Measurement of J/ψ production cross-sections in pp collisions at s√ = 5 TeV

Journal of High Energy Physics. 2021. Article 181.

The LHCb c., Boldyrev A., Derkach D., Hushchyn M., Karpov M., Maevskiy A., Ratnikov F., Ryzhikov A., Ustyuzhanin A., Arzymatov K., Belavin V., Borisyak M., Philippov A., Popov S.

The production cross-sections of J/ψ mesons in proton-proton collisions at a centre-of-mass energy of 𝑠√s = 5 TeV are measured using a data sample corresponding to an integrated luminosity of 9.13 ± 0.18 pb−1, collected by the LHCb experiment. The cross-sections are measured differentially as a function of transverse momentum, pT, and rapidity, y, and separately for J/ψ mesons produced promptly and from beauty hadron decays (nonprompt). With the assumption of unpolarised J/ψ mesons, the production cross-sections integrated over the kinematic range 0 < pT < 20 GeV/c and 2.0 < y < 4.5 are

𝜎prompt 𝐽/𝜓=8.154±0.010±0.283 μb,𝜎nonprompt 𝐽/𝜓=0.820±0.003±0.034 μb,σprompt J/ψ=8.154±0.010±0.283 μb,σnonprompt J/ψ=0.820±0.003±0.034 μb,

where the first uncertainties are statistical and the second systematic. These cross-sections are compared with those at 𝑠√s = 8 TeV and 13 TeV, and are used to update the measurement of the nuclear modification factor in proton-lead collisions for J/ψ mesons at a centre-of-mass energy per nucleon pair of 𝑠NN‾‾‾‾√sNN = 5 TeV. The results are compared with theoretical predictions.

Keywords: анализ данных, data analysis, high energy physics, физика высоких энергий

Publication based on the results of: Machine learning to check and improve the quality of data collected at the Large Hadron Collider and other particle physics experiments (2021)