OS dimuon invariant mass distribution fit in the J/psi and Psi(2S) region, at forward rapidity, in PbPb collisions at 5.02 TeV, in the centrality range 70-90% and for pT < 0.3 GeV/c. The J/psi and Psi(2S) signals are fitted with a Crystal Ball extended function and the background with a quadratic Variable Width Gaussian.
137 runs QA selected of the AOD175 set from the 2015 Run-2 Pb–Pb data taking at 5.02 TeV
LHC15o period and muon calo pass 1 reconstruction
Physics Selection applied
Trigger selection : CMUL7-B-NOPF-MUFAST
Standard cuts are applied on the muon track selections:
- 4 < eta < -2.5 on both muons belonging to the dimuon
- 170 < theta_abs < 178 degree on both muons, where theta_abs is the polar angle of the muon track at the end of the absorber
- Both muon tracks reconstructed in the tracking chambers should match a trigger track reconstructed in the trigger system, above the low pT trigger threshold
- Both muon tracks must pass the pxDCA cut set at 6 sigma
Rapidity selection is applied on the dimuon candidates : 2.5 < y < 4.