Soft and hard scales of the transverse momentum distribution in the color string percolation model

Abstract

AbstractIn color string models, the transverse momentum distribution (TMD) is obtained through the convolution of the Schwinger mechanism with the string tension fluctuations distribution. Considering aq-Gaussian distribution for these fluctuations, the TMD becomes a hypergeometric confluent function that adequately reproduces the characteristic scales at low and highpTvalues. In this approach, the hard scale of the TMD is a consequence of considering a heavy-tailed distribution for the string tension fluctuations whose width rises ass, multiplicity or centrality increases. In this paper, we introduce broader information of the TMD in the color string percolation model by determining the color suppression factor, which now also depends on the parameters of theq-Gaussian. To this end, we analyze the reported data on pp and AA collisions at different center of mass energies, multiplicities, and centralities. In particular, for minimum bias pp collisions, we found that theq-Gaussian parameters and the effective temperature are monotonically increasing functions of the center of mass energy. Similar results are found for AA collisions as a function of the centrality at fixeds. We summarize these results in a phase diagram that indicates theq-Gaussian parameters region allowing the quark–gluon plasma formation.