Description of the newly observed Xi _c^{0} states as molecular states

Abstract

Very recently, three new structures Xi _c(2923)^0, Xi _c(2938)^0, and Xi _c(2964)^0 at the invariant mass spectrum of Lambda _c^{+}K^{-} observed