First polarisation measurement of coherently photoproduced J/ψ in ultra-peripheral Pb-Pb collisions at √sNN=5.02 TeV

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389005%3A_____%2F25%3A00637019" target="_blank" >RIV/61389005:_____/25:00637019 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68378271:_____/25:00637019

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0370269325002278" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0370269325002278</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.physletb.2025.139466" target="_blank" >10.1016/j.physletb.2025.139466</a>

Jazyk výsledku

angličtina

Název v původním jazyce

First polarisation measurement of coherently photoproduced J/ψ in ultra-peripheral Pb-Pb collisions at √sNN=5.02 TeV

Popis výsledku v původním jazyce

The first measurement of the polarisation of coherently photoproduced J/psi mesons in ultra-peripheral Pb-Pb collisions, using data at root s(NN) = 5.02 TeV, is presented. The J/psi meson is measured via its dimuon decay channel in the forward rapidity interval -4.0 < y < -2.5 using the ALICE detector at the CERN LHC. An event sample corresponding to an integrated luminosity of 750 mu b(-1) +/- 5% (syst) is analysed. Hadronic activity is highly suppressed since the interaction is mediated by a photon. The polar and azimuthal angle distributions of the decay muons are measured, and the polarisation parameters lambda(theta), lambda(phi), lambda(theta phi) are extracted. The analysis is carried out in the helicity frame. The results are found to be consistent with a transversely polarised J/psi. These values are compared with previous measurements by the H1 and ZEUS experiments. The polarisation parameters of coherent J/psi photoproduction in Pb-Pb collisions are found to be consistent with the s-channel helicity conservation hypothesis.

Název v anglickém jazyce

First polarisation measurement of coherently photoproduced J/ψ in ultra-peripheral Pb-Pb collisions at √sNN=5.02 TeV

Popis výsledku anglicky

The first measurement of the polarisation of coherently photoproduced J/psi mesons in ultra-peripheral Pb-Pb collisions, using data at root s(NN) = 5.02 TeV, is presented. The J/psi meson is measured via its dimuon decay channel in the forward rapidity interval -4.0 < y < -2.5 using the ALICE detector at the CERN LHC. An event sample corresponding to an integrated luminosity of 750 mu b(-1) +/- 5% (syst) is analysed. Hadronic activity is highly suppressed since the interaction is mediated by a photon. The polar and azimuthal angle distributions of the decay muons are measured, and the polarisation parameters lambda(theta), lambda(phi), lambda(theta phi) are extracted. The analysis is carried out in the helicity frame. The results are found to be consistent with a transversely polarised J/psi. These values are compared with previous measurements by the H1 and ZEUS experiments. The polarisation parameters of coherent J/psi photoproduction in Pb-Pb collisions are found to be consistent with the s-channel helicity conservation hypothesis.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10304 - Nuclear physics

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physics Letters. B

ISSN

0370-2693

e-ISSN

1873-2445

Svazek periodika

865

Číslo periodika v rámci svazku

June

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

12

Strana od-do

139466

Kód UT WoS článku

001498299200001

EID výsledku v databázi Scopus

2-s2.0-105003226807