First measurement of coherent ρ0 photoproduction in ultra-peripheral Xe–Xe collisions at sNN=5.44 TeV

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21340%2F21%3A00352470" target="_blank" >RIV/68407700:21340/21:00352470 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1016/j.physletb.2021.136481" target="_blank" >https://doi.org/10.1016/j.physletb.2021.136481</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.physletb.2021.136481" target="_blank" >10.1016/j.physletb.2021.136481</a>

Jazyk výsledku

angličtina

Název v původním jazyce

First measurement of coherent ρ0 photoproduction in ultra-peripheral Xe–Xe collisions at sNN=5.44 TeV

Popis výsledku v původním jazyce

The first measurement of the coherent photoproduction of ρ0 vector mesons in ultra-peripheral Xe–Xe collisions at sNN=5.44 TeV is presented. This result, together with previous HERA γp data and γ–Pb measurements from ALICE, describes the atomic number (A) dependence of this process, which is particularly sensitive to nuclear shadowing effects and to the approach to the black-disc limit of QCD at a semi-hard scale. The cross section of the Xe+Xe->ρ0+Xe+Xe process, measured at midrapidity through the decay channel ρ0->π+π-, is found to be dσ/dy=131.5±5.6(stat.)-16.9+17.5(syst.) mb. The ratio of the continuum to resonant contributions for the production of pion pairs is also measured. In addition, the fraction of events accompanied by electromagnetic dissociation of either one or both colliding nuclei is reported. The dependence on A of cross section for the coherent ρ0 photoproduction at a centre-of-mass energy per nucleon of the γA system of WγA,n=65 GeV is found to be consistent with a power-law behaviour σ(γA->ρ0A)∝Aα with a slope α=0.96±0.02(syst.). This slope signals important shadowing effects, but it is still far from the behaviour expected in the black-disc limit.

Název v anglickém jazyce

First measurement of coherent ρ0 photoproduction in ultra-peripheral Xe–Xe collisions at sNN=5.44 TeV

Popis výsledku anglicky

The first measurement of the coherent photoproduction of ρ0 vector mesons in ultra-peripheral Xe–Xe collisions at sNN=5.44 TeV is presented. This result, together with previous HERA γp data and γ–Pb measurements from ALICE, describes the atomic number (A) dependence of this process, which is particularly sensitive to nuclear shadowing effects and to the approach to the black-disc limit of QCD at a semi-hard scale. The cross section of the Xe+Xe->ρ0+Xe+Xe process, measured at midrapidity through the decay channel ρ0->π+π-, is found to be dσ/dy=131.5±5.6(stat.)-16.9+17.5(syst.) mb. The ratio of the continuum to resonant contributions for the production of pion pairs is also measured. In addition, the fraction of events accompanied by electromagnetic dissociation of either one or both colliding nuclei is reported. The dependence on A of cross section for the coherent ρ0 photoproduction at a centre-of-mass energy per nucleon of the γA system of WγA,n=65 GeV is found to be consistent with a power-law behaviour σ(γA->ρ0A)∝Aα with a slope α=0.96±0.02(syst.). This slope signals important shadowing effects, but it is still far from the behaviour expected in the black-disc limit.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10301 - Atomic, molecular and chemical physics (physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect)

Projekt

<a href="/cs/project/EF16_019%2F0000778" target="_blank" >EF16_019/0000778: Centrum pokročilých aplikovaných přírodních věd</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2021

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

820

Číslo periodika v rámci svazku

Sep

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

12

Strana od-do

—

Kód UT WoS článku

000713101800035

EID výsledku v databázi Scopus

2-s2.0-85111237259