Exploring the $ \Omega^- $ spectrum in lattice QCD

TL;DR

This lattice QCD study explores the spectrum of the Omega-minus baryon, identifying multiple states and their quantum numbers, and suggests the experimental Omega(2012) resonance comprises overlapping states with different spins.

Contribution

The paper provides the first detailed lattice QCD analysis of the Omega-minus spectrum, assigning quantum numbers to observed states and clarifying the nature of the Omega(2012) resonance.

Findings

Omega(2012) corresponds to two overlapping resonances with different spins.

Identified ground and excited states across a range of light quark masses.

Proposed quantum number assignments for higher energy resonances.

Abstract

We present an exploratory lattice QCD analysis of the $ \Omega $-baryon spectrum. Using smeared three-quark operators in a correlation matrix analysis, we report masses for the ground, first and second excited states of the $ J^P = 1/2^\pm,\, 3/2^\pm $ spectra across a broad range in the light quark mass. We investigate the parity and spin quantum numbers for the states observed on the lattice, looking to reconcile these with the resonances encountered in experiment. We find that the $ \Omega^-(2012) $ as reported by the Particle Data Group corresponds to two overlapping resonances with $ J^P = 1/2^- $ and $ 3/2^- $. We also propose quantum number assignments for the higher energy resonances, and identify successive radial excitations within the spectra.