90 likes | 220 Views
Muon PRS MC production for the 2004 Data Challenge Silvia Arcelli, Dimitri Bourilkov, Alexei Drozdetski, Stefano Marcellini, Jason Mumford, Andrea Perrotta, Marco Zanetti. Baseline requirements for the definition of the PRS Muon samples to be generated for the DC04:
E N D
Muon PRS MC production for the 2004 Data Challenge Silvia Arcelli, Dimitri Bourilkov, Alexei Drozdetski, Stefano Marcellini, Jason Mumford, Andrea Perrotta, Marco Zanetti • Baseline requirements for the definition of the PRS Muon samples to be generated for the DC04: • Have a “Realistic” representation of our HLT output(Minimum Bias, W’s, Z’s, tt) • Satisfy needs for Alignement studies (Z’s,W’s) • Produce Monte Carlo samples useful for the full analyses in the Physics TDR • PRS meeting, Muon Week, 10 apr 2003
Generation Setup (common to all PRS groups) • PYTHIA 6.2 with CTEQ5L PDF • note: switching from GRV4L to CTEQ5L pdf, cross-sections for some processes • (MB, tt) vary by ~ -30% • Complex Multiple Interaction Model with tune from A.Moraes et al (on ISR, UA5, Tevatron data) for best possible description of the Minimum Bias + • underlying event: • The underlying event model • affects significantly the event • particle multiplicity and variables • used in the analysis (isolation, • energy flows...)
Candidates for PRS/m “full-Analyses” in the P-TDR: 4-muon Topology 2-muon Topology H ZZ* 4mH WW 2m2n (sel) =O(1) fb (sel) =O(10) fb Z’ 2m (sel) =O(1-100) fb Channels relevant already after 10 fb-1 collected luminosity in the first year of data taking. Z’ analysis is also a very good benchmark under the point of view of the calibration of the muon system. Generation dominated by background samples: generated statistics range from 10-100 fb-1, always enough to have an uncertainty of the background less than 10% of the accepted signal at the final selection step.
BG for H WW 2m2n Events to be passed to full simulation/reconstruction: • Minimum bias includes only bb events (Parton Fusion, about 1/3 of the total bb cross-section). Will be re-normalized accordingly and cross-checked using QCD di-jets generation foreseen for the b/tau, e/gamma PRS. • Z/g * forced to muons and taus, fraction of events from other decays in the relevant kinematic acceptance is less than 1.5%. This sample will also be useful for alignement studies.
BG for H ZZ* 4m • Cut on muon Pts lowered wrt preliminary requests at the last CMS week for consistency with the Higgs PRS group requests • 4 muon tt background now generated by Higgs PRS group with both W’s forced to l, as the equivalents for H 4e, 2e2 channels. To estimate residual fraction of non-prompt muons after isolation + selection criteria can use the di-muon tt sample, O(5k) 4 events expected. • Common COMPHEP Zbb generation, we need to interface it to Pythia selecting the Z , b +X decays
BG for Z’2m • Di-boson and tt backgrounds are lower priority requests, they • represent ~ 5% of the principal background from Drell-Yan • Other backgrounds from bb, cc have still to be investigated, but expected • to give even smaller contributions
Other samples: • Filter a single and di-muon samples out of the 100 M QCD di-jets events • production requested by the b/tau and e/gamma groups: • Useful for comparison with our MB dedicated bb production and to estimate • residual component from cc, light flavours • Dedicated code given to Veikko to be released in cmkin03 • (/afs/cern.ch/cms/Physics/muon/CMSIM/cmsim130/mufilter/kis_mufilter.F)
We will filter single and di-muon events with these thresholds: • 1 : Pt > 14 GeV • 2 : Pt1 > 7 GeV, Pt2 > 7 GeV • Estimated # of filtered events on 100 M QCD di-jets with pt(hat)[50-80]: • (all) = 0.021 mb • (1+X, Pt> 14 GeV) = 80 nb 400 k events • (2+X, Pt1,Pt2> 7 GeV) = 5 nb 20 k events • (2+X, Pt1>20 Pt2> 10 GeV) = 0.3 nb 1 k events • Note: pt(hat) cutoffs select a portion of the muon cross-section, preferentially with • high Pt muons • Lower priority: dedicated samples of low pt muons to simulate background due to superimposed muons from different events in the same BX: • ~ 10 k 1-muon Pt>10 GeV sample (W+MB single-muon event) • ~ 1 k 2-muon Pt1, Pt2 > 5 GeV sample (Z+MB di-muon event) • Would need extra code (same as last year), we need to think about this.
Muon PRS Request for MC Production, summary Total is ~7 M. Code ready and given to Veikko, requests will be submitted as soon as cmk003 is released ( expected within this week)