Prompt and non-prompt J/ψ production in pp collisions at $\sqrt{s} = 7$ TeV

Abstract

The production of J/ mesons is studied in pp collisions at s = 7 TeV with the CMS experiment at the LHC. The measurement is based on a dimuon sample corresponding to an integrated luminosity of 314 nb -1 . The J/ differential cross section is determined, as a function of the J/ transverse momentum, in three rapidity ranges. A fit to the decay length distribution is used to separate the prompt from the non-prompt (b hadron to J/) component. Integrated over J/ transverse momentum from 6.5 to 30 GeV/c and over rapidity in the range |y| < 2.4, the measured cross sections, times the dimuon decay branching fraction, are 70.9 2.1(stat.) 3.0(syst.) 7.8(luminosity) nb for prompt J/ mesons assuming unpolarized production and 26.0 1.4(stat.) 1.6(syst.) 2.9(luminosity) nb for J/ mesons from b-hadron decays.