Measurement of psi (2S) production cross-sections in proton-proton collisions at v s=7 and 13 TeV

Abstract

The cross-sections of ψ(2S) meson production in proton-proton collisions at √ s = 13 TeV are measured with a data sample collected by the LHCb detector corresponding to an integrated luminosity of 275 pb−1. The production cross-sections for prompt ψ(2S) mesons and those for ψ(2S) mesons from b-hadron decays (ψ(2S)-from-b) are determined as functions of the transverse momentum, pT, and the rapidity, y, of the ψ(2S) meson in the kinematic range 2 < pT < 20 GeV/c and 2.0 < y < 4.5. The production cross-sections integrated over this kinematic region are σ(prompt ψ(2S), 13 TeV) = 1.430 ± 0.005 (stat) ± 0.099 (syst) μb, σ(ψ(2S)-from-b, 13 TeV) = 0.426 ± 0.002 (stat) ± 0.030 (syst) μb. A new measurement of ψ(2S) production cross-sections in pp collisions at √ s = 7 TeV is also performed using data collected in 2011, corresponding to an integrated luminosity of 614 pb−1. The integrated production cross-sections in the kinematic range 3.5 < pT < 14 GeV/c and 2.0 < y < 4.5 are σ(prompt ψ(2S),7 TeV) = 0.471 ± 0.001 (stat) ± 0.025 (syst) μb, σ(ψ(2S)-from-b,7 TeV) = 0.126 ± 0.001 (stat) ± 0.008 (syst) μb. All results show reasonable agreement with theoretical calculations.