Systematics of fully heavy tetraquarks

Abstract

In this work, we systematically study the mass spectrum of the fully-heavy tetraquark in an extended chromomagnetic model, which includes both color and chromomagnetic interactions. Numerical results indicate that the energy level is mainly determined by the color interaction, which favors the color-sextetThe chromomagnetic interaction mixes the two color configurations and gives small splitting. The ground state is always dominated by the color-sextet configuration. We find no stable state below the lowest heavy quarkonium pair thresholds. Most states may be wide since they have at least one S-wave decay channel into two S-wave mesons. One possible narrow state is the 1 + bb bc state with a mass 15719.1 MeV. It is just above the η b Bc threshold. But this channel is forbidden because of the conservation of the angular momentum and parity.

The lineshape of the compact fully heavy tetraquark

“…Among them, our method is similar to that in Ref. [27] and our results should be consistent with each other. However, one can see a deviation from Fig.…”

“…As discussed in the above section, most of the bare fully heavy tetraquarks are above their lowest allowed hidden charm/bottom decay channels [16][17][18][19][20][21][22][23][24][25][26][27][28][29][43][44][45][46][47]. As the result, we will discuss their partial widths of hidden charm/bottom channels.…”

“…For the full-charm tetraquark system cccc, the spectra has been obtained with parameterization scheme in Refs. [27,28,44] and our work, Gaussion expansion method (GEM) [55] in Refs [16,26,29,53] and QCD sum rules in Refs. [47,54].…”

“…For Refs. [27,56] both the light meson and heavy meson masses are used to extract the parameters, which is the reason for the deviation. The spectra can also be obtained by solving Schrödinger equation numerically with the variational method [16,26,29,53], which can only give the upper limits of the system.…”

“…The observation of the X(6900) [12] breaks through the situation. Because of the equal masses of the components, the hadron with cccc quarks is more expected to be a compact one [16][17][18][19][20][21][22][23][24][25][26][27][28][29]. However, none of them fit the di-J/ψ line shape within this scenario, analogous to that within the molecular picture [30][31][32][33].…”