Study of e⁺ e⁻ → h⁺ h⁻ J/ψ (h = π, K, p) via initial-state radiation at Belle II

Using a data sample of 427.9 fb⁻¹ collected by the Belle II detector at or near the ϒð4SÞ and ϒ(10753) resonances, the cross sections for e⁺e⁻ → h⁺h⁻J/ψ(h ¼ π/K/p) at center-of-mass energies ranging from 3.8 GeV or the production threshold to 5.5/6.0/7.0 GeV have been measured via initial-state radiation. The cross sections for the processes e⁺e⁻ → π⁺π⁻J/ψ and e⁺e⁻ → K⁺K⁻J/ψ are consistent with previously published results. The cross sections for these channels obtained by combining with previous Belle results are also given. The process [Formula presented] is investigated for the first time. The yields are small and no significant structure is observed in the cross section versus energy. Searches for vector charmoniumlike states in the h⁺h⁻J/ψ systems, and for associated intermediate states in the h^±/ψ systems, are also presented.