Diquark correlations in baryon spectroscopy and holographic QCD

Abstract

We introduce an improved mass formula for the nucleon and delta resonances and show how it emerges from AdS/QCD in a straightforward extension of the 'metric soft wall' gravity dual. The resulting spectrum depends on just one adjustable parameter, characterizing confinement-induced IR deformations of the anti-de Sitter (AdS) metric, and on the fraction of 'good' (i.e. maximally attractive) diquarks in the baryon's quark model wave function. Despite its simplicity, the predicted spectrum describes the masses of all 48 observed light-quark baryon states and their linear trajectory structure with unprecedented accuracy.