Measurement of the Polarizations of Prompt and Non-Prompt 𝐽/𝜓 and ψ(2S) Mesons Produced in PP Collisions at √s = 13 TeV

Physics Letters B 2024
Kārlis Dreimanis, Antra Gaile, Guntis Pikurs, Andris Potrebko, Markus Seidel, Dimitrios Sidiropoulos Kontos, CMS Collaboration

The polarizations of prompt and non-prompt J/ψ and ψ(2S) mesons are measured in proton-proton collisions at s=13 TeV, using data samples collected by the CMS experiment in 2017 and 2018, corresponding to a total integrated luminosity of 103.3fb−1. Based on the analysis of the dimuon decay angular distributions in the helicity frame, the polar anisotropy, λϑ, is measured as a function of the transverse momentum, pT, of the charmonium states, in the 25–120 and 20–100 GeV ranges for the [Formula presented] and ψ(2S), respectively. The non-prompt polarizations agree with predictions based on the hypothesis that, for pT≳25GeV, the non-prompt [Formula presented] and ψ(2S) are predominantly produced in two-body B meson decays. The prompt results clearly exclude strong transverse polarizations, even for pT exceeding 30 times the [Formula presented] mass, where λϑ tends to an asymptotic value around 0.3. Taken together with previous measurements, by CMS and LHCb at s=7 TeV, the prompt polarizations show a significant variation with pT, at low pT.

Atslēgas vārdi
CMS | Quarkonium polarization | Quarkonium production
DOI
10.1016/j.physletb.2024.139044
Hipersaite
https://www.sciencedirect.com/science/article/pii/S0370269324006026

The CMS Collaboration, Hayrapetyan, A., Dreimanis, K., Gaile, A., Pikurs, G., Potrebko, A., Seidel, M., Sidiropoulos Kontos, D., ... [et al.] Measurement of the Polarizations of Prompt and Non-Prompt 𝐽/𝜓 and ψ(2S) Mesons Produced in PP Collisions at √s = 13 TeV. Physics Letters B, 2024, Vol. 858, Article number 139044. ISSN 0370-2693. e-ISSN 1873-2445. Pieejams: doi:10.1016/j.physletb.2024.139044

Publikācijas valoda
English (en)