Generalized susceptibilities of net-baryon number based on the 3-dimensional Ising universality class

Abstract

Assuming the equilibrium of the QCD system, we have investigated the critical behavior of sixth-, eighth- and tenth-order susceptibilities of net-baryon number, through mapping the results in the three-dimensional Ising model to that of QCD. Both the leading critical contribution as well as sub-leading critical contribution from the Ising model are discussed. When considering only the leading critical contribution, the density plots for susceptibilities of the same order demonstrate a consistent general pattern independent on values of mapping parameters. As the critical point is approached from the crossover side, a negative dip followed by a positive peak is observed in the $\mu_B$ dependence of the three different orders of susceptibilities. When sub-leading critical contribution is taken into account, modifications become apparent in the density plots of the susceptibilities. The emergence of negative dips in the $\mu_B$ dependence of the susceptibilities is not an absolute phenomenon, while the positive peak structure is a more robust feature of the critical point.