Heavy-heavy-light quark potential in SU(3) lattice QCD

TL;DR

This study explores the potential energy between two heavy quarks and a light quark in SU(3) lattice QCD, revealing a Coulomb plus linear form with reduced string tension due to light-quark effects.

Contribution

First lattice QCD calculation of the heavy-heavy-light quark potential, showing the impact of light quarks on the inter-quark potential and string tension.

Findings

The QQq potential fits a Coulomb plus linear form.

The effective string tension is reduced by light-quark effects.

Light-quark mass influences the potential and string tension.

Abstract

We perform the first study for the heavy-heavy-light quark (QQq) potential in SU(3) lattice QCD. The calculations are done with the standard gauge and $O(a)$-improved Wilson fermion action on the $16^4$ lattice at $\beta =6.0$ at the quenched level. We calculate the energy of QQq systems as the function of the distance between the two heavy quarks, and find that the QQq potential is well described with a Coulomb plus linear potential form. Compared to the static three-quark case, the Coulomb term does not change but the effective string tension between the heavy quarks is significantly reduced by the light-quark effect. We also investigate the light-quark mass dependence of the QQq potential using the four hopping parameters, $\kappa =0.1200,0.1300,0.1340$, and 0.1380. The reduction of the effective string tension is considered to be a general property for baryons and multi-quark hadrons.