2023/09/21 by Y. Pan, Ming-Zhu Liu, Pan, Ya-Wen +3
Physics and Astronomy · #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #High-Energy Particle Collisions Research
paper · pdf · doi:10.48550/arxiv.2309.12050
The partial decay widths and production mechanism of the three pentaquark states, PψN(4312), PψN(4440), and PψN(4457), discovered by the LHCb Collaboration in 2019, are still under debate. In this work, we employ the contact-range effective field theory approach to construct the D(*)Σc(*), D*Λc, DΛc, J/ψp, and ηc p coupled-channel interactions to dynamically generate the multiplet of hidde-charm pentaquark molecules by reproducing the masses and widths of PψN(4312), PψN(4440), and PψN(4457). Assuming that the pentaquark molecules are produced in the Λb decay via the triangle diagrams, where Λb firstly decays into Ds(∗)Λc, then Ds(∗) scatters into D(∗)K, and finally the molecules are dynamically generated by the D(∗)Λc interactions, we calculate the branching fractions of the decays Λb → PψNK using the effective Lagrangian approach. With the partial decay widths of these pentaquark molecules, we further estimate the branching fraction of the decays Λb → ( PψN → J/ψp )K and Λb → ( PψN→ D^* Λc )K . Our results show that the pentaquark states PψN(4312), PψN(4440), and PψN(4457) as hadronic molecules can be produced in the Λb decay, and on the other hand their heavy quark spin symmetry partners are invisible in the J/ψp invariant mass distribution because of the small production rates. Our studies show that is possible to observe some of the pentaquark states in the Λb→ D^*Λc K decays.