A look inside charmed-strange baryons from lattice QCD

TL;DR

This paper computes electromagnetic form factors of various $ ext{Omega}$ baryons using lattice QCD, revealing insights into their charge distributions, magnetic moments, and deformation, especially highlighting the role of charm quarks.

Contribution

It provides the first detailed lattice QCD calculations of electromagnetic properties of spin-3/2 and spin-1/2 $ ext{Omega}$ baryons, including deformation and quark sector contributions.

Findings

Charm quark contributions are smaller than strange-quark contributions.

Electric charge distributions of $ ext{Omega}_{cc}^*$ and $ ext{Omega}_{ccc}$ are oblate.

Results offer insights into heavy-quark dynamics in charmed baryons.

Abstract

The electromagnetic form factors of the spin-3/2 $\Omega$ baryons, namely $\Omega$, $\Omega_c^\ast$, $\Omega_{cc}^\ast$ and $\Omega_{ccc}$, are calculated in full QCD on $32^3\times 64$ PACS-CS lattices with a pion mass of 156(9) MeV. The electric charge radii and magnetic moments from the $E0$ and $M1$ multipole form factors are extracted. Results for the electric quadrupole form factors, $E2$, are also given. Quark sector contributions are computed individually for each observable and then combined to obtain the baryon properties. We find that the charm quark contributions are systematically smaller than the strange-quark contributions in the case of the charge radii and magnetic moments. $E2$ moments of the $\Omega_{cc}^\ast$ and $\Omega_{ccc}$ provide a statistically significant data to conclude that their electric charge distributions are deformed to an oblate shape. Properties of the spin-1/2 $\Omega_c$ and $\Omega_{cc}$ baryons are also computed and a thorough comparison is given. This complete study gives valuable hints about the heavy-quark dynamics in charmed hadrons.