Update on H  studies Catalin and Tony FTK meeting, July 13, 2006

H  with FTK Step1: look at LVL1 side Step2: look at LVL2 side Similar to Kohei’s study –But the gain comes from modifying the LVL1 side rather than LVL2 LVL1 (+new trigger) LVL2 (+FTK) 40 kHz 200 Hz

Trigger Study – May LOW-LUMHIGH-LUM MU20(20) 2MU6 EM25I(30) 2EM15I(20) J200(290) 3J90(130) 4J65(90) J60+xE60( ) TAU25+xE30(60+60) MU10+EM15I Lepton E T Tau E T Missing E T 15,20,25,30 10,15,20,25 10,15,20

Low Luminosity Regime Signal: 130 GeV H  E T (  ) threshold E T (lep) > 10 GeV E T (  ) threshold E T (lep) > 15 GeV E T (  ) threshold E T (lep) > 20 GeV met>15 met>30 Reminder: - only lepton, tau, and met thresholds are varied - rest of the trigger table stays the same Biggest effect: lowering the lepton E T threshold (up to 15% gain) Trigger efficiency

LVL1 trigger table

LVL1 Triggers LVL1 output rate dominated by the EM and tau+miss.Et triggers. We tuned the fake probability to reproduce the values in the previous table. LVL1 output rates are comparable now: –EM: 12.5 kHz (vs 12 kHz fom Slide5) –Muon: 0.7 kHz (vs 0.80 kHz from Slide5) –Tau+missEt: 1 kHz (vs 2 kHz from Slide5) –Single jet: 0.23 kHz (vs 0.2 kHz from Slide5) –The new trigger would add to the bandwidth 15Hz assumed both Et threshold (lep, tau) are set at 15 GeV a problem for LVL2 where the max output rate is 200Hz.

Step2 – LVL2 rejection Thanks to Paola for pointing us to the CMS algorithm RORO RIRI RSRS leading P T track Recipe: - find leading P T track in a R I =0.1 cone around the jet - require P T (lead. track) > 3 GeV - find tracks within an R S =0.07 cone around lead. Track - count, as before, tracks in the isolation reg: R I <R<R O Jet axis

Requiring N t  1 within  R=0.1 of the  jet 130 GeV Higgs signal

Requiring N t  1 within  R=0.1 of the  jet Sherpa dijet

3,1 2,2 2,1 4,0 3,0 1,2 1,1 2,0 1,0 Max tracks in,out “in” tracks are here w/ P t >1.0 “out” tracks are here w/ P t >0.5 factor of ~1.4 optimum R O =0.3, P T Sig >3.0 GeV/c R O =0.5, P T Sig >10.0 GeV/c Curves correspond to different R O & min leading P T. R S =0.07, R I =0.1 for all. Higgs 130 GeV

3,1 2,2 2,1 4,0 3,0 1,2 1,1 2,0 1,0 Max tracks in,out factor of ~10 R O =0.3, P T Sig >3.0 GeV/c R O =0.5, P T Sig >10.0 GeV/c Curves correspond to different R O & min leading P T. R S =0.07, R I =0.1 for all. “in” tracks are here w/ P t >1.0 “out” tracks are here w/ P t >0.5 Sherpa Dijet

Step1+Step2 From adding the lepton+tau trigger we gain about 15% signal, and add  O(10)Hz into LVL2 For the point shown, we reduce LVL2 contribution to 1-2 Hz, while keeping 65% of signal. Net gain 9-10% signal Curves correspond to different R O & min leading P T. R S =0.07, R I =0.1 for all. 3,1 2,2 2,1 4,0 3,0 1,2 1,1 2,0 1,0

Conclusions Studied efficiency/rejection optimization using the CMS algorithm: –Dijet rejection: 1/2 – 1/100 –Signal efficiency: 40%-70% Tuned lepton fake rates to match the default LVL1 output rates Using a lepton+tau trigger with 15 GeV Et thresholds, we find a 5-10% signal gain Need to run over a larger dijet sample