Static-light Q̄ Q̄qq potentials for b̄ and c̄ heavy quarks and u, d and s light quarks from lattice QCD. A case study for hadron-hadron interactions

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)/ 2 (isospin 0), 𝑞𝑞 ∈ {𝑢𝑢, (𝑢𝑑 + 𝑑𝑢)/ 2, 𝑑𝑑} (isospin 1) and 𝑞𝑞∈{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 𝑄¯ 𝑄¯ separations 𝑟 >∼ 0.5 fm.

The short stop-motion film “Tetraquarks on the Lattice” by Bernardo Picão will also be presented.