Searching for beauty-fully bound tetraquarks using lattice nonrelativistic QCD

Abstract

Motivated by multiple phenomenological considerations, we perform the first search for the existence of a bbbb tetraquark bound state with a mass below the lowest noninteracting bottomonium-pair threshold using the first-principles lattice nonrelativistic QCD methodology. We use a full S-wave color/spin basis for the bbbb operators in the three 0++, 1+- and 2++ channels. We employ four gluon field ensembles at multiple lattice spacing values ranging from a=0.06-0.12 fm, all of which include u, d, s and c quarks in the sea, and one ensemble which has physical light-quark masses. Additionally, we perform novel exploratory work with the objective of highlighting any signal of a near threshold tetraquark, if it existed, by adding an auxiliary potential into the QCD interactions. With our results we find no evidence of a QCD bound tetraquark below the lowest noninteracting thresholds in the channels studied.