Hunting for exotic doubly hidden-charm/bottom tetraquark states

Abstract

We develop a moment QCD sum rule method augmented by fundamental inequalities to study the existence of exotic doubly hidden-charm/bottom tetraquark states made of four heavy quarks. Using the compact diquark-antidiquark configuration, we calculate the mass spectra of these tetraquark states. There are 18 hidden-charm cccc tetraquark currents with J PC = 0 ++ , 0 −+ , 0 −− , 1 ++ , 1 +− , 1 −+ , 1 −− , and 2 ++ . We use them to perform QCD sum rule analyses, and the obtained masses are all higher than the spontaneous dissociation thresholds of two charmonium mesons, which are thus their dominant decay modes. The masses of the corresponding hidden-bottom bbbb tetraquarks are all below or very close to the thresholds of the Υ(1S )Υ(1S ) and η b (1S )η b (1S ), except one current of J PC = 0 ++ . Hence, we suggest to search for the doubly hidden-charm states in the J/ψJ/ψ and η c (1S )η c (1S ) channels.

Spectrum of the fully-heavy tetraquark state QQQ¯′Q¯Wang1, Meng2, Zhu3 2019Phys. Rev. DSelf Cite10714691View full textAdd to dashboardCite

“…In Table XI, we summarize our numerical results and those from the CMI model [42,43,46], a nonrelativistic effective field theory (NREFT) and a relativized diquark and antidiquark model [33], a diffusion Monte-Carlo method [32], a constituent quark model with the hyperspherical formalism [40], the nonrelativistic potential model [48], and the QCD sum rule [36,56]. In this table, we notice that the numerical results in the two nonrelativistic quark models are similar to each other.…”

Spectroscopy and decays of the fully-heavy tetraquarks

“…If it does, what are their masses and decay properties? Recently, this debate has given rise to several studies within different approaches, including the constituent quark and diquark models [45][46][47][48], chiral quark model [49], chromo-electric potential model [50], and QCD sum rules [51,52]. All of these predict the existence of fullyheavy (bottom) tetraquarks, except for Ref.…”

QQQ¯Q¯ states: Masses, production, and decays

“…(See, for example, Refs. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19].) We will present our own mass estimates, noting experimental strategies that might be particularly appropriate for present-day and near-future searches.…”