Measurement of higher cumulants of net-charge multiplicity distributions in Au+Au collisions at sNN=7.7–200GeV

Le résumé fourni par la source

We report the measurement of cumulants (${C}_{n},n=1,...,4$) of the net-charge distributions measured within pseudorapidity ($|\ensuremath{\eta}|<\phantom{\rule{0.28em}{0ex}}0.35$) in $\mathrm{Au}\phantom{\rule{0.16em}{0ex}}+\mathrm{Au}$ collisions at $\sqrt{{s}_{{}_{NN}}}=7.7--200\phantom{\rule{0.28em}{0ex}}\mathrm{GeV}$ with the PHENIX experiment at the Relativistic Heavy Ion Collider. The ratios of cumulants (e.g., ${C}_{1}/{C}_{2}, {C}_{3}/{C}_{1}$) of the net-charge distributions, which can be related to volume independent susceptibility ratios, are studied as a function of centrality and energy. These quantities are important to understand the quantum-chromodynamics phase diagram and possible existence of a critical end point. The measured values are very well described by expectation from negative binomial distributions. We do not observe any nonmonotonic behavior in the ratios of the cumulants as a function of collision energy. The measured values of ${C}_{1}/{C}_{2}$ and ${C}_{3}/{C}_{1}$ can be directly compared to lattice quantum-chromodynamics calculations and thus allow extraction of both the chemical freeze-out temperature and the baryon chemical potential at each center-of-mass energy. The extracted baryon chemical potentials are in excellent agreement with a thermal-statistical analysis model.

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