Exotic fully heavy <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>Q</mml:mi><mml:mover accent="true"><mml:mi>Q</mml:mi><mml:mo stretchy="false">¯</mml:mo></mml:mover><mml:mi>Q</mml:mi><mml:mover accent="true"><mml:mi>Q</mml:mi><mml:mo stretchy="false">¯</mml:mo></mml:mover></mml:math> tetraquark states in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mn mathvariant="bold">8</mml:mn><mml:mrow><mml:mo stretchy="false">[</mml:mo><mml:mi>Q</mml:mi><mml:mover accent="true"><mml:mi>Q</mml:mi><mml:mo stretchy="false">¯</mml:mo></mml:mover><mml:mo stretchy="false">]</mml:mo></mml:mrow></mml:msub><mml:mo stretchy="false">⊗</mml:mo><mml:msub><mml:mn mathvariant="bold">8</mml:mn><mml:mrow><mml:mo stretchy="false">[</mml:mo><mml:mi>Q</mml:mi><mml:mover accent="true"><mml:mi>Q</mml:mi><mml:mo stretchy="false">¯</mml:mo></mml:mover><mml:mo stretchy="false">]</mml:mo></mml:mrow></mml:msub></mml:math> color configuration
Qi-Nan Wang, Zi-Yan Yang, Wei Chen
Abstract
We have systematically calculated the mass spectra for S-wave and P-wave fully charm $c\overline{c}c\overline{c}$ and fully bottom $b\overline{b}b\overline{b}$ tetraquark states in the ${\mathbf{8}}_{[Q\overline{Q}]}\ensuremath{\bigotimes}{\mathbf{8}}_{[Q\overline{Q}]}$ color configuration, by using the moment QCD sum rule method. The masses for the fully charm $c\overline{c}c\overline{c}$ tetraquark states are predicted about 6.3--6.5 GeV for S-wave channels and 7.0--7.2 GeV for P-wave channels. These results suggest the possibility that there are some ${\mathbf{8}}_{[c\overline{c}]}\ensuremath{\bigotimes}{\mathbf{8}}_{[c\overline{c}]}$ components in LHCb's di-$J/\ensuremath{\psi}$ structures. For the fully bottom $b\overline{b}b\overline{b}$ system, their masses are calculated around 18.2 GeV for S-wave tetraquark states while 18.4--18.8 GeV for P-wave ones, which are below the ${\ensuremath{\eta}}_{b}{\ensuremath{\eta}}_{b}$ and $\mathrm{\ensuremath{\Upsilon}}(1S)\mathrm{\ensuremath{\Upsilon}}(1S)$ two-meson decay thresholds.