Deconfined quark matter in compact stars: equation of state, metastability, and nucleation
by
DrMirco Guerrini(University of Ferrara)
→
Asia/Shanghai
Online Only
Online Only
Description
Abstract:
The behavior of strongly interacting matter at densities above nuclear saturation and the associated deconfinement phase transition remain open problems. Such conditions may arise in compact stars and related phenomena, such as binary mergers and core-collapse supernovae, which are now increasingly accessible through multimessenger astronomy. Phenomenological scenarios for compact stars depend crucially on whether strange quark matter (SQM) is absolutely stable: if not, sufficiently high central densities yield hybrid stars; by contrast, under the Bodmer–Witten hypothesis SQM is the true ground state, and metastable neutron stars (NSs) may coexist with stable strange quark stars (QSs), leading to the two-families scenario.
I will address two complementary aspects of modeling deconfinement. First, a finite-temperature framework for first-order hadron–quark transitions in which charge neutrality is enforced through a continuous interpolation between local and global conservation, recovering the Maxwell and Gibbs constructions as limiting cases and making the mixed-phase strength tunable in a thermodynamically consistent way. Second, the role of metastability and nucleation: a first-order transition can leave the system trapped in a local minimum until a fluctuation overcomes the barrier. This is particularly relevant in the two-families scenario in which hadronic matter is always metastable against conversion to SQM. I study its decay via nucleation, incorporating strong-interaction constraints, thermal composition fluctuations, and color superconductivity, and apply it to proto-neutron stars to assess whether long-lived NS and QS populations can coexist. Finally, I present a first Bayesian analysis of the two-families scenario using current multimessenger data.
