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 abbbb 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 thebbbb operators in the three 0 þþ , 1 þ− and 2 þþ channels. We employ four gluon field ensembles at multiple lattice spacing values ranging from a ¼ 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.

Heavy-flavored tetraquark states with the QQQ¯Q¯ configuration

“…This observation is consistent with those in Refs. [74,79,82]. The lowest bbbb mass in [79] and ours are similar.…”

“…If the P-wave cccc state exists where the orbital angular momentum contributes some repulsion, the lower ground tetraquark states should also exist. Recently, there are further discussions about the properties of fully-heavy tetraquarks [74][75][76][77][78][79][80][81][82][83][84].…”

Search for beautiful tetraquarks in the ϒ(1S)μ+μ− invariant-mass spectrum

“…[22], and the product of its production cross-section at the LHC and the branching fraction to four muons is estimated to be of O(1 fb). However, recent lattice QCD calculations do not find evidence for such a state in the hadron spectrum [23].…”

Spectrum of the fully-heavy tetraquark state QQQ¯′Q¯Wang1, Meng2, Zhu3 2019Phys. Rev. D11314691View full textAdd to dashboardCite

“…[46] investigated the mass spectra of the QQQQ states in the Chromomagnetic interaction (CMI) model and concluded that no stable QQQQ states exist. Later, several other approaches, such as the nonrelativistic chiral quark model [47,48], the lattice QCD [49] and other models [50,51] also do not support the existence of the bound QQQQ states.…”