Description

This repository contains the source code for calculations presented in the paper https://arxiv.org/abs/1807.02079

Calculations are performed within the Thermal-FIST package which is used in this repository as a submodule. Therefore, it is advisable to use the --recurse-submodules option when cloning this repository in order to also clone the Thermal-FIST submodule automatically

There are two C++ scripts in the repository, located in the src folder:

• 1807.02079.TDep.cpp - calculates the temperature dependence of the modified hadron yields. This corresponds to the contents of Sec. III of the paper.
• 1807.02079.Fits.cpp - performs thermal fits to ALICE data at different centralities (Sec. IV of the paper).

Both scripts are annotated and can be generalized for other applications.

Usage

The preferred way is to use cmake.

On a Unix-like system one can run the following commands from the root project folder to build the programs:

mkdir build
cd build
cmake ../
make 1807.02079.TDep
make 1807.02079.Fits

This will build the aforementioned 1807.02079.TDep and 1807.02079.Fits executables in the build folder. The dependent Thermal-FIST library will also be built.

Temperature dependence

Running

./1807.02079.TDep

will generate two output files:

• ZeroWidth-vs-BW-vs-eBW-vs-T.dat - contains the temperature dependence of the ratios of various hadron yields calculated in the BW or eBW scheme over the yields calculated in the zero-width approximation. The generated data are plotted in Figs. 1 and 2a of the paper.
• Widths-p-to-pi-vs-T.dat - temperature dependence of the proton-to-pion ratio calculated in the three schemes considered for modeling resonance widths. This is plotted in Fig. 2b of the paper.

The figures below depict the calculation results.

Fig. 1	Fig. 2b

Thermal fits

Running

./1807.02079.Fits

will perform the thermal fits within the three considered schemes to the hadron yield data of the ALICE collaboration at different centralities. The program will output *.txt and *.out files for each fit containing, respectively, the fit log and the resulting data-to-model comparison of hadron yields. These fit results are shown in Figs. 3 and 4, and in Table II of the paper. The fitted data are located in the input/data folder.

Alternatively, one can perform the fits within the QtThermalFIST gui program included in the Thermal-FIST submodule. See more details here.

Attribution

The code here implements calculations from the following paper:

• V. Vovchenko, M.I. Gorenstein, H. Stoecker, Finite resonance widths influence the thermal-model description of hadron yields, Phys. Rev. C 98, 034906 (2018), arXiv:1807.02079 [nucl-th].

Please include a reference to this paper when using this code or its derived version.

Copyright (C) 2018 Volodymyr Vovchenko