > 30Pt_photons > 100

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L1 Trigger Efficiencies (131_hlt2)# non-zero L1 bits

per event L1 bits set to 1

750 GeV

born

box

1000 GeV

1500 GeV

# non-zero L1 bits per event L1 bits set to 1

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L1 Trigger Efficiencies (131_hlt3)# non-zero L1 bits

per event L1 bits set to 1

750 GeV

born

box

1000 GeV

1500 GeV

# non-zero L1 bits per event L1 bits set to 1

1250 GeV

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L1 Egamma Efficiencies (131_hlt2)

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HLT Efficiencies (131_hlt2)# non-zero HLT bits

per event HLT bits set to 1

750 GeV

born

box

1000 GeV

1500 GeV

# non-zero HLT bits per event HLT bits set to 1

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HLT Efficiencies (131_hlt3)# non-zero HLT bits

per event HLT bits set to 1

750 GeV

born

box

1000 GeV

1500 GeV

# non-zero HLT bits per event HLT bits set to 1

1250GeV

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HLT Egamma Efficiencies

• 131_hlt2:

• 131_hlt3:

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HLT Egamma Efficiencies

• Decrease in EG HLT efficiencies with increasing mass resonance is due to tight cut on energy deposition in HCAL for EG objects…

• If E > 6 GeV in HCAL for cluster from ECAL Barrel (8 GeV for ECAL Endcap), then the HLT object is considered *not* an EG object..

• Currently this cut is too tight for our very high energy diphotons

• Use HoE cut instead…Will be implemented shortly in CMSSW_1_3_1_hlt4

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Selection

• Invariant mass, pt cuts• Shape (S1/S9, S9/S25)• ECAL Isolation• HCAL energy deposition• Track Isolation• Jets

• Plots will be shown for only 750 GeV sample & born and box backgrounds

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ECAL S1/S9 (131_hlt2)

Note: this is only for Barrel

Higher energy photon Lower energy photon


750 GeV

born

box

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750 GeV

born

box

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Pt_photons > 30Pt_photons > 100 750

GeV

born

box

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GeV

born

box

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ECAL Isolation (131_hlt2)


Energy from basic clusters summed within R cone of 0.3 around basic cluster of photon candidates


GeV

born

box

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ECAL Isolation (131_hlt3)


Energy from basic clusters summed within R cone of 0.3 around basic cluster of photon candidates


GeV

born

box

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HCAL Energy Deposit: HBHE (131_hlt2)

Energy from HCAL Rechits summed within R cone of 0.3 around basic cluster of photon candidate



750 GeV

born

box

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HCAL Energy Deposit: HBHE (131_hlt3)




750 GeV

born

box

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HCAL Energy Deposit: HO (131_hlt2)




750 GeV

born

box

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HCAL Energy Deposit: HO (131_hlt3)




750 GeV

born

box

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Tracker Isolation (131_hlt2)



750 GeV

born

box

Number of tracks (with pt >10) within R cone = 0.3 around basic cluster of photon candidate Check also pt=[3,5] and R=[0.4,0.5]

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Tracker Isolation (131_hlt3)



750 GeV

born

box

Number of tracks (with pt >10) within R cone = 0.3 around basic cluster of photon candidate Check also pt=[3,5] and R=[0.4,0.5]

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Jets (131_hlt2 + pt>30 GeV)

PtnJets eta phi

750 GeV

born

box

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PtnJets eta phi

750 GeV

born

box

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Next Steps

• Production:• CMSSW_1_3_1_hlt4• Produce gamma+jet and QCD backgrounds with

generator preselection (working on filter now)• CompHep events for 2gamma+2jets and

gamma+3jets (not the top priority now) • Analysis:

• HoE selection• Energy correction

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Backup Slides

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All L1 Efficiencies (131_hlt2)

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All HLT Efficiencies (131_hlt2)

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PtnJets eta phi

750 GeV

born

box

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PtnJets eta phi

750 GeV

born

box

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PtnJets eta phi

750 GeV

born

box

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PtnJets eta phi

750 GeV

born

box

High energy photon pairs from RS-1 Gravitons: L1/HLT Studies

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