Measurement of J/psi and psi(2S) prompt double-differential cross sections in pp collisions at sqrt(s) = 7 TeV

TL;DR

This paper reports the measurement of prompt J/psi and psi(2S) meson production cross sections at 7 TeV in proton-proton collisions, extending to the highest transverse momenta ever measured, providing detailed insights into quarkonium production.

Contribution

It presents the first measurement of prompt J/psi and psi(2S) double-differential cross sections up to 120 and 100 GeV in pp collisions at 7 TeV, using a novel two-dimensional analysis method.

Findings

Cross sections measured up to 120 GeV for J/psi and 100 GeV for psi(2S).

The psi(2S) to J/psi cross section ratio is provided for 10 < pt < 100 GeV.

Results extend the kinematic range of quarkonium production measurements.

Abstract

The double-differential cross sections of promptly produced J/psi and psi(2S) mesons are measured in pp collisions at sqrt(s) = 7 TeV, as a function of transverse momentum pt and absolute rapidity abs(y). The analysis uses J/psi and psi(2S) dimuon samples collected by CMS, corresponding to integrated luminosities of 4.55 and 4.90 inverse femtobarns, respectively. The results are based on a two-dimensional analysis of the dimuon invariant mass and decay length, and extend to pt = 120 and 100 GeV for the J/psi and psi(2S), respectively, when integrated over the interval abs(y) < 1.2. The ratio of the psi(2S) to J/psi cross sections is also reported for abs(y) < 1.2, over the range 10 < pt < 100 GeV. These are the highest pt values for which the cross sections and ratio have been measured.