Multiquark interactions and heavy hybrid stars

TL;DR

This paper develops a hybrid equation of state combining NJL and relativistic mean field models to explore the existence of heavy hybrid stars exceeding 2 solar masses, emphasizing the role of multi-quark interactions.

Contribution

It introduces an NJL model with 8-quark interactions and identifies parameter regions supporting massive hybrid stars over 2 solar masses.

Findings

Hybrid stars with >2 solar masses are possible within specific multi-quark coupling parameters.

The model demonstrates the significance of 4-quark and 8-quark vector couplings in stellar mass predictions.

A combined NJL and mean field approach effectively describes dense matter in hybrid stars.

Abstract

We introduce a two flavor Nambu--Jona-Lasinio (NJL) model with 8-quark interactions in the scalar and the vector channel. With the lower density region described by the density-dependent relativistic mean field model we construct a hybrid equation of state. We especially focus on the 4-quark vector couplings and the 8-quark vector NJL couplings and allocate a region in this parameter subspace where hybrid stars with masses larger than $2M_\odot$ exist.