Exploring possibly existing $q q \bar b \bar b$ tetraquark states with $q q = ud, ss, cc$

TL;DR

This study uses lattice QCD to investigate the potential existence of stable $qq ar b ar b$ tetraquark states, finding evidence for a bound state with specific quantum numbers for the $ud$ case.

Contribution

The paper introduces a lattice QCD approach combined with Schrödinger equation solutions to predict stable tetraquark states with finite-mass quarks.

Findings

Bound state found for $qq=ud$ with $I(J^P)=0(1^+)$

No bound states for $qq=cc$ or $ss$ or $I=1$ cases

Potentially stable tetraquark state identified for specific quark configuration

Abstract

We compute potentials of two static antiquarks in the presence of two quarks $qq$ of finite mass using lattice QCD. In a second step we solve the Schr\"odinger equation, to determine, whether the resulting potentials are sufficiently attractive to host a bound state, which would indicate the existence of a stable $q q \bar b \bar b$ tetraquark. We find a bound state for $qq=(ud-du)/\sqrt{2}$ with corresponding quantum numbers $I(J^ P)=0(1^+)$ and evidence against the existence of bound states with isospin $I=1$ or $qq \in \{cc,ss \}$