Coexistence of Multiple Phases in Magnetized Quark Matter with Vector Repulsion

TL;DR

This paper investigates the complex phase structure of magnetized quark matter with vector interactions, revealing novel triple points and a first-order transition with a negative slope in the phase diagram, relevant for magnetar studies.

Contribution

It uncovers the coexistence of multiple phases and the emergence of two triple points in magnetized quark matter with vector repulsion, a novel phenomenon not previously observed.

Findings

Identification of three-phase coexistence at specific G_V and B values.

Discovery of a first-order transition with negative P-T slope.

Observation of phase diagram features relevant to magnetar conditions.

Abstract

We explore the phase structure of dense magnetized quark matter when a repulsive vector interaction, parametrized by $G_V$, is present. Our results show that for a given magnetic field intensity ($B$) one may find a value of $G_V$ for which quark matter may coexist at three different baryonic density values leading to the appearance of two triple points in the phase diagram which have not been observed before. Another novel result is that at high pressure and low temperature we observe a first order transition which presents a negative slope in the $P-T$ that is reminiscent of the solid-liquid transition line observed within the water phase diagram. These unusual patterns occur for $G_V$ and $B$ values which lie within the range presently considered in many investigations related to the study of magnetars.