3DGlauber, MUSIC, iSS and Initial State Radiation - JETSCAPE/X-SCAPE GitHub Wiki

The new X-SCAPE will include 2 new modules i-Matter and 3DGlauber which work in concert with the existing Music and iSS modules as well as the Matter module and a new hard hadronization module:

• iMatter for the initial state radiation (ISR) of the hard partons
• 3DGlauber for modeling the initial energy profile of the bulk medium
• MUSIC for modeling hydrodynamic evolution of the bulk medium
• iSS for modeling hadronization of the bulk medium

These modules are correlated with each other, such that the energy of the hard partons is subtracted from 3DGlauber. Hard scatterings are first sampled at binary collision points provided by the 3D-Glauber. They are then propagated backward in space-time following an initial-state shower to obtain the initiating particle's energies and momenta before the collision. These energies and momenta are then subtracted from the incoming colliding nucleons for the 3D-Glauber + hydrodynamics framework. This new hybrid approach includes non-trivial correlations between jet and soft particle production in small systems.

Except iMatter module, the 3DGlauber, MUSIC and iSS modules should be installed from the external part. To download the latest versions of 3DGlauber, MUSIC and iSS, one can run the shell script under the external_packages folder,

    ./get_3dglauber.sh
    ./get_music.sh
    ./get_iSS.sh

From the build folder, call cmake with the 3DGlauber, MUSIC and iSS flags:

mkdir build
cd build
cmake .. -DUSE_3DGlauber=ON -DUSE_MUSIC=ON -DUSE_ISS=ON
make -j4   # Builds using 4 cores; adapt as appropriate

After using 3DGlauber, iMATTER, MUSIC and iSS support to compile XSCAPE, one can use ./PythiaIsrMUSIC (in the build directory) to iMatter, 3DGlauber, MUSIC and iSS which uses the xml user file config/jetscape_user_iMATTERMCGlauberMUSIC.xml