engleski

Rapidity and transverse momentum dependence of inclusive J/ψ production in pp collisions at sqrt(s) = 7 TeV

The ALICE experiment at the LHC has studied inclusive J/ψ production at central and forward rapidities in pp collisions at √s = 7 TeV. In this Letter, we report on the first results obtained detecting the J/ψ through the dilepton decay into e+e− and μ+μ− pairs in the rapidity ranges |y| < 0.9 and 2.5 < y < 4, respectively, and with acceptance down to zero pT. In the dielectron channel the analysis was carried out on a data sample corresponding to an integrated luminosity Lint = 5.6 nb−1 and the number of signal events is NJ/ψ = 352 ± 32 (stat.) ± 28 (syst.) ; the corresponding figures in the dimuon channel are Lint = 15.6 nb−1 and NJ/ψ = 1924 ± 77 (stat.) ± 144 (syst.). The measured production cross sections are σJ/ψ (|y| < 0.9) = 10.7 ± 1.0 (stat.) ± 1.6 (syst.) +1.6 −2.3 (syst.pol.) μb and σJ/ψ (2.5 < y < 4) = 6.31 ± 0.25 (stat.)±0.76 (syst.) +0.95 −1.96 (syst.pol.) μb. The differential cross sections, in transverse momentum and rapidity, of the J/ψ were also measured.

ALICE; LHC; J/Psi; 7 TeV; p+p

ALICE Collaboration