Triply charmed baryons mass decomposition from lattice QCD

TL;DR

This study uses lattice QCD to decompose the mass of triply charmed baryons, revealing the significant role of charm quarks and the main source of mass splitting between different baryon states.

Contribution

First lattice QCD calculation of charm quark scalar matrix element and momentum fraction in triply charmed baryons, including mass decomposition and comparison with quark model.

Findings

Connected charm quark contributes about 70% of baryon mass.

Charm quark matrix element is about 1.5 times that of charmonium.

Mass splitting mainly from energy-momentum tensor component.

Abstract

We present the first calculation of the connected scalar matrix element and the momentum fraction of charm quark within the$\frac{3}{2}^{+}$ and $\frac{3}{2}^{-}$triply charmed baryons on lattice QCD. The results are based on overlap valence fermions on two ensembles of $N_f=2+1$ domain wall fermion configurations with two lattice spacings. The corresponding sea quark pion masses are $300$ MeV and $278$ MeV. The separated contributions to the triply charmed baryon mass are derived through the decomposition of the QCD energy-momentum tensor. The contribution of the connected charm quark matrix element to the triply charmed baryon is about 3/2 times that of the charmonium. And it contributes almost 70% of the total mass. The mass splitting of $\frac{3}{2}^{+}$ and $\frac{3}{2}^{-}$triply charmed baryons is mainly from $\langle H_{E}\rangle$ of the QCD energy-momentum tensor. A mass decomposition from the quark model is also studied for comparison.