Fast hadron freeze-out generator

Abstract

We have developed a fast Monte Carlo procedure of hadron generation allowing one to study and analyze various observables for stable hadrons and hadron resonances produced in ultra-relativistic heavy ion collisions. Particle multiplicities are determined based on the concept of chemical freezeout. Particles can be generated on the chemical or thermal freeze-out hypersurface represented by a parameterization or a numerical solution of relativistic hydrodynamics with given initial conditions and equation of state. Besides standard space-like sectors associated with the volume decay, the hypersurface may also include non-space-like sectors related to the emission from the surface of expanding system. For comparison with other models and experimental data we demonstrate the results based on the standard parameterizations of the hadron freeze-out hypersurface and flow velocity profile under the assumption of a common chemical and thermal freeze-out. The C++ generator code is written under the ROOT framework and is available for public use at

Transverse momentum distribution and elliptic flow of charged hadrons in $$U+U$$ U + U collisions at $$\sqrt{s_{NN}}=193$$ s NN = 193 GeV using HYDJET++

“…The soft part of HYDJET++ is the thermal hadronic state generated on the chemical and thermal freeze-out hypersurface obtained from the parameterization of relativistic hydrodynamics with a given freeze-out condition [42,43]. The first and foremost modification which we have done in soft part is to change the nuclear density profile function for deformed uranium nucleus as discussed in above section.…”

Is hexagonal flow ν6just a superposition of elliptic ν2and triangular ν3flows?

“…The description of the event generator HYDJET++ (HYDrodynamics with JETs) can be found elsewhere [12][13][14]. Recall briefly, that parametrized hydrodynamics is employed [13] to generate soft part of particle spectra, including hadron yields, femtoscopy correlations and differential elliptic flow.…”

“…Recall briefly, that parametrized hydrodynamics is employed [13] to generate soft part of particle spectra, including hadron yields, femtoscopy correlations and differential elliptic flow. In the hard sector the model accounts for radiative and collisional losses [14] for partons traversing hot and dense nuclear matter.…”

Anisotropic flow fluctuations in Pb+Pb collisions at LHC

“…Detailed description of the event generator HYDJET++, which merges thermalized hydro-like state with separated chemical and thermal freeze-outs [24,25] with in-medium fragmentation of hard partons [26], can be found elsewhere [12]. The fine tuning of free model parameters was done in [13] to match the bulk observables in lead-lead collisions at LHC.…”