Coherent J/psi and psi ' photoproduction at midrapidity in ultra-peripheral Pb-Pb collisions at root s(NN)=5.02 TeV

0545623 - ÚJF 2022 RIV US eng J - Článek v odborném periodiku
Acharya, S. - Adamová, Dagmar - Bielčík, J. - Bielčíková, Jana - Broz, M. - Contreras, J. G. - Herman, T. - Horák, D. - Isakov, Artem - Křížek, Filip - Křížková Gajdošová, K. - Kushpil, Svetlana - Lavička, R. - Mareš, Jiří A. - Petráček, V. - Šafařík, K. - Šumbera, Michal - Torres, S. R. - Trzeciak, B. A. - Závada, Petr … celkem 999 autorů
Coherent J/psi and psi ' photoproduction at midrapidity in ultra-peripheral Pb-Pb collisions at root s(NN)=5.02 TeV.
European Physical Journal C. Roč. 81, č. 8 (2021), č. článku 712. ISSN 1434-6044. E-ISSN 1434-6052
Grant CEP: GA MŠMT(CZ) LTT17018; GA MŠMT(CZ) LM2018104
Výzkumná infrastruktura: CERN-CZ II - 90104
Institucionální podpora: RVO:68378271 ; RVO:61389005
Klíčová slova: ALICE collaboration * heavy ion collisions * heavy ion experiment
Obor OECD: Nuclear physics; Particles and field physics (FZU-D)
Impakt faktor: 4.994, rok: 2021
Způsob publikování: Open access
https://doi.org/10.1140/epjc/s10052-021-09437-6

The coherent photoproduction of J/psi and psi' mesons was measured in ultra-peripheral Pb-Pb collisions at a center-of-mass energy root s(NN) = 5.02 TeV with the ALICE detector. Charmonia are detected in the central rapidity region for events where the hadronic interactions are strongly suppressed. The J/psi is reconstructed using the dilepton (l(+)l(-)) and proton-antiproton decay channels, while for the psi' the dilepton and the l(+)l(-) pi(+)pi(-) decay channels are studied. The analysis is based on an event sample corresponding to an integrated luminosity of about 233 mu b(-1). The results are compared with theoretical models for coherent J/psi and psi' photoproduction. The coherent cross section is found to be in a good agreement with models incorporating moderate nuclear gluon shadowing of about 0.64 at a Bjorken-x of around 6 x 10(-4), such as the EPS09 parametrization, however none of the models is able to fully describe the rapidity dependence of the coherent J/psi cross section including ALICE measurements at forward rapidity. The ratio of psi' to J/psi coherent photoproduction cross sections was also measured and found to be consistent with the one for photoproduction off protons.
Trvalý link: http://hdl.handle.net/11104/0322300