Extended parity doublet model with a new transport code

TL;DR

This paper introduces a new transport code for simulating low-energy heavy-ion collisions and applies an extended parity doublet model to study how chiral invariant mass affects collision dynamics and observable quantities.

Contribution

The paper presents a novel transport code, DJBUU, and applies an extended parity doublet model to explore the impact of chiral invariant mass on collision outcomes.

Findings

Validation of DJBUU through Au+Au collision simulations and box calculations.

Dependence of effective nucleon mass on chiral invariant mass.

Variation of transverse flow with different chiral invariant masses.

Abstract

A new transport code "DaeJeon Boltzmann-Uehling-Uhlenbeck (DJBUU)" had been developed and enables to describe the dynamics of heavy-ion collisions in low-energy region. To confirm the validity of the new code, we first calculate Au + Au collisions at Ebeam = 100 and 400A MeV and also perform the box calculation to check the detail of collisions and Pauli blocking without mean-field potential as suggested by the Transport Code Comparison Project. After confirming the validity of new transport code, we study low-energy heavy-ion collisions with an extended parity doublet model. Since the distinctive feature of the parity doublet model is the existence of the chiral invariant mass that contributes to the nucleon mass, we investigate how physical quantities depend on the chiral invariant mass in heavy ion collisions at low energies. For this, we calculate physical quantities such as the effective nucleon mass in central collisions and transverse flow in semi-central collisions of Au + Au at Ebeam = 400A MeV with different values of the chiral invariant masses.