Hunting for states in the recent LHCb di-J/ψ invariant mass spectrum

Partial wave analysis is performed, with effective potentials as dynamical inputs, to scrutinize the recent LHCb data on the di-J/psi invariant mass spectrum. Coupled-channel effects are incorporated in the production amplitude via final state interactions. The LHCb data can be well described. A dynamically generated pole structure, which can be identified as the X(6900) state, is found. Our analysis also provides hints for the existence of three other possible states: a bound state X(6200), a broad resonant state X(6680) and a narrow resonant state X(7200). The JPC quantum numbers of the X(6680) and X(6900) states should be 2(++), while the X(6200) and X=(7200) states prefer 0(++). To determine the above states more precisely, more experimental data for the channels, such as J/psi psi(2S), J/psi psi(3770), di-psi(2S), are required.

Automated summary

Partial wave analysis was conducted using effective potentials to scrutinize recent LHCb data on the di-J/psi invariant mass spectrum. Coupled-channel effects were taken into account in the production amplitude via final state interactions. A dynamically generated pole structure identified as the X(6900) state was found, along with hints of three other possible states. More experimental data, such as J/psi psi(2S), J/psi psi(3770), and di-psi(2S), are needed for further determination of these states.