Tracey Berry1 Looking into e &  for high energy e/  Dr Tracey Berry Royal Holloway

Tracey Berry2 Trigger Investigations Using the Gee 500 GeV k/m Pl =0.010 dataset Pythia 5620 Looking at the trigger efficiency. Run over 5000 G  ee M G =500 GeV events

Tracey Berry3 G  ee events: Trigger Final trigger decision for 5000 events L1 Dec, L2Dec, EFDec e25i trigger 4447, 4179, 3868, , , e60 trigger 4974, 4789, 4478, , , e15i trigger 2450, 1841, 1397, 0.49, , g60 trigger 4974, 4872, 4803, , , g20i trigger 2450, 0, 0, 0.49, 0, 0 j160 trigger 4997, 4792, 4620, , , j120 trigger 4952, 4763, 4516, , , j65 trigger 4952, 1891, 1503, , , j50 trigger 4952, 699, 461, , , bjet35 trigger 5000, 4997, 4997, 1, , tau10i trigger 4939, 4606, 4573, , , tau15i trigger 4921, 4596, 4513, , , tau25i trigger 4959, 4663, 4598, , , tau35i trigger 4948, 4641, 4583, , , mu6 trigger 105, 52, 36, 0.021, , mu20i trigger 20, 13, 8, 0.004, , Jet and Tau triggers more efficient for signal than the e60 trigger!! g60 trigger most efficient Investigate what makes e60 trigger inefficient ….! But jet triggers have a large prescale

Tracey Berry4 Aside….. My discoveries (mistakes!!) in rerunning the trigger! Correct Method!

Tracey Berry5 Trigger Steering –You can only tighten the triggers, not loosen them –(even when you re-run the trigger hypo) Can not loosen triggers: because of the way the trigger steering works L1 L2 EF e.g. if in original trigger the event failed the EF cuts after passing L3 – then if you loosen the EF cuts then the object is just not in the record to be counted – so the trigger print out says it passed, but the trigger decision maker final count will not count this event  very odd results! 9 / 10 pass EF trigger print out, but final trigger decision print out gives 8 / 10 etc…. !

Tracey Berry6 Triggers You can only tighten the triggers, not loosen them –(even when you re-run the trigger hypo) So for high Pt analysis want to loosen the e60 triggers To do this have to use e10 trigger (dummy trigger) Which has L1: EM > 7 GeV L2: Pass All L3: Pass All So make the e10 trigger become the e60 trigger by applying the e60 cuts to the e10 trigger – since I can tighten the e10 cuts to the e60 values However, e10 L1 trigger called EM01 and name suppressed since does not begin L1 ! So have used L1_EM5 which requires EM ET>3 GeV!

Tracey Berry7 Mimicking the e60 trigger in mimicking the e60 trigger using the e10 path For 5000 events Events Efficiency Trigger L1 L2EF L1 L2 EF e60 trigger 4974, 4789, 4478, , , “e10” trigger 4998, 4790, 4479, , 0.958, Note L1 different – but can’t change L1 Efficiencies same Now to change/optimise e60 trigger cuts….

Tracey Berry8 L1 Decision Final trigger decision for 5000 events L1 Dec, L2Dec, EFDec e25i trigger 4447, 4179, 3868, , , e60 trigger 4974, 4789, 4478, , , e10 trigger 4998, 4790, 4479, , 0.958, e15i trigger 2450, 1841, 1397, 0.49, , g60 trigger 4974, 4872, 4803, , , g20i trigger 2450, 0, 0, 0.49, 0, 0 j160 trigger 4997, 4792, 4620, , , j120 trigger 4952, 4763, 4516, , , j65 trigger 4952, 1891, 1503, , , j50 trigger 4952, 699, 461, , , bjet35 trigger 5000, 4997, 4997, 1, , tau10i trigger 4939, 4606, 4573, , , tau15i trigger 4921, 4596, 4513, , , tau25i trigger 4959, 4663, 4598, , , tau35i trigger 4948, 4641, 4583, , , mu6 trigge r 105, 52, 36, 0.021, , mu20i trigger 20, 13, 8, 0.004, , Looking at the L1 Decision, Note that the j160 trigger is more efficient than the L1 e60 and g60 L1 e60 and g60 are identical : em Et>50 GeV Can’t change the L1 decisions

Tracey Berry9 L2 Decision Final trigger decision for 5000 events L1 Dec, L2Dec, EFDec e25i trigger 4447, 4179, 3868, , , e60 trigger 4974, 4789, 4478, , , e10 trigger 4998, 4790, 4479, , 0.958, e15i trigger 2450, 1841, 1397, 0.49, , g60 trigger 4974, 4872, 4803, , , g20i trigger 2450, 0, 0, 0.49, 0, 0 j160 trigger 4997, 4792, 4620, , , j120 trigger 4952, 4763, 4516, , , j65 trigger 4952, 1891, 1503, , , j50 trigger 4952, 699, 461, , , bjet35 trigger 5000, 4997, 4997, 1, , tau10i trigger 4939, 4606, 4573, , , tau15i trigger 4921, 4596, 4513, , , tau25i trigger 4959, 4663, 4598, , , tau35i trigger 4948, 4641, 4583, , , mu6 trigge r 105, 52, 36, 0.021, , mu20i trigger 20, 13, 8, 0.004, , Note that the L2 g60 trigger is more efficient than the L2 e60 (83/4974=1.7%) So what’s different in the g60 and e60 L2 trigger cuts? e60 has track- matching which g60 does not have It’s the E/P in the cuts which make it inefficient – since the e have tracks - so shouldn’t be in!

Tracey Berry10 L2 decisions I looked at a few events and found that the E/P cut was causing an inefficiency… e60: L2 CAL cuts are optimised in the following eta bins: |eta| ≤ 0.75, 0.75 < |eta| ≤ 1.5, 1.5 < |eta| ≤ 1.8, 1.8 < |eta| ≤ 2.0, 2.0 < |eta| ≤ 2.5. ET(cluster) threshold = 53 GeV ET of leakage into hadronic calo 90GeV Rcore threshold > [0.93, 0.92, 0.92, 0.93, 0.92] Eratio > [0.85, 0.75, 0.80, 0.85, 0.85] As above except: g60: ET of leakage into hadronic calo 90GeV e60: L2 IDCAL – g60 has no such cuts optimised in 4 eta bins: |eta| ≤ 0.75, 0.75 < |eta| ≤ 1.5, 1.5 < |eta| ≤ 2.0, 2.0 < |eta| ≤ 2.5. As track algorithms IDScan is used. track pT > 5 GeV E/p > [0.0, 0.0, 0.0, 0.0] & E/p < [3.5, 3.5, 4.5, 5.5]  Eta(cluster-track) < [0.015, 0.010, 0.015, 0.02]  Phi(cluster-track) < [0.07, 0.07, 0.07, 0.07] e60 has track-matching which g60 does not have since the e have tracks- so shouldn’t be inefficient! But e60 also has E/P cut

Tracey Berry11 Remove E/P cut at L2 and EF With E/P cut: L1 L2 EF e60 trigger 4974, 4789, 4478, , , e10 trigger 4998, 4790, 4479, , 0.958, g60 trigger 4974, 4872, 4803, , , With E/P cut removed from L2 but not EF e60 trigger 4974, 4789, 4478, , , e10 trigger 4998, 4887, 4522, , , g60 trigger 4974, 4872, 4803, , , With E/P cut removed from L2 and EF e60 trigger 4974, 4789, 4478, , , e10 trigger 4998, 4887, 4727, , , g60 trigger 4974, 4872, 4803, , , Conclusion: The E/P cut at L2 makes the e60 trigger less efficient than the g60 at L2 for G  ee MG=500 GeV Now “e10” trigger is more efficient than the g60 at L2 Removing E/P cut gains 97/4998=1.9%

Tracey Berry12 Remove E/P cut at L2 and EF With E/P cut: L1 L2 EF e60 trigger 4974, 4789, 4478, , , e10 trigger 4998, 4790, 4479, , 0.958, g60 trigger 4974, 4872, 4803, , , With E/P cut removed from L2 but not EF e60 trigger 4974, 4789, 4478, , , e10 trigger 4998, 4887, 4522, , , g60 trigger 4974, 4872, 4803, , , With E/P cut removed from L2 and EF e60 trigger 4974, 4789, 4478, , , e10 trigger 4998, 4887, 4727, , , g60 trigger 4974, 4872, 4803, , , Removing E/P requirement at L2 and EF makes the e60 trigger eff increase from 90 to 95 %

Tracey Berry13 E/P Antonella: This effect on E/p that you see could be due to some worsening of momentum resolution at high energy. (The inner detector momentum resolution is something like 30-40% up at 1 TeV. The electron resolution from the calorimeter is very good at these energies.) Plan to investigate what makes E/p such a bad variable for electrons from gravitons -- is it p or E that messes things up? What happens to sigma(p)/p as the energy increases? Taking misalignments into account, which are unavoidable, especially with early data, things can only go from bad to worse... Plan to compare sigma(p)/p and sigma(E)/E for G->ee and Z->ee (and maybe also single electrons GeV ones should be available) Kevin: Another possibility is that the electron is radiating a photon early on which is in the direction of the electron so contributing to the E but not the track momentum. Though this should happen at the Z as well and probably accounted for in the default cuts. Future Plans….investigate further…

