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.)-2.3+1.6(syst.pol.)μb and σJ/Ψ(2.5<y<4)=6.31±0.25(stat.)±0.76(syst.)-1.96+0.95(syst.pol.)μb. The differential cross sections, in transverse momentum and rapidity, of the J/Ψ were also measured.
|Number of pages||14|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|State||Published - 1 Jan 2011|
Scopus subject areas
- Nuclear and High Energy Physics