Higher mass spectra of the fully-charmed and fully-bottom tetraquarks

In this work, we calculate the higher mass spectra for the 2S-and 1D-wave fully-charmed and fully-bottom tetraquark states in a nonrelativistic potential quark model. The 2S-wave fully-charmed/bottom tetraquark states lie in the mass range of similar to(6.9, 7.1)/(19.7, 19.9) GeV, apart from the highest 0(++) state T(cc (c) over bar(c) over bar )0++(7185)/T(cc (c) over bar(c) over bar )0++(19976). Most of the 2S-wave states highly overlap with the high-lying 1P wave states. The masses for the 1D-wave fully-charmed/bottom tetraquark states are predicted to be in the range of similar to(6.7, 7.2)/(19.5, 20.0) GeV. The mass range for the D-wave tetraquark states cover most of the mass range of the P-wave states and the whole mass range of the 2S-wave states. The narrow structure X(6900) recently observed at LHCb in the di-J/psi invariant mass spectrum may be caused by the 1P-, or 2S-, or 1D-wave T-(cc (c) over bar(c) over bar) states. The vague structure X(7200) may be caused by the highest 2S-wave state T(cc (c) over bar(c) over bar )0++(7185), two low-lying 3S-wave states T(cc (c) over bar(c) over bar )0++(7240) and T(cc (c) over bar(c) over bar )2++(7248), and/or the high-lying 1D-wave states with masses around 7.2 GeV and JPC = 0(++), 1(++), 2(++), 3(++), or 4(++). While it is apparent that the potential quark model calculations predict more states than the structures observed in the di-J/psi invariant mass spectrum, our calculations will help further understanding of the properties of these fully-heavy tetraquark states in their strong and magnetic interactions with open channels based on explicit quark model wave functions.

Automated summary

In this study, the higher mass spectra for fully-charmed and fully-bottom tetraquark states in 2S and 1D waves were calculated using a nonrelativistic potential quark model. The calculation predicts mass ranges for these states and potential causes for observed structures in experimental data, contributing to the understanding of their properties in strong and magnetic interactions. The potential quark model calculations show more states than observed in experiments, suggesting further research is needed for a comprehensive understanding.