J/ψ production at low pT in Au + Au and Cu + Cu collisions at sNN=200 GeV with the STAR detector

Le résumé fourni par la source

The $J/\ensuremath{\psi}$ ${p}_{T}$ spectrum and nuclear modification factor (${R}_{\mathit{AA}}$) are reported for ${p}_{T}<5\phantom{\rule{4pt}{0ex}}\mathrm{GeV}/c$ and $|y|<1$ from 0% to 60% central $\mathrm{Au}+\mathrm{Au}$ and $\mathrm{Cu}+\mathrm{Cu}$ collisions at $\sqrt{{s}_{NN}}=200\phantom{\rule{4pt}{0ex}}\mathrm{GeV}$ at STAR. A significant suppression of ${p}_{T}$-integrated $J/\ensuremath{\psi}$ production is observed in central $\mathrm{Au}+\mathrm{Au}$ events. The $\mathrm{Cu}+\mathrm{Cu}$ data are consistent with no suppression, although the precision is limited by the available statistics. ${R}_{\mathit{AA}}$ in $\mathrm{Au}+\mathrm{Au}$ collisions exhibits a strong suppression at low transverse momentum and gradually increases with ${p}_{T}$. The data are compared to high-${p}_{T}$ STAR results and previously published BNL Relativistic Heavy Ion Collider results. Comparing with model calculations, it is found that the invariant yields at low ${p}_{T}$ are significantly above hydrodynamic flow predictions but are consistent with models that include color screening and regeneration.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.