Nuclear and Quark Matter Seminar 2021
20 January 2021, 13:30 - online only
Ignazio Bombaci - University of Pisa and INFN, Pisa, Italy
The hyperon puzzle in neutron stars
The so called hyperon puzzle in neutron stars, the difficulty to reconcile the measured masses of neutron stars with the presence of hyperons in their interiors, is one of the hot topics in astrophysics which is stimulating copious experimental and theoretical research in hypernuclear physics and dense matter physics. After illustrating the origin of the hyperon puzzle, I will discuss some of its possible solutions, and particularly those related to the role of hyperonic two- and three-body interactions on the equation of state of dense matter. Afterward, I will discuss a possibility to circumvent the hyperon puzzle allowing for the presence of strangeness in neutron stars in the form of deconfined strange quark matter, and thus considering the so called quark stars, i.e. hybrid stars or strange stars. Finally I will discuss the astrophysical consequences of the possible conversion process of an hadronic star to a quark star.
21 April 2021, 13:30 - online only
Marina Kozhevnikova - JINR, Dubna, Russia
Update of the Three-fluid Hydrodynamics-based Event Simulator (THESEUS) and light-nuclei production in heavy-ion collisions
We present an updated event generator THESEUS, based on the three-fluid dynamics (3FD), complemented by UrQMD cascade for the late stage of the nuclear collision. The generator is extended to simulate light-nuclei production in relativistic heavy-ion collisions via thermal mechanism, on the same basis as hadrons. We present the rapidity, transverse momentum spectra, first v1 flow harmonics of deuterons, tritons, He at different collision energies and impact parameters. The results are compared with experimental data from NA49 and STAR. We show that anti-deuteron spectra from THESEUS are in agreement with STAR data. We demonstrate the contributions from the excited states of Helium to the yields of deuteron, triton and He. The reproduction is achieved without any extra parameters, while the original coalescence approach in 3FD requires a tuning of the coalescence coefficients for each light nucleus separately.
GSI Imprint (in German)
R. Averbeck, V. Friese, B. Friman, R. Holzmann
Last modified: Wed Dec 20 15:13:27 CEST 2017