Journal article

Publication year: 2022

Journal: Physical Review C

Volume number: 105

Issue number: 3

ISSN: 2469-9985

eISSN: 2469-9993

Open access status: Green

DOI Link: https://doi.org/10.1103/PhysRevC.105.034914

Publisher: American Physical Society

Abstract: 
We include effects of chiral symmetry and its restoration in the kinetic equations for baryon propagation and explore the consequences for eta, pi 0, rho, and dilepton production in heavy-ion collisions at (112)A GeV. Numerical calculations are performed using the Giessen Boltzmann-Uehling-Uhlenbeck (GiBUU) microscopic transport model supplemented by the parity-doublet model for the mean fields of the nucleon and the N*(1535) resonance. In this chiral model, a strong drop of the Dirac mass of the N*(1535) in the high-density stage of a collision leads to a considerable enhancement in the production of this resonance as compared to the standard (nonlinear) Walecka model. As the system expands, the Dirac masses of these abundant soft N*(1535) resonances gradually increase and ultimately cross the N eta decay threshold. As a result, an enhanced low-energy eta production is observed in the calculations with chiral mean fields. Comparing with data from the TAPS experiment on eta and pi 0 production, we find that the chiral model improves the agreement for the mt spectra of eta's at small mt in heavy colliding systems. A similar enhancement is also observed in the soft rho production due to chiral symmetry and its partial restoration. The resulting dilepton yields at low and intermediate invariant masses are slightly enhanced due to these chiral effects, which further improves the agreement between GiBUU transport simulations and data from the HADES experiment for C + C at 1A GeV.

Harvard Citation style: Larionov, A. and von Smekal, L. (2022) Effects of chiral symmetry restoration on meson and dilepton production in relativistic heavy-ion collisions, Physical Review C, 105(3), Article 034914. https://doi.org/10.1103/PhysRevC.105.034914

APA Citation style: Larionov, A., & von Smekal, L. (2022). Effects of chiral symmetry restoration on meson and dilepton production in relativistic heavy-ion collisions. Physical Review C. 105(3), Article 034914. https://doi.org/10.1103/PhysRevC.105.034914