2019/06/07 by Xiao-Yun Wang, Jun He, Xu-Rong Chen +2
Physics and Astronomy · #hep-ex #hep-ph #nucl-ex
paper · pdf · doi:10.1016/j.physletb.2019.134862
published as Phys.Lett. B797 (2019) 134862 · 6 pages, 4 figures. arXiv admin note: text overlap with arXiv:1904.11706
arxiv created 2019/06/07 · arxiv updated 2019/09/17
The production of the hidden-charm pentaquarks Pc via pion-induced reaction on a proton target is investigated within an effective Lagrangian approach. Three experimentally observed states, Pc(4312), Pc(4440), and Pc(4457), are considered in the calculation, and the Reggeized t-channel meson exchange is considered as main background for the reaction π-p→ J/ψn. The numerical results show that the experimental data of the total cross section of the reaction π-p→ J/ψn at W≃ 5 GeV can be well explained by contribution of the Reggeized t channel with reasonable cutoff. If the branching ratios Br[Pc→ J/ψN]≃ 3% and Br[Pc→ πN]≃ 0.05% are taken, the average value of the cross section from the Pc(4312) contribution is about 1.2 nb/100 MeV, which is consistent with existing rude data at near-threshold energies. The results indicate that the branching ratios of the Pc states to the J/ψN and πN should be small. The shape of differential cross sections shows that the Reggeized t-channel provides a sharp increase at extreme forward angles, while the differential cross sections from the Pc states contributions are relatively flat. High-precision experimental measurements on the reaction π-p→ J/ψn at near-threshold energies are suggested to confirm the LHCb hidden-charm pentaquarks as genuine states, and such experiments are also helpful to understand the origin of these resonance structures.