1. 1 Plans for the Muon Trigger CSC Note

2. 2 Muon Trigger CSC Studies General performance studies and trigger rate evalution for the full slice Evaluation of fake dimuon triggers studies of the overlaps in the MuCTPi fake dimuon rate evaluation Muon from in flight K/  decay rejection Studies of performance against the pileup + cavern background Evaluation of Trigger Efficiency from data (Z   ) Studies of the muon trigger on the Z and high mass resonances selection (Z'/Graviton). CSC notes have to be finalized by the next Trigger& Physics week (March)

3. 3 Muon Trigger community requires large scale samples of single  to evaluate in great detail the performance of muon L1 and HLT trigger  need of dedicated CSC productions ~15M of events produced in Napoli Tier2 (rel 11.0.42) Production validated against the central ATLAS production Nocal digitization (high statistic does not permit an easy storage of full digitization event) nevertheless some pt-points have been produced with CALO ON in order to study the calorimter muon trigger (isolation, low pt identification) problems in rel 11.0.42 LVL1 threshold names changed recently  not possible to read the LVL2 result from file with recent releases (12) nevertheless it is possible to have the right results by re-running the LVL1 simulation at "reconstruction " level TriggerFlags.doLVL1=True TriggerFlags.readLVL1Muon = False bug in the RPC digit time (fixed in 12) Single  production

4. 4 11.0.42 Production Dataset available on the GRID Muon trigger studies shown in the present T&P week mostly done with these data

5. 5 New Requests of Single Muons 12.0.3 (misalligned geometry) ~16M of events Statistics at low pt evaluated in order to have errors <10% if the efficiency is enough to significatively contribute to the muon rates 4M of events @ pt=6,20GeV required for the LVL2 LUTs determination

6. 6 Pileup + Muon Cavern Background For CSC, cavern background simulation hit files, produced with 11.0.42, are ready and available on grid. Also available on /castor/cern.ch/user/m/muonprod/CSC/cavernbg/sfXX where XX stands for the available safety factors (XX=01, 02, 05, 10). In the mixing procedure the access to the cavern background hits produced with 11.0.4 is slow  simulation with 12.0.3 needed on going Validation of the cavern background simulation when the files will be available

7. 7 Fake di-  Trigger Studies Studies to be done with single muon samples There are geometrical overlap in several regions in muon trigger system to avoid inefficiency due to chamber gaps. Barrel-Barrel Barrel-Endcap Endcap–Endcap They cause a fake LVL1 di-muon trigger from single muons, that would give a rate at LVL1 greater then the expected ~150 Hz rate of real LVL1 di-muons (@10 33 cm 2 s -1 luminosity) Can be solved by MuCTPI or each system. Study to determine the fake di-muon trigger rate caused by single muons and develop the algorithms that can be used to resolve them.

8. 8 Muons from K/  MOORE offline G3 samples, Athena release 10.0.1 MOORE offline: K ,  (|  |<1.2, 0°<  <180°) Similar analysis to be redone with the full muon slice on G4 samples Most of the total trigger rate is due to  from in-flight decay of K/ , expecially for what concerns the low Pt threshold. Dedicated studies have to be performed in order to evaluate the reduction of such contribution from the final rates

9. 9 Muons from K/  (2) 10 5 -10 6 muons from in flight-decay are needed to measure the efficiencies with good precision K/  simulation strategy under study New G4 tools have been released in order to have a meson decay above a given threshold within a given geometrical region (before calorimeters). Can be used within two different approaches with minimum bias events K/  spectra, extracted from (pt-eta) distribution of minimum bias + QCD events, generated as single particles will allow the simulation of more statistics Similar studies in the Bphysics note " Muons from K/pi in B- events" (editor A. Di Mattia), samples and tools can be shared

10. 10 Trigger Studies with physics events Determination of muon trigger efficiencies from data (Z   Zmumu samples background from BBmumu, Wmunu, Ztautau(->mumu) plus the effect of cavern background and pileup Evaluation of the effects of the muon trigger Z  mumu and high mass resonances (Z'). trigger efficiency for Z and Z' (and Z+jets) estimation of the rates at each level effects of the pileup/cavern background on th trigger efficiency/rates

11. 11 Conclusions CSC note is a good opportunity to study in details the full muon trigger slice and optimize the performance detailed LVL1 efficiencies, also at low-pt, with several thresholds full slice, both muon barrel/endcaps, combined reconstruction, several HLT algorithms detailed trigger efficiencies and rates evaluation Most of the work will be done with single muons, large production is necessary Many studies on background rejection (fake dimuons, meson decays and cavern background) Muon trigger efficiency also studied with physics channels