Low-density in-medium effects on light clusters from heavy-ion data

Helena Pais , Rémi Bougault (1) , Francesca Gulminelli (1) , Constança Providência , Eric Bonnet (2) , Bernard Borderie (3) , Abdelouahad Chbihi (4) , John D. Frankland (4) , Emmanuelle Galichet (3, 5) , Diégo Gruyer (1) , Maxime Henri (4) , Nicolas Le Neindre (1) , Olivier Lopez (1) , Loredana Manduci (1, 6) , Marian Parlôg (1) , Giuseppe Verde

1 LPCC - Laboratoire de physique corpusculaire de Caen
2 SUBATECH - Laboratoire de physique subatomique et des technologies associées
3 IPNO - Institut de Physique Nucléaire d'Orsay
4 GANIL - Grand Accélérateur National d'Ions Lourds
5 CNAM - Conservatoire National des Arts et Métiers [CNAM]
6 EAMEA - Ecole des applications militaires de l'énergie atomique

The modification of the ground state properties of light atomic nuclei in the nuclear and stellar medium is addressed, using chemical equilibrium constants evaluated from a new analysis of the intermediate energy heavy-ion (Xe+Sn) collision data measured by the INDRA Collaboration. Three different reactions are considered, mainly differing by the isotopic content of the emission source. The thermodynamic conditions of the data samples are extracted from the measured multiplicities allowing for a parametrization of the in-medium modification, determined with the single hypothesis that the different nuclear species in a given sample correspond to a unique common value for the density of the expanding source. We show that this correction, which was not considered in previous analyses of chemical constants from heavy-ion collisions, is necessary, since the observables of the analyzed systems show strong deviations from the expected results for an ideal gas of free clusters. This dataset is further compared to a relativistic mean-field model, and seen to be reasonably compatible with a universal correction of the attractive σ-meson coupling.

Mots clés: Nuclear Physics

Domaines: Physique Nucléaire Théorique [nucl-th]; Astrophysique [astro-ph]

Helena Pais, Rémi Bougault, Francesca Gulminelli, Constança Providência, Eric Bonnet, et al.. Low-density in-medium effects on light clusters from heavy-ion data. Physical Review Letters, 2020, 125 (1), pp.012701. ⟨10.1103/PhysRevLett.125.012701⟩. ⟨hal-02447884⟩