Multiplicity difference correlators under first-order QGP phase transition

Abstract

The multiplicity difference correlators between two well-separated bins in high-energy heavy-ion collisions are studied as a means to detect evidence of a first-order quark-hadron phase transition. Analytical expressions for the scaled factorial moments of multiplicity difference distribution are obtained for small bin size δ with mean multiplicity in the bin s ≤ 1.0 within Ginzburg-Landau description. The scaling behaviors between the moments are still valid, though they behave completely different from the so-called intermittency patterns. A universal exponent γ = 1.4066 is given to describe the dynamical fluctuations in the phase transition in small δ limit.The theoretical study of fluctuations in quark-hadron phase transition has been suggested for several years [1] . The first motivation came from the quantitatively different results in Monte Carlo simulations [2] on intermittency for pp collisions without phase transition from those theoretical predictions with the onset of phase transition [1] . Since then, multiplicity fluctuations are studied with phase transitions of second-order [3] and first-order [4−6] within GinzburgLandau model, and it is regarded as a possible means to reveal some features for the phase transition. Most of these works give the violation of the intermittency patterns but show remarkable scaling behaviors between F q and F 2 , and there seems to exist a universal exponent ν [1,3,6] . It is suggested that the exponent ν can be used as a useful diagnostic tool to detect the formation of QGP. In [4,5] ln F q are studied analytically for first-order phase transition and are expanded as power series of δ 1/3 , and it is shown that the set of experimentally fitted coefficients for δ

Scaling behaviour of the multiplicity distribution under first-order quark-hadron phase transition

“…A similar relation between D q and F q is also true in the small s limit. In these limiting cases, the scaling of D q is equivalent to that for the scaled factorial moments F q , and one can get the exponent γ =1.4066 for large − ln s [15] or large |a|. This exponent is a little different from those obtained from the study of the factorial moments for both first-and second-order phase transitions [9,10,13,14] and of the multiplicity difference correlators for second-order phase transition [16].…”

Effect of long-range correlation on scaling behavior of normalized factorial moments for the first-order phase

“…The moments of multiplicity difference has been investigated in Refs. [31][32][33][34], assuming that the fluctuations in the two bins are uncorrelated.…”

“…Ginzburg Landau theory is a phenomenological model theory initially describing superconductors without examining their microscopic properties [19,20]. Over the past two decades, this model has been used to study multiplicity fluctuations about first-and second-order phase transitions [21][22][23][24][25][26][27][28][29][30][31][32][33], and regarded as a possible means to reveal some features of phase transitions. Ref.…”