Equation of state dependence of Mach cone-like structures in Au+Au collisions

Abstract

In jet quenching, a hard QCD parton, before fragmenting into a jet of hadrons, deposits a fraction of its energy in the medium. As the parton moves nearly with speed of light, much greater that the speed of sound of the medium, quenching jet can generate Mach shock wave. We have examined the possibility of Mach shock wave formation due to jet quenching. Assuming that the deposited energy quickly thermalize, we simulate the hydrodynamic evolution of the QGP fluid with a quenching jet and subsequent particle production. Angular distribution of pions, averaged over all the jet trajectories, resembles 'conical flow' due to Mach shock wave formation. However, speed of sound dependence of the simulated Mach angles are at variance with that due to shock wave formation in a static medium or in a medium with finite velocity.

On Pseudorapidity Distribution and Speed of Sound in High Energy Heavy Ion Collisions Based on a New Revised Landau Hydrodynamic Model

“…At the same time, the rapidity and pseudorapidity distributions are strictly distinguished, which avoids the errors caused by non-division or inapposite conversion. Comparing with the results of the four-source picture in our previous work, larger 2 which is for zero shear modulus and massless particles, where D denotes the dimensionality of space [38,39], we know that 2 1 3 s c  for the ideal hadronic gas [40][41][42][43][44][45][46][47][48][49] which has D=3 in the reaction volume and 2 1 2 s c  [39] for D=2 which corresponds to the ideal QGP liquid phase in the reaction plane. The present work shows that the target/projectile sources remain in the state of hadronic gas in all cases and the central source undergoes through the phase transition from the hadronic gas to the QGP liquid in most cases.…”

On Distributions of Emission Sources and Speed-of-Sound in Proton-Proton (Proton-Antiproton) Collisions

“…for massless particles [62,63]. Then, the value 2 1 3 s c  for D=3 corresponds to the ideal gas state (large mean free path) of hadronic matter investigated by different groups in the past [64][65][66][67][68] and more recently [69][70][71][72][73]; instead, 2 1 2 s c  for D=2 corresponds to the ideal liquid state (small mean free path) investigated by Buchbinder et al [63]. The present work seems to suggest that the target and projectile sources formed in proton-proton (proton-antiproton) collisions at 0.2 13 s   TeV stay in the gas-like state and the central source stays in a liquid-like state.…”

On pseudorapidity distribution in p-Pb and Xe–Xe collisions at high energy based on the three-source Landau hydrodynamic model

“…This is consistent with the conclusion of our previous wo rk. According to the literature [17] and literature [18], we know that for zero-shear modulus and massless particles have a relation between 2 implies that the value of D is 3, this result expresses the properties of the matter is the ideal hadronic gas [19][20][21][22][23]. 2 12 s c  means the value of D is 2, this result shows the properties of the matter is the ideal QGP liquid [18].…”