The Sixth-Order Cumulants of Net-proton Multiplicity Distributions Measured in STAR at RHIC

The ratios of different-order cumulants of conserved quantities have become important observables for probing the Quantum Chromodynamics (QCD) phase diagram, due to their sensitivity to the correlation length of the system near the phase transition. It has been predicted that a sixth-order cumulant may change its sign if the freeze-out curve is close to the phase transition temperature. In this paper, preliminary results are presented on the ratios of sixth-order to second-order cumulants image of the net-proton multiplicity distributions at mid-rapidity image measured in Au + Au collisions at image.