Heavy ion event generator HYDJET++ (HYDrodynamics plus JETs)

TL;DR

HYDJET++ is a comprehensive Monte-Carlo event generator that simulates relativistic heavy ion collisions by combining hydrodynamic soft processes with hard multi-parton fragmentation, enabling detailed studies across various collider energies.

Contribution

This paper introduces HYDJET++, an advanced event generator integrating hydrodynamics and jet fragmentation for heavy ion collision simulations.

Findings

Simulates soft and hard components of heavy ion collisions.

Includes flow effects and resonance decays.

Applicable across multiple collider energy ranges.

Abstract

HYDJET++ is a Monte-Carlo event generator for simulation of relativistic heavy ion AA collisions considered as a superposition of the soft, hydro-type state and the hard state resulting from multi-parton fragmentation. This model is the development and continuation of HYDJET event generator (Lokhtin & Snigirev, 2006, EPJC, 45, 211). The main program is written in the object-oriented C++ language under the ROOT environment. The hard part of HYDJET++ is identical to the hard part of Fortran-written HYDJET and it is included in the generator structure as a separate directory. The soft part of HYDJET++ event is the "thermal" hadronic state generated on the chemical and thermal freeze-out hypersurfaces obtained from the parameterization of relativistic hydrodynamics with preset freeze-out conditions. It includes the longitudinal, radial and elliptic flow effects and the decays of hadronic resonances. The corresponding fast Monte-Carlo simulation procedure, C++ code FAST MC (Amelin et al., 2006, PRC, 74, 064901; 2008, PRC, 77, 014903) is adapted to HYDJET++. It is designed for studying the multi-particle production in a wide energy range of heavy ion experimental facilities: from FAIR and NICA to RHIC and LHC.