Exploring the Di-$J/psi$ Resonances around 6.9 $mathrm{GeV}$ Based on {it{ab initio}} Perturbative QCD


Abstract in English

We propose an {it{ab initio}} method to explore the nature of the newly discovered particle $X$(6900). We find that there should exist another state near the resonance at around 6.9 $mathrm{GeV}$, and the ratio of production cross sections of $X$(6900) to the undiscovered state is very sensitive to the nature of $X$(6900), whereas is almost independent of the transverse momentum and rapidity. This behavior is unlikely changed by higher order corrections. Therefore, the nature of $X$(6900) can be uncovered by experimental facts in the near future. If there is another state near $X$(6900) with cross section larger than half of that of $X$(6900), $X$(6900) should be a tetraquark state. Otherwise, it should be a molecule-like state.

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