PHENIX Collaboration

Tsallis-thermometer: a QGP indicator for large and small collisional systems

“…It was shown that the Tsallis -Pareto distributed transverse momentum leads to a total charged hadron multiplicity, that follows negative binomial distribution (NBD). This is also supported by experimental data, resulting in an NBD parameter k ∼ O(10) [116][117][118][119]133]. This observation results in an interpretation in which the fluctuations of the number of the produced particles, n is taken into account in a one dimensional relativistic gas [47]:…”

“…The temperature parameter T depends on the mass of the hadron, as is seen on figure 4a. This can be interpreted as the presence of radial flow, which increases the transverse momentum of the hadrons proportionally to their mass, therefore resulting in different temperatures instead of the originally common freeze-out temperature [53,124,125].…”

Analytic solution of multi-dimensional Schrödinger equation in hot and dense QCD media using the SUSYQM method

“…The studying of quarkonia at finite temperature is an essential tool for understanding the status of the matter (confined/confined) formed in the heavy ion collisions such in Refs. [24][25][26][27]. Many attempts have introduced to calculate the dissociation of binding energy of quarkonium in the quark-gluon plasma by applying lattice calculations [28][29][30][31] or non-relativistic quark models such as Schrödinger equation [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37].…”

Collision system size scan of collective flows in relativistic heavy-ion collisions

“…The properties of QGP are still an open question in heavy-ion collision community, which is not only depending on properties of QCD but also sensitive to initial geometry and dynamical fluctuations. The initial geometrical distribution and fluctuation can remain influence to observables at final state, such as collective flows [5][6][7][8][9][10], Hanbury-Brown-Twiss (HBT) correlation [11,12] and fluctuation [13]. Some theoretical works [14][15][16] presented flow/eccentricity analysis methods related to initial geometry fluctuations.…”

“…To understand these observables in experiments and QGP phase transition, there are also some open questions for small collision systems (such as C + C or O + O collisions) as well as large collision systems (such as Au + Au or Pb + Pb collisions), (1) how to understand transformation coefficient from initial geometry distribution or fluctuation to momentum distribution at final stage in hydrodynamical mechanism [20,[28][29][30]; (2) how to understand similar phenomena for some observables for small systems with high multiplicity and large systems [9,10,[31][32][33][34][35][36][37]; (3) does the matter created in different size of system undergo the similar dy-namical process and have similar viscosity [38,39]?, and the last two questions are closely related. Recently the small system experiments were proposed for RHIC-STAR [40] and LHC-ALICE [41] to study the initial geometry distribution and fluctuations effects on momentum distribution at final stage.…”