Baryon Number Probability Distribution In Heavy Ion Collisions

The probability distribution of the net baryon number is investigated within the function-al renormalization group(FRG)approach for finite temperature and density.As a nonpertur-bative continuum field approach,FRG encodes quantum fluctuations of different wavelengths successively,through the running of RG scale k from the UV to IR regime with the evolution of renormalization group flow equation.We find that the Roberge-Weiss periodicity related to the Z(3)symmetry of the gluon fields results directly in that,states of the net baryon number N_B=N±1/3 with N?Z are prohibited,and only those of N_B=N are possible.By em-ploying the probability distribution of the net baryon number,we also compute the cumulants of the baryon number distribution,which are found to be well consistent with those obtained from the generalized susceptibilities.By combining Skellam distribution and Gaussian distribution,get an approximate baryon distribution function,whose cumulants is agree with the first four oder cumulants obtained from the generalized susceptibilities.The fit distribution functions a-gree well with FRG approach distribution functions.A question about the relation between the color confinement and the probability distribution of net baryon number is put forward:color confinement is still exist at high temperature,which is to be studied.