Updated measurements of exclusive J/ψ and ψ(2S) production cross-sections in pp collisions at √s=7 TeV

CERN-LHC. The differential cross-section as a function of rapidity has been measured for the exclusive production of J/ψ and ψ(2S) mesons in proton-proton collisions at √s=7 TeV, using data collected by the LHCb experiment, corresponding to an integrated luminosity of 930 pb−1. The cross-sections times branching fractions to two muons having pseudorapidities between 2.0 and 4.5 are measured to be

σpp→Jψ→μ+μ−(2.0<ημ±<4.5)=291±7±19 pb,

σpp→ψ(2S)→μ+μ−(2.0<ημ±<4.5)=6.5±0.9±0.4 pb,

where the first uncertainty is statistical and the second is systematic. The measurements agree with next-to-leading order QCD predictions as well as with models that include saturation effects.