Nonmonotonic Energy Dependence of Net-Proton Number Fluctuations

作者：Adam, J.; Adamczyk, L.; Adams, J. R.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I; Anderson, D. M.; Aparin, A.; Aschenauer, E. C.; Ashraf, M. U.; Atetalla, F. G.; Attri, A.; Averichev, G. S.; Bairathi, V; Barish, K.; Behera, A.; Bellwied, R.; Bhasin, A.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Brandenburg, J. D.; Brandin, A., V; Butterworth, J.; Caines, H.; Sanchez, M. Calderon de la Barca; Cebra, D.; Chakaberia, I; Chaloupka, P.; Chan, B. K.

来源：Physical Review Letters, 2021, 126(9): 092301.

DOI：10.1103/PhysRevLett.126.092301

Nonmonotonic variation with collision energy (root s(NN)) of the moments of the net-baryon number distribution in heavy-ion collisions, related to the correlation length and the susceptibilities of the system, is suggested as a signature for the quantum chromodynamics critical point. We report the first evidence of a nonmonotonic variation in the kurtosis times variance of the net-proton number (proxy for net-baryon number) distribution as a function of root s(NN) with 3.1 sigma significance for head-on (central) gold-on-gold (Au + Au) collisions measured solenoidal tracker at Relativistic Heavy Ion Collider. Data in noncentral Au + Au collisions and models of heavy-ion collisions without a critical point show a monotonic variation as a function of root s(NN.)