Antistatic-antistatic $\bar Q \bar Q qq$ potentials for $u$, $d$ and $s$ light quarks from lattice QCD

TL;DR

This paper presents lattice QCD calculations of antistatic-antistatic potentials with two light quarks, exploring various quantum states and improving previous methods, hinting at one-pion exchange effects at larger separations.

Contribution

The study advances lattice QCD computations of $ar Q ar Q qq$ potentials by including more off-axis separations and applying tree-level improvements, providing new insights into light quark interactions.

Findings

Potential indicates possible one-pion exchange at separations > 0.5 fm.

Use of 16 creation operators across multiple quantum sectors.

Enhanced accuracy over previous lattice QCD studies.

Abstract

We report on our ongoing lattice QCD computation of antistatic-antistatic potentials in the presence of two light quarks using the CLS $N_f=2$ gauge configurations and the OpenQ*D codebase. We utilize a set of 16 creation operators, corresponding to 8 sectors characterized by angular momentum and parity quantum numbers for light quarks $qq = (ud - du) / \sqrt{2}$ (isospin $0$), $qq \in \{ uu , (ud + du) / \sqrt{2}, dd \}$ (isospin $1$) and $qq \in \{ us , ds \}$ (isospin $1/2$ and strangeness $-1$). We improve on previous work by considering a large number of off-axis separations of the static antiquarks and by using tree-level improvement. The resulting potentials provide vague indication for one-pion exchange at $\bar Q \bar Q$ separations $r \gtrapprox$ 0.5 fm.