# Masses of the lowest spin-0 and spin-1 meson nonets: explicit symmetry breaking effects

## TL;DR

This paper extends a multi-quark Lagrangian to include vector and axial-vector interactions, analyzing their effects on the mass spectrum of low-lying meson nonets, aligning with experimental expectations.

## Contribution

It introduces additional multi-quark interactions into the NJL model and examines their impact on meson mass spectra.

## Key findings

- Mass spectrum aligns with phenomenological data
- New interactions significantly influence meson masses
- Model extension improves understanding of symmetry breaking effects

## Abstract

We extend a known multi-quark three-flavor Lagrangian of the Nambu-Jona-Lasinio type, which includes a set of effective interactions proportional to the current quark masses, to include the multi-quark interactions of vector and axial-vector types. It is shown that the mass spectrum of the four low-lying meson nonets are in agreement with current phenomenological expectations. The role of the new interactions is analyzed in detail.