1. Ernesto Migliore MCWS Frascati 28 Feb 06 PRETTY GOOD SIMULATION ERNESTO MIGLIORE* Università di Torino/INFN *Disclaimer: not a PGS expert

2. Ernesto Migliore MCWS Frascati 28 Feb 06 c |----> pgs_next_event... c | c |----> tauola_scan... c | c |----> pgs_trigger... c | c |----> pgs_recon... c | c |----> pgs_user_analysis c |---> pgs_write_event Fortran library (former SHW ) by John Conway Higgs/SUSY Tevatron RUN II http://www.physics.ucdavis.edu/~conway/research/software/pgs/pgs.html “native” interafce to PYTHIA and ISAJET interface to user events through STDHEP Note: hadrons to be supplied by the user  decays + polarization Output of selected events through STDHEP + interfaces to HBOOK routines Detector Simulation Event loop

3. Ernesto Migliore MCWS Frascati 28 Feb 06 PROCESSING OF EVENTS pgs_trigger | |---> pgs_find_tracks make track list |---> pgs_fill_cal calorimeter energy array |---> pgs_find_clusters calorimeter energy clusters |---> pgs_find_TTT_trig pgs_recon |---> pgs_find_RRR From ISTHEP and PHEP Smearing of pT, E EM and E HAD Fixed size cone  R TTT =  /e, , , jet, MET RRR =  /e, , , jet, b, c Analysis of reconstructed objects on events selected on the basis of trigger objects

4. Ernesto Migliore MCWS Frascati 28 Feb 06 SIMULATION OF THE DETECTOR main detector effects: –pT smearing –E EM, E HAD smearing –Energy deposited in towers (granularity of HCAL) –Tag efficiency (  -ID,  -tagging, b/c-tagging) Detector parameters partly from cards partly hard-coded

5. Ernesto Migliore MCWS Frascati 28 Feb 06 LHC_DETECTOR_PARAMETERS LHC ! parameter set name 81 ! eta cells in calorimeter 63 ! phi cells in calorimeter 0.1 ! eta width of calorimeter cells 0.099733101 ! phi width of calorimeter cells 0.1 ! electromagnetic calorimeter resolution * sqrt(E) 0.8 ! hadronic calorimeter resolution * sqrt(E) 0.2 ! MET resolution 0.00 ! calorimeter cell edge crack fraction 3.0 ! calorimeter cluster finding seed threshold (GeV) 0.5 ! calorimeter cluster finding shoulder threshold (GeV) 0.70 ! calorimeter cluster finder cone size (delta R) 1.0 ! outer radius of tracker (m) 2.0 ! magnetic field (T) 0.000005 ! sagitta resolution (m) 0.98 ! track finding efficiency 0.30 ! minimum track pt (GeV/c) 2.0 ! tracking eta coverage Calorimeter  HCAL 5  m   pT/pT=4x10 -5 pT (GeV)

6. Ernesto Migliore MCWS Frascati 28 Feb 06 CALORIMETRY (  =0) CDFATLASCMS EM Pb+SciPb+LArPbWO 4 19 X 0 24 X 0 26 X 0 1 I 1.2 I 1.1 I HADFe+Sci Cu+Sci 4.5 I 7.2 I 5 I “Hard-coded” single pion energy –100% HAD 50% times –25% EM + 75% HAD 50% times EM cluster definition: E HAD /E EM <12.5%

7. Ernesto Migliore MCWS Frascati 28 Feb 06 C.Weiser FNAL 18Jan06 CMSPGS “Hard-coded”  =0 eff(b)=50% v3.3 LHCO b-TAGGING uds gluons c Track counting (N=3)  q =# jet q tagged as b /# jets q

8. Ernesto Migliore MCWS Frascati 28 Feb 06 SIMULATION OF THE DETECTOR main detector effects: –pT smearing –E EM, E HAD smearing –Energy deposited in towers (granularity of HCAL) –Tag efficiency (  -ID,  -tagging, b/c-tagging) Detector parameters partly from cards partly hard-coded Not included: –B deflection of charged tracks (effects on the jet broadness) –pile-up (relevant for high luminosity analyses) –underlying event (depending on the MC) –background processes

9. Ernesto Migliore MCWS Frascati 28 Feb 06 OUTLOOK/DISCUSSION PGS validation/tuning –vs. ATLAS and CMS “fast” simulation? –vs. ATLAS and CMS “full” simulation? –atlas.par, cms.par, lhcdet.par? Which observable in which process (which MC)? –m(ℓℓ) in Z (+jets) –MET in W (+jets) or tt –(isolated  ) Size of the cross-section you want to investigate (nb/pb/fb)