GLISSANDO 3: GLauber Initial-State Simulation AND mOre, ver. 3

Abstract

We present ver. 3 of GLISSANDO, a versatile Monte-Carlo generator for Glauber-like models of the initial stages of ultra-relativistic heavy-ion collisions. The present version incorporates the wounded parton model, which is phenomenologically successful in reproducing multiplicities of particle production at the RHIC and the LHC. Within this model, one can study the nucleon substructure fluctuation effects, recently explored in p-A collisions. In addition, the code includes the possibility of investigating collisions of light nuclei, such as 3He and 3H, or the α-clustered 7,9Be, 12C, and 16O, where the deformation of the intrinsic wave function influences the transverse shape of the initial state. The current version, being down-compatible, retains the functionality of the previous releases, such as incorporation of various variants of Glauber-like models, a smooth NN inelasticity profile in the impact parameter obtained from a parameterization of experimental data, fluctuating strength of the entropy deposition, or realistic nuclear distributions of heavy nuclei with deformation. The code can provide output in the format containing the event-by-event source location, which may be further used in modeling the intermediate evolution phase, e.g., with hydrodynamics or transport models. The interface is simplified, such that in the control input file the user may supply only the very basic information, such as the collision energy, the mass numbers of the colliding nuclei, and the model type. GLISSANDO 3 is integrated with the CERN ROOT platform. The package includes numerous illustrative and useful ROOT scripts to compute and plot various results. Program summaryProgram Title:GLISSANDO 3 ver. 3.42Program Files doi:http://dx.doi.org/10.17632/yfrzxkrcvr.1Licensing provisions: CC By 4.0Programming language:C++ with the ROOT librariesNature of problem: The code implements in a versatile way the Glauber modeling of the initial stages of ultra-relativistic nuclear collisions, including the wounded nucleon and wounded quark models, with possible admixture of binary collisions. A state-of-the art inelastic nucleon–nucleon collision profile is implemented. A statistical distribution of the strength of the sources can be overlaid. The α clustered structure of light nuclei is built in.Solution method: Monte-Carlo simulation of nuclear collisions, analyzed off-line with numerous ROOT scripts. The software allows for a straightforward event-by-event analysis of eccentricity coefficients and their correlations, size fluctuations, or multiplicity distributions.Additional comments including restrictions and unusual features: The input may consist only of the model type, the mass numbers of the nuclei and the collision energy. The output can also be used as initial conditions for further hydrodynamic studies.