Measurement of the relative prompt production rate of χc2 and χc1 in pp collisions at [Formula: see text]

Eur Phys J C Part Fields. 2012;72(12):2251. doi: 10.1140/epjc/s10052-012-2251-3. Epub 2012 Dec 14.

Abstract

A measurement is presented of the relative prompt production rate of χc2 and χc1 with 4.6 fb-1 of data collected by the CMS experiment at the LHC in pp collisions at [Formula: see text]. The two states are measured via their radiative decays χc→J/ψ+γ, with the photon converting into an e+e- pair for J/ψ rapidity |y(J/ψ)|<1.0 and photon transverse momentum pT(γ)>0.5 GeV/c. The measurement is given for six intervals of pT(J/ψ) between 7 and 25 GeV/c. The results are compared to theoretical predictions.