Observation of Excess J/psi Yield at Very Low Transverse Momenta in Au plus Au Collisions at root S-NN =200 GeV and U+U Collisions at root S-NN =193 GeV

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389005%3A_____%2F19%3A00509904" target="_blank" >RIV/61389005:_____/19:00509904 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68407700:21340/19:00334357

Výsledek na webu

<a href="https://doi.org/10.1103/PhysRevLett.123.132302" target="_blank" >https://doi.org/10.1103/PhysRevLett.123.132302</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevLett.123.132302" target="_blank" >10.1103/PhysRevLett.123.132302</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Observation of Excess J/psi Yield at Very Low Transverse Momenta in Au plus Au Collisions at root S-NN =200 GeV and U+U Collisions at root S-NN =193 GeV

Popis výsledku v původním jazyce

We report on the first measurements of J/psi production at very low transverse momentum (p(T) < 0.2 GeV/c) in hadronic Au + Au collisions at root S-NN = 200 GeV and U + U collisions at ONN = 193 GeV. Remarkably, the inferred nuclear modification factor of J/psi at midrapidity in Au + Au (U + U) collisions reaches about 24 (52) for p(T) < 0.05 GeV/c in the 60%-80% collision centrality class. This noteworthy enhancement cannot be explained by hadronic production accompanied by cold and hot medium effects. In addition, the dN/dt distribution of J/psi for the very low p(T) range is presented for the first time. The distribution is consistent with that expected from the Au nucleus and shows a hint of interference. Comparison of the measurements to theoretical calculations of coherent production shows that the excess yield can be described reasonably well and reveals a partial disruption of coherent production in semicentral collisions, perhaps due to the violent hadronic interactions. Incorporating theoretical calculations, the results strongly suggest that the dramatic enhancement of J/psi yield observed at extremely low p(T) originates from coherent photon-nucleus interactions. In particular, coherently produced J/psi in violent hadronic collisions may provide a novel probe of the quark-gluon plasma.

Název v anglickém jazyce

Observation of Excess J/psi Yield at Very Low Transverse Momenta in Au plus Au Collisions at root S-NN =200 GeV and U+U Collisions at root S-NN =193 GeV

Popis výsledku anglicky

We report on the first measurements of J/psi production at very low transverse momentum (p(T) < 0.2 GeV/c) in hadronic Au + Au collisions at root S-NN = 200 GeV and U + U collisions at ONN = 193 GeV. Remarkably, the inferred nuclear modification factor of J/psi at midrapidity in Au + Au (U + U) collisions reaches about 24 (52) for p(T) < 0.05 GeV/c in the 60%-80% collision centrality class. This noteworthy enhancement cannot be explained by hadronic production accompanied by cold and hot medium effects. In addition, the dN/dt distribution of J/psi for the very low p(T) range is presented for the first time. The distribution is consistent with that expected from the Au nucleus and shows a hint of interference. Comparison of the measurements to theoretical calculations of coherent production shows that the excess yield can be described reasonably well and reveals a partial disruption of coherent production in semicentral collisions, perhaps due to the violent hadronic interactions. Incorporating theoretical calculations, the results strongly suggest that the dramatic enhancement of J/psi yield observed at extremely low p(T) originates from coherent photon-nucleus interactions. In particular, coherently produced J/psi in violent hadronic collisions may provide a novel probe of the quark-gluon plasma.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10303 - Particles and field physics

Projekt

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

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2019

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

—

Svazek periodika

123

Číslo periodika v rámci svazku

13

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

8

Strana od-do

132302

Kód UT WoS článku

000488270200018

EID výsledku v databázi Scopus

2-s2.0-85073061405