Chiral effective theory of scalar and vector diquarks revisited

TL;DR

This paper revisits the chiral effective theory of light diquarks, deriving mass formulas and analyzing their behavior under chiral symmetry restoration, with implications for heavy baryon spectra.

Contribution

It constructs a new effective Lagrangian incorporating chiral and $U(1)_A$ symmetry effects, providing updated mass formulas for various diquark types and their role in heavy baryons.

Findings

Derived mass formulas for scalar, pseudoscalar, vector, and axial-vector diquarks.

Analyzed diquark mass dependence on chiral symmetry breaking and $U(1)_A$ anomaly.

Predicted changes in heavy baryon spectra and decay widths under chiral symmetry restoration.

Abstract

Chiral effective theory of light diquarks is revisited. We construct an effective Lagrangian based on the linear representation of three-flavor chiral symmetry. Here, we focus on the effect of a chiral and $U(1)_A$ symmetric term originated from an eight-point quark interaction. From this model, we obtain the mass formulas of scalar, pseudoscalar, vector, and axial-vector diquarks, which also describe the dependence of diquark masses on the spontaneous chiral symmetry breaking and the $U(1)_A$ anomaly. We regard singly heavy baryons as two-body systems composed of one heavy quark and one diquark and then predict the fate of the mass spectrum and the strong decay widths under chiral symmetry restoration.