Study of Proton, Deuteron, and Triton at 54.4 GeV

Abstract

Transverse momentum spectra of proton, deuteron, and triton in gold-gold (Au-Au) collisions at 54.4 GeV are analyzed in different centrality bins by the blast wave model with Tsallis statistics. The model results are approximately in agreement with the experimental data measured by STAR Collaboration in special transverse momentum ranges. We extracted the kinetic freeze-out temperature, transverse flow velocity, and freeze-out volume from the transverse momentum spectra of the particles. It is observed that the kinetic freeze-out temperature is increasing from the central to peripheral collisions. However, the transverse flow velocity and freeze-out volume decrease from the central to peripheral collisions. The present work reveals the mass dependent kinetic freeze-out scenario and volume differential freeze-out scenario in collisions at STAR Collaboration. In addition, parameter q characterizes the degree of nonequilibrium of the produced system, and it increases from the central to peripheral collisions and increases with mass .

Analysis of kinetic freeze out temperature and transverse flow velocity in nucleus-nucleus and proton-proton collisions at same center of mass energy

“…At the same time, a negative correlation between T 0 and β T will also be obtained. Thus, this situation is in agreement with some references [10,42,55,64,65], but if for central collisions, one even uses an almost unchanging or slightly larger T 0 and a properly larger β T , an almost invariant or slightly increasing trend for T 0 from peripheral to central collisions can be obtained [7,15,56,63]. In order to show the flexibility in the extraction of T 0 and β T , this work has reported a decreasing trend for T 0 from central to peripheral collisions, and a positive correlation between T 0 and β T .…”

Observation of different scenarios in different temperatures in small and large collision systems

“…The difference in the two temperatures is due to the reason that they occur at two different process in the system evolution. Furthermore, it is also possible that the centrality dependence of the two types of temperatures is also different if one gets the increasing trend from central to peripheral for T 0 which is observed in our recent work [64,65]. In fact the trend dependence of T 0 is also an open question in high energy collisions because different literature give different trend.…”

Study of Kinetic Freeze-Out Parameters as a Function of Rapidity in pp Collisions at CERN SPS Energies

“…We can use Equation (1) for the fitting of p T spectra and extract the parameters T 0 , β T , and V. Equation ( 1) is applicable in only the soft p T (p T = 2-3 GeV/c) regime of the p T spectra and is valid for a narrow p T range. In the range of p T >3 GeV/c, a hard scattering process should be brought into consideration, which was studied in our previous studies [5,8,9,13,16,18].…”

“…In the literature, there are various kinetic freeze-out scenarios including single, double, triple, and multiple kinetic freeze-out scenarios [9][10][11][12][13][14]. In addition, there are various claims and dependencies of the kinetic freeze-out temperature on centrality [5][6][7][8][9][10]13,[15][16][17] and collision energy [2,3,10,18]. In our recent work, it was observed that the kinetic freeze-out temperature also depends on coalescence and isospin symmetry [19].…”