S= −1 meson-baryon interaction in hot and dense nuclear matter: chiral symmetry, many-body and unitarization for a road to GSI/FAIR

Abstract

Abstract. The dynamics of strange pseudoscalar and vector mesons in hot and dense nuclear matter is studied within a chiral unitary framework in coupled channels. Our results set up the starting point for implementations in microscopic transport approaches of heavy-ion collisions, particularly at the conditions of the forthcoming experiments at GSI/FAIR and NICA-Dubna. In theKN sector we focus on the calculation of (off-shell) transition rates for the most relevant binary reactions involved in strangeness production close to threshold energies, with special attention to the excitation of sub-threshold hyperon resonances and isospin effects (e.g.K p vsKn). We also give an overview of recent theoretical developments regarding the dynamics of strange vector mesons (K * ,K * and φ) in the nuclear medium, in connection with experimental activity from heavy-ion collisions and nuclear production reactions. We emphasize the role of hadronic decay modes and the excitation of hyperon resonances as the driving mechanisms modifying the properties of vector mesons.

ϕ meson self-energy in nuclear matter from ϕN resonant interactions

“…The addition of new decay channels in nuclear matter when the KK cloud is modified, such as φN → KY and φN → [KΛ(1405)] → KπY , already induces a substantial broadening of the φ spectral function as compared to the vacuum case, as was already shown in Refs. [29,32,33] 4 , with a considerable population of the low-energy tail (which is further enhanced at high temperatures [52]) and a practically negligible mass shift. When considering, on top of the former, the self-energy generated by the φN interaction, an overall increase of the broadening is observed whereas at the same time some structure appears in the spectral function.…”