Measurement of an Excess in the Yield of J/psi at Very Low p(T) in Pb-Pb Collisions at root s(NN)=2.76 TeV

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378271%3A_____%2F16%3A00462431" target="_blank" >RIV/68378271:_____/16:00462431 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/61389005:_____/16:00462431 RIV/68407700:21340/16:00301053

Výsledek na webu

<a href="http://dx.doi.org/10.1103/PhysRevLett.116.222301" target="_blank" >http://dx.doi.org/10.1103/PhysRevLett.116.222301</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevLett.116.222301" target="_blank" >10.1103/PhysRevLett.116.222301</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Measurement of an Excess in the Yield of J/psi at Very Low p(T) in Pb-Pb Collisions at root s(NN)=2.76 TeV

Popis výsledku v původním jazyce

We report on the first measurement of an excess in the yield of J/psi at very low transverse momentum (pT < 0.3 GeV/c) in peripheral hadronic Pb-Pb collisions at root s(NN) = 2.76 TeV, performed by ALICE at the CERN LHC. Remarkably, the measured nuclear modification factor of J/psi in the rapidity range 2.5 < y < 4 reaches about 7 (2) in the p(T) range 0-0.3 GeV/c in the 70%-90% (50%-70%) centrality class. The J/psi production cross section associated with the observed excess is obtained under the hypothesis that coherent photoproduction of J/psi is the underlying physics mechanism. If confirmed, the observation of J/psi coherent photoproduction in Pb-Pb collisions at impact parameters smaller than twice the nuclear radius opens new theoretical and experimental challenges and opportunities. In particular, coherent photoproduction accompanying hadronic collisions may provide insight into the dynamics of photoproduction and nuclear reactions, as well as become a novel probe of the quark-gluon plasma.

Název v anglickém jazyce

Measurement of an Excess in the Yield of J/psi at Very Low p(T) in Pb-Pb Collisions at root s(NN)=2.76 TeV

Popis výsledku anglicky

We report on the first measurement of an excess in the yield of J/psi at very low transverse momentum (pT < 0.3 GeV/c) in peripheral hadronic Pb-Pb collisions at root s(NN) = 2.76 TeV, performed by ALICE at the CERN LHC. Remarkably, the measured nuclear modification factor of J/psi in the rapidity range 2.5 < y < 4 reaches about 7 (2) in the p(T) range 0-0.3 GeV/c in the 70%-90% (50%-70%) centrality class. The J/psi production cross section associated with the observed excess is obtained under the hypothesis that coherent photoproduction of J/psi is the underlying physics mechanism. If confirmed, the observation of J/psi coherent photoproduction in Pb-Pb collisions at impact parameters smaller than twice the nuclear radius opens new theoretical and experimental challenges and opportunities. In particular, coherent photoproduction accompanying hadronic collisions may provide insight into the dynamics of photoproduction and nuclear reactions, as well as become a novel probe of the quark-gluon plasma.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

BF - Elementární částice a fyzika vysokých energií

OECD FORD obor

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Projekt

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

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2016

Kód důvěrnosti údajů

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

Název periodika

Physical Review Letters

ISSN

0031-9007

e-ISSN

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Svazek periodika

116

Číslo periodika v rámci svazku

22

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

13

Strana od-do

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Kód UT WoS článku

000377018100005

EID výsledku v databázi Scopus

2-s2.0-84973450046