Hadronization during quark-gluon plasma phase transition

The hadron multiplicity distributions and factorial moments are studied in the framework of Landau theory of phase transitions. The factorial moments show a scaling law with a scaling exponent nu which characterizes the intermittency properties of the hadron phase for T<T-c (or T-t) where T-c (or T-t) is the transition temperature for second (or first) order transition. The scaling exponent nu is weakly dependent on the free energy parameters as well as on temperature. It is shown that nu remains practically constant in the hadron phase for which T<T-c or T<T-t whether the transition is second order or first order of second kind where the free energy expansion includes cubic term. This universality in the scaling exponent is also maintained above T-c over a wide range of temperature even if the transition is strongly first order of first kind where the free energy expansion has only even order coefficients, except around the critical temperature T-t where T-t>T-c. Therefore, the scaling exponent nu is rather more universal and only indicates the presence of a possible phase transition. It is further shown that the hadron multiplicity distribution is quite sensitive to the free energy parameters. The study of hadron multiplicity distribution at various resolution or bin size reveals more information about the dynamics of the phase transition. The calculated hadron multiplicity distributions are also compared with the negative binomial distribution, often used to explain the experimental multiplicity distributions.