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This study aims to investigate the possibility of low pT recovery using the MB1 alone for J/psi reconstruction in an inclusive pp sample, specifically focusing on the early LHC days for calibration signals. Samples from the CMS production, including J/psi, Z, and inclusive muon and di-muon samples, have been copied onto the Padua cluster. These samples can be read with CMSSW_1_2_0 version installed on the cluster, and an analyzer example is provided in the CMSSW branch. The study includes normalization of the samples and reconstruction of J/psi and Z mass resonances.
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First look to inclusive pp-> N*mu+X samples • using CMSSW_1_2_0 • J/psi & Z mass resonances • (aiming for calibration signals in early LHC days…) • Possibility of “low pT recovery” using MB1 alone
J/psi reconstruction in inclusive pp sample A sub-sample of the (huge) official CMS production for first physics & HLT tests with CMSSW code (1_2_x) has been copied on the Padua cluster:
J/psi reconstruction in inclusive pp sample Specifically, on : /cms6/data/MCdata/1_2_0 of lxcmssrvN nodes (N=1,2,3), you will find: W_munu_00x.root (~10 Kev) Z_mumu_00x.root (~5 Kev) pp_Jpsi_mumu_00x.root (~10 kev) pp_muX_00x.root (~60 keV, inclusive muon from QCD sample) enreached”) pp_mumuX_00x.root (~20 keV, inclusive di-muons from QCD sample) Readable with CMSSW_1_2_0 version installed on the cluster; analyzer example in the CMSSW branch: .../src/ RecoMuon/GlobalMuonProducer/test : (see: http: //cms.pd.infn.it/software/MCana/MCana_Pd_page.html )
Samples normalization [ 6 h of DAQ @ L=1029cm-2s-1 ] The pp_1muX sample is equivalent to Lint 2 nb-1 integral event rate pp m X sample generator cut DAQ TDR, p. 308 Lint= 2 nb-1
Samples normalization W munu sample Lint=2 nb-1 s(pp W mn) 18 nb N= 10 kev Lint~ 550 nb-1 ppmX (no muon isolation required!) W mn
Samples normalization (III) The pp_2muX sample is equivalent to Lint 50 nb-1 Lint=50 nb-1 (1 week DAQ @ 1029) pp 2m X sample pT(m1), pT(m2) > 3 GeV/c2 pp Z 2m sample pp 2m X sample Lint=2 nb-1 (no muon isolation required!) pp m X sample [ The Z_2muX sample (5 Kev) is equivalent to Lint 2500 nb-1 ] ( s (ppZ2m ) 2 nb ) (normalization factor: pp_2mu/ pp_1mu= 25.8 )
Reconstruction: Z 2mu sample StandAlone cut (h,f) matching efficiency resolution Global
Reconstruction:pp 1mu X sample StandAlone (h,f) matching efficiency resolution (Dh2+Df2)1/2 dpT/pT pT Global cut
Mass reconstruction Muon Global reconstruction (Muon det+Tracker): Lint=50 nb-1 generated (no muon isolation required) reconstructed 200 J/psi
Mass reconstruction StandAlone Muon reconstruction (Muon det.only): Lint=50 nb-1 (no muon isolation required) Caveat: in 1_2_0 vertex constraint not yet implemented; significant improvement expected in 1_3_0 (R.Bellan)
“MB1 reconstruction”in pp_1muX sample When no STA muon reconstructed: look for MB1 segment and assume muon from prim.vertex coil (Normalized to TOTAL nr. of muons)