χc production in proton-proton collisions at 7 TeV with CMS experiment

This article presents the cross-section ratio σ(χc2)/σ(χc1) for prompt χc production as a function of J/ψpT in pp collisions at 7 TeV, using 2011 data collected by CMS experiment. The total integrated luminosity corresponds to 4.62fb−1. The measurement is performed by reconstructing the χc radiative decays to J/ψ+γ, where J/ψ decays into two muons. The photons are reconstructed through their conversions into electron-positron pairs in the tracker. The results are compared with two theory predictions, NLO NRQCD and kT factorization models.