Measurement of the Sixth-Order Cumulant of Net-Proton Multiplicity Distributions in Au+Au Collisions at $\sqrt{s_{\rm NN}}=$ 27, 54.4, and 200 GeV at RHIC

Understand

According to first principle Lattice QCD calculations, the transition from quark-gluon plasma to hadronic matter is a smooth crossover in the region $\mu_{\rm B}\leq T_{c}$.

• In this range the ratio, $C_{6}/C_{2}$, of net-baryon distributions are predicted to be negative.
• In this paper, we report the first measurement of the midrapidity net-proton $C_{6}/C_{2}$ from 27, 54.4 and 200 GeV Au+Au collisions at RHIC.
• The dependence on collision centrality and kinematic acceptance in ($p_{T}$, $y$) are analyzed.