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Muon subgroup simulation report. Status report on Torino studies to validate the magnet setup for muon measurement in DY processes. MC data samples. in real life m/p = 10 -6 layout studies for dimuon with ABDYG (1.5 MEv) background studies with PYTHIA (640 KEv)
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Muon subgroup simulation report • Status report on Torino studies • to validate the magnet setup • for muon measurement in DY processes Maria Pia Bussa, ITEP 18/4/2008
MC data samples • in real life m/p = 10-6 • layout studies for dimuon with ABDYG (1.5 MEv) • background studies with PYTHIA (640 KEv) • all interactions switched on Maria Pia Bussa, ITEP 18/4/2008
ABianconi Drell - Yan Generator Benchmark channel: DY @ 15 GeV/c Focus on one single Mμμ range 1.5 < M μμ< 2.5 GeV 1 nb cross section Maria Pia Bussa, ITEP 18/4/2008
New design with more filtering after the endcap Maria Pia Bussa, ITEP 18/4/2008
Barrel design for the simulation • Detector simulated by 3 cm ArCO2 • Muon filter: iron plates 3/6 cm thickness • 9 iron plates 3 cm, inner and outer plates 6 cm, 12 detector layers • Fe equivalent 39 cm Maria Pia Bussa, ITEP 18/4/2008
Endcap design for the simulation • Detector simulated by 2 cm ArCO2 • Muon filter: iron plates 4/6 cm thickness • 6 iron plates with 7 detector layers • Fe equivalent 34 cm • Additional iron: 10 cm thick, followed by virtual detector plane Maria Pia Bussa, ITEP 18/4/2008
additional iron after the endcap additional iron endcap Primary pions, no mm mass cut Maria Pia Bussa, ITEP 18/4/2008
Background and signal kinematics @ vertex bkg dipions barrel endcap DY dimuons Maria Pia Bussa, ITEP 18/4/2008
Bkg and signal kinematics @ B/E entrance (1.5 < Mμμ < 2.5 GeV/c2) bkg pions endcap barrel DY muons Maria Pia Bussa, ITEP 18/4/2008
ABDYG signal distribution exit Barrel = 40 cm Fe eq. exit Endcap = 64 cm Fe eq. 10% DY signal with one m in FS at the exit Maria Pia Bussa, ITEP 18/4/2008
Dipion background distribution normalized to the total number of events • 96% dipion cut by material budget before entrance • at exit E : E+FS : FS = 1 : 2 : 2 Maria Pia Bussa, ITEP 18/4/2008
Primary dipion background rejection in Fe Weak effect with Fe depth in Endcap, better in Barrel Maria Pia Bussa, ITEP 18/4/2008
dimuon/primary dipion ratio 30 cm additional Fe factor 3 Additional cuts from Range System & kinematics e.g. cut on PT factor > 10 expected March 3, 2008 Marco Maggiora - Muon @ GSI 03/2008 13 Maria Pia Bussa, ITEP 18/4/2008
background from secondaries m&p distribution Exit 40 cm Fe equiv in Barrel, 64 cm in Endcap Background survives in Endcap Weak effect of additional Fe Maria Pia Bussa, ITEP 18/4/2008
Hadronic secondary background Fe rejections Hadronic primary background Maria Pia Bussa, ITEP 18/4/2008
CONCLUSIONS • Barrel rejection factor per track: 5 103 • Endcap rejection factor per track: 102 (5 102 after 94 cm) • Barrel rejection factor considering couples: > 106 (40cm Fe) • Endcap rejection factor considering couples: 1.5 105 (after 64cm of Fe; 30cm more lead to 5 105 only) • These rejection factors include primary pions and secondary muons from pions.. • One order of magnitude is missing; extrensive simulations needed on PANDAGRID to design topological and kinematic cuts! • Porting on PANDROOT well on his way Maria Pia Bussa, ITEP 18/4/2008
next steps • Barrel: the desired bkg suppression seems achievable with segmented yoke • Endcap: muon filtering improved with the suggested additional iron after the endcap • Simulation needed for muons from pion decay and to optimize the number of detector layers • Simulations are also needed for other muonic channels • Is the result depending on bkg generator? A cross check with DPM asap Maria Pia Bussa, ITEP 18/4/2008