Strangelets at finite temperature: nucleon emission rates, interface and shell effects

Abstract

We investigate the properties of strangelets at finite temperature $T$, where an equivparticle model is adopted with both the linear confinement and leading-order perturbative interactions accounted for using density-dependent quark masses. The shell effects are examined by solving the Dirac equations for quarks in the mean-field approximation, which diminish with temperature as the occupation probability of each single-particle levels fixed by the Fermi-Dirac statistics, i.e., shell dampening. Consequently, instead of decreasing with temperature, the surface tension extracted from a liquid-drop formula increases with $T$ until reaching its peak at $T\approx 20$-40 MeV with vanishing shell corrections, where the formula roughly reproduces the free energy per baryon of all strangelets. The curvature term, nevertheless, decreases with $T$ despite the presence of shell effects. The neutron and proton emission rates are fixed microscopically according to the external nucleon gas densities that are in equilibrium with strangelets, which generally increase with $T$ ($\lesssim 50$ MeV) for stable strangelets but decrease for those that are unstable against nucleon emission at $T=0$. The energy, free energy, entropy, charge-to-mass ratio, strangeness per baryon, and root-mean-square radius of $\beta$-stable strangelets obtained with various parameter sets are presented as well. The results indicated in this work are useful for understanding the products of binary compact star mergers and heavy-ion collisions.

References in corpus (15)

• The Strange Star Surface: A Crust with Nuggets
• Mass Ejection by Strange Star Mergers and Observational Implications
• Thermodynamics with density and temperature dependent particle masses and properties of bulk strange quark matter and strangelets
• The Stability of Strange Star Crusts and Strangelets
• Thermodynamic consistency, quark mass scaling, and properties of strange matter
• Strangelet propagation and cosmic ray flux
• Phase diagram and surface tension in the three-flavor Polyakov-quark-meson model
• Strangelets: Who is Looking, and How?
• Surface effects in color superconducting strange-quark matter
• Charge, strangeness and radius of strangelets
• Non-strange quark stars within resummed QCD
• Interface effects of quark matter: Light-quark nuggets and compact stars
• Rescaling strange-cluster stars and its implications on gravitational-wave echoes
• Structure formation during phase transitions in strongly interacting matter
• Microscopic description of neutron emission rates in compound nuclei

Cited by in corpus (3)

• Strange quark stars: the role of excluded volume effects
• Scaling and universality in strange quark stars
• Compact dwarfs made of light-quark nuggets