Tracey Berry14 e60 EF cuts e60: L2 Track matching: Delta Eta(cluster-track) < [0.015, 0.010, 0.015, 0.02] Delta Phi(cluster-track) < [0.07, 0.07, 0.07, 0.07] e60: EF cluster ET > 57.5 GeV Delta Eta(cluster-track) < Delta Phi(cluster-track) < fraction of TR hits: disabled At EF level the track matching is tightened:

Tracey Berry15 e60 EF inefficiency investigations With E/P cut removed from L2 and EF L1 L2 EF e60 trigger 4974, 4789, 4478, , , e10 trigger 4998, 4887, 4727, , , g60 trigger 4974, 4872, 4803, , , loosen track matching of EF to L2 values with no E/P cut at L2 and also EF: e60 trigger 4974, 4789, 4478, , , e10 trigger 4998, 4887, 4771, , , g60 trigger 4974, 4872, 4803, , , Still need to investigate what is making EF cuts for e60 less efficient than the EF cut for g60 trigger

Tracey Berry16 Study E/P Investigate what is making EF cuts for e60 less efficient than the EF cut for g60 trigger Look at 1 TeV Zee sample Investigate more into electron identification for high energy electrons Longer term: is 96 % using the g60 trigger efficient enough?! Or decide if we want to propose a e120 trigger? (Look at different mass G samples (if/when available)) Future Plans

Tracey Berry17 BACK UP SLIDES!

Tracey Berry18 EF cuts e60 cluster ET > 57.5 GeV Delta Eta(cluster-track) < Delta Phi(cluster-track) < fraction of TR hits: disabled g60 cuts are optimised in the following eta bins: |eta| ≤ 0.75, 0.75 < |eta| ≤ 1.5, 1.5 < |eta| ≤ 1.8, 1.8 < |eta| ≤ 2.0, 2.0 < |eta| ≤ 2.5. The default cut values are ET (EM) > [55.*GeV, 55.*GeV, 55.*GeV, 55.*GeV, 55.*GeV] f1 > [0.005,0.005,0.005,0.005,0.005] EThad < [ , , , , ] e237/e277 > [ , , , , ] weta2 < [ , , , , ] e233/e277 > [ , , , , ] e2tsts1/emisn1 < [ , , , , ] wtots1 < [ , , , , ] fracs1 < [ , , , 0.4, 0.4] weta1 < [0.8, , 0.8, 0.8, 0.8]

Tracey Berry19 L2 EM Definitions TrigL2PhotonHypo In this hypothesis the selection is based on the ET of the EM cluster and on various shower shape quantities. The transverse energy ET calculated using the energies of all the electromagnetic-calorimeter layers in a Delta Eta x Delta Phi =3 x 7 standard cell area within the LVL1 RoI (standard cells cover an area of Delta Eta x Delta Phi ~ x 0.025). Note, currently the ET is not corrected for leakage outside the cluster.RoI The hadronic transverse energy EThad within Delta Eta x Delta Phi =0.2 x 0.2. The ratio Rcore = E37/E77, of energy contained in a Delta Eta x Delta Phi =3 x 7 window to that in a 7 x 7 window in the second sampling of the EM Calorimeter. The fractional difference in energy between the strip with the maximum energy E1, and the second maximum E2, in the first sampling of the EM Calorimeter. The fraction is calculated as Eratio = (E1 - E2)/(E1 + E2). As there are no strips in the cuts are ot applied if the shower centre is in The above shower shape variables are eta dependent and in the actual selection different cut values are chosen for different eta regions.

Tracey Berry20 EF EM Definitions TrigEFPhotonHypo At the Event Filter the selection is based on cluster quantities. The following selection is applied. The transverse energy ET calculated using the energies of all the electromagnetic-calorimeter layers in a Delta Eta x Delta Phi =3 x 7 fraction of energy found in em Sampling 1: f1 ET leakage into had calo: EtHad?? uncorrected energy in 3x7 cells /3x7 cells in em sampling 2: e237/e277 corrected width in 3x5 cells in the 2nd sampling: weta2 uncorrected energy in 3x3 cells /3x7 cells in em sampling 2: e233/e277 2nd maximum in strips/energy of strip with min between max 1 & 2 : e2tsts1/emisn1 total width in em sampling 1 in 20 strips: wtots1 energy in strips outside core (E(+-7)-E(+-3))/E(+-7): fracs1 corrected width in 3 strips in the 1st sampling: weta1 The above shower shape variables are eta dependent and in the actual selection different cut values are chosen for different eta regions.