The enhancement of v4 in nuclear collisions at the highest densities signals a first-order phase transition

Abstract

The beam energy dependence of v 4 (the quadrupole moment of the transverse radial flow) is sensitive to the nuclear equation of state (EoS) in mid-central Au + Au collisions at the energy range of 3 < √ s N N < 30 GeV, which is investigated within the hadronic transport model JAM. Different equations of state, namely, a free hadron gas, a first-order phase transition and a crossover are compared. An enhancement of v 4 at √ s N N ≈ 6 GeV is predicted for an EoS with a first-order phase transition. This enhanced v 4 flow is driven by both the enhancement of v 2 as well as the positive contribution to v 4 from the squeeze-out of spectator particles which turn into participants due to the admixture of the strong collective flow in the shocked, compressed nuclear matter.arXiv:1809.04237v1 [nucl-th]

JAM: an event generator for high energy nuclear collisions

“…[20]. Furthermore, it is recently shown that v 4 is also enhanced by the softening [39]. An interesting feature of the enhancement of v 4 is that v 4 is positive for the out-of-plane emission in contrast to the v 2 .…”

Anisotropic flow of charged and identified hadrons at FAIR energies and its dependence on the nuclear equation of state

“…Results available at RHIC [63][64][65][66] , over a range of beam energies studied in min-bias Au + Au collisions. In [38], an attempt has been made to study this ratio using JAM model. In Fig 21, we show this ratio as function of beam energy (E Lab ).…”

“…According to recent hydrodynamical predictions [35], v 4 encodes an important information on the underlying collision dynamics. Recently [38], the beam energy dependence of v 4 was studied using microscopic transport model JAM [17].…”

Probing criticality with deep learning in relativistic heavy-ion collisions

“…Many theoretical and experimental devoted to locate the CP [11,12]. One avenue is to classify the smooth crossover and first order phase transition using the information from the final state particle spectra and collective flow [13][14][15][16][17][18][19][20][21][22][23][24][25]. This method looks for the consequences of the softening of the equation of state since the pressure gradients are much smaller in a medium with a first order phase transition than a crossover phase transition, which leads to slower fluid acceleration and smaller transverse momenta of final state particles.…”