Exotic baryons as a hadronic molecule in the heavy quark region

Abstract

Abstract. We study the hadronic molecules formed by the coupled-channel system ofc , inspired by the two hidden-charm pentaquark states observed by LHCb collaborations in 2015. In these molecules, the coupled channels ofD ( * ) Σ ( * ) c are important because the thresholds of these channels are approximately degenerated by the heavy quark spin symmetry. In addition, we consider the coupling to theD ( * ) Λ c channel whose thresholds are close to theD ( * ) Σ ( * ) c thresholds, and the coupling to the state with 0 mixed by the tensor force. By solving the coupled-channel Schrödinger equations with the one meson exchange potentials, we study the hidden-charm hadronic molecules with I(J P ) = 1/2(3/2 ± ) and 1/2(5/2 ± ). We conclude that the J P assignment of the observed pentaquarks is 3/2 + for P + c (4380) and 5/2 − for P + c (4450), which is agreement with the results of the LHCb analysis. In addition, we give predictions for other J P = 3/2 ± states.