Pseudoscalar charmonium pair interactions via the Pomeron exchange mechanism

Abstract

Following the observation of the fully-heavy tetraquark candidates $X(6900)$ and possible $X(6300)$ in the di-$J/\psi$ spectrum by the LHCb Collaboration, we investigate the near-threshold dynamics of the pseudoscalar quarkonium pairs in a coupled-channel approach in the di-${\eta }_c$ channel. We show that the Pomeron exchange mechanism should be a general dynamics in the near-threshold heavy quarkonium pair interactions. In the di-${\eta }_c$ channel, a coupled-channel system involving the di-${\eta }_c$, ${\eta }_c$-${\eta }_c(2S)$ and di-${\eta }_c(2S)$ interactions can be established. Their $S$-wave interactions near threshold via the Pomeron exchange potential can produce near-threshold resonance poles similar to the di-$J/\psi$, $J/\psi$-$\psi (2S)$ and di-$\psi (2S)$ coupled channels. Interestingly, we find here that the pole positions are more shifted to the corresponding thresholds and turn out to be different from those seen in the di-$J/\psi$ spectrum. Taking into account the suppression of the heavy quark spin flips in the transitions between two vector and two pseudoscalar heavy quarkonium systems, the enhancements in the di-${\eta }_c$ spectrum should be different from those seen in the di-$J/\psi$ channel. Experimental study of the di-${\eta }_c$ channel should be useful for disentangling the nature of the fully-heavy tetraquark systems.

Revtex, 9 pages, 4 figures

References in corpus (13)

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Cited by in corpus (9)

• $S$-wave fully charmed tetraquark resonant states
• Benchmark calculations of fully heavy compact and molecular tetraquark states
• Spectrum of the S-wave fully-heavy tetraquark states
• Going in quest of potential tetraquark interpretations for the newly observed $T_{\psi \psi }$ states in light of the diquark-antidiquark scenarios
• Study of $X(6900)$ with unitarized coupled channel scattering amplitudes
• Nature of the $X(6900)$ in partial wave decomposition of $J/\psi J/\psi$ scattering
• The $X(6900)$ peak could be a molecular state
• Fully charmed P-wave tetraquark resonant states in the quark model
• ${\eta }_c{\eta }_c$ and $J/\psi J/\psi$ scatterings from lattice QCD