The scalar meson puzzle beyond BCS

TL;DR

This paper explores the scalar meson puzzle beyond BCS by analyzing chiral symmetry breaking, coupled channels, and lattice QCD inspired interactions, revealing insights into meson spectrum shifts and decay widths.

Contribution

It introduces a new perspective on the scalar meson puzzle beyond BCS, showing coupled channels reduce chiral symmetry breaking and identifying the f0(980) as the ground state meson.

Findings

Coupled channels reduce chiral symmetry breaking effects.

The f0(980) is identified as the ground state I=0, 3P0 meson.

Chiral condensate is reduced by 30% due to coupled channels.

Abstract

Les We present a new perspective on the scalar meson puzzle from spontaneous breaking of chiral symmetry beyond BCS. We find that going beyond BCS does not produce a systematic shift of the hadron spectrum. We also show that coupled channels reduce the breaking of chiral symmetry, with the same Feynman diagrams that appear in the coupling of a scalar meson to a pair of pseudoscalar mesons. With a Lattice QCD inspired quark-quark interaction, we find that the groundstate I=0, 3P0 quark antiquark meson is the f0(980) with a partial decay width of 40MeV. We also find a 30% reduction of the chiral condensate due to coupled channels.