Constraining the nuclear symmetry energy with Fermi-energy heavy ion collisions
Year: 2025
Type: article
Abstract: Heavy ion reactions provide a unique opportunity to unveil the Equation of State (EoS) of baryonic matter in a large density domain. However, to get quantitative constraints it is crucial to employ observables that are as insensitive as possible to final state interaction, and at the same time robustly predicted by transport models with limited model dependence. In this work, we compare for the first time BUU transport calculations to the impact parameter dependence of the isospin transport ratio deduced from INDRA-FAZIA data [1], with a model independent evaluation of the impact parameter. Using different state-of-the-art nuclear functionals, provided both by fits of ab initio calculations and by phenomenological approaches, a confidence region for the symmetry energy is extracted. A consistent study of the time dependence of the baryonic density and of the isospin current density allows a precise determination of the density region significantly probed by the experiment, with the definition of confidence regions in the symmetry energy vs density plane. A symmetry energy S = ( 29.0 ± 0.7 ) MeV is obtained for the most significant density ρ / ρ 0 = 1.01 . The obtained symmetry energy constraint can be used to inform Bayesian inference of the neutron star EoS.
Source: Physics Letters B
Authors: C. Ciampi, S. Mallik, F. Gulminelli, D. Gruyer, J.D. Frankland, N. Le Neindre, R. Bougault, A. Chbihi, L. Baldesi, S. Barlini, B. Borderie, A. Camaiani, G. Casini, I. Dekhissi, J.A. Dueñas, Q. Fable, F. Gramegna, M. Henri, B. Hong, S. Kim, A. Kordyasz, T. Kozik, I. Lombardo, O. Lopez, T. Marchi, S.H. Nam, J. Park, M. Pârlog, G. Pasquali, S. Piantelli, G. Poggi, S. Valdré, G. Verde, E. Vient
Institutions: Centre National de la Recherche Scientifique, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Institut National de Physique Nucléaire et de Physique des Particules, Grand Accélérateur National d'Ions Lourds, Variable Energy Cyclotron Centre, Homi Bhabha National Institute, École Nationale Supérieure d'Ingénieurs de Caen, Laboratoire de Physique Corpusculaire de Caen, Université de Caen Normandie, Istituto Nazionale di Fisica Nucleare, Sezione di Firenze, University of Florence, Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie, Universidad de Huelva, Istituto Nazionale di Fisica Nucleare, Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Institut national des sciences et techniques nucléaires, Korea University, Institute for Basic Science
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: diamond
Awards: G1883778784, G227586730
OpenAlex ID: W4413232996