Properties of Scalar-Quark Systems in SU(3)c Lattice QCD

TL;DR

This study uses lattice QCD to explore bound states of scalar quarks and their interactions with quarks, revealing that all colored particles tend to gain large effective masses from gluon interactions.

Contribution

First lattice QCD investigation of scalar-quark bound states and their mass generation, highlighting the universal large mass acquired by colored particles due to gluon dressing.

Findings

Scalar-quark hadrons have masses of several GeV.

Bound states involving scalar quarks show similar mass dependence.

All colored particles tend to acquire large effective masses from gluon interactions.

Abstract

We perform the first study for the bound states of colored scalar particles $\phi$ ("scalar quarks") in terms of mass generation with quenched SU(3)$_c$ lattice QCD. We investigate the bound states of $\phi$, $\phi^\dagger\phi$ and $\phi\phi\phi$ ("scalar-quark hadrons"), as well as the bound states of $\phi$ and quarks $\psi$, i.e., $\phi^\dagger\psi$, $\psi\psi\phi$ and $\phi\phi\psi$ ("chimera hadrons"). All these new-type hadrons including $\phi$ have a large mass of several GeV due to large quantum corrections by gluons, even for zero bare scalar-quark mass $m_\phi=0$ at $a^{-1}\sim 1{\rm GeV}$. We find a similar $m_\psi$-dependence between $\phi^\dagger\psi$ and $\phi\phi\psi$, which indicates their similar structure due to the large mass of $\phi$. From this study, we conjecture that all colored particles generally acquire a large effective mass due to dressed gluons.