4D T’- Expansion Scheme (4D-TExS)

The 4D-TExS (Four-Dimensional T′ Expansion Scheme) module of the NSF-funded [MUSES](https://musesframework.io/) project provides a four-dimensional equation of state (EoS) for strongly interacting nuclear matter at finite temperature \(T\), and finite baryon number, electric charge, and strangeness chemical potentials: \(\mu_B\), \(\mu_Q\), and \(\mu_S\), respectively.

This module is based on the T′ Expansion Scheme, which is a resummation of the Taylor expansion of lattice QCD results, extending to higher values of chemical potential than the Taylor expansion available in the BQS module of MUSES. It also relies on a new set of continuum estimated set of second- and fourth-order susceptibilities from lattice QCD calculations at zero chemical potentials.

It can be used to compute a nuclear equation of state for a temperature range of \(30 < T < 500\) MeV, and for chemical potential magnitudes up to approximately \(\mu \sim 700\) MeV depending on the direction in the \((\mu_B, \mu_Q, \mu_S)\) space (with \(\mu^2 = \mu_B^2 + \mu_Q^2 + \mu_S^2\)).

When using results from this module for scientific publication, please cite:
A. Abuali, S. Borsanyi, Z. Fodor, J. Jahan, et. al. , arXiv:2504.01881 [hep-lat]

Original source code was developed by: Johannes Jahan\(^{(1)}\), Paolo Parotto\(^{(2)}\) & Hitansh Shah\(^{(1)}\).
Module development, code adaptation and documentation: Johannes Jahan\(^{(1)}\) & Hitansh Shah\(^{(1)}\).
\(^{(1)}\) Department of Physics, University of Houston, Houston, TX 77204, USA.
\(^{(2)}\) Dipartimento di Fisica, Università di Torino and INFN Torino, Via P. Giuria 1, I-10125 Torino, Italy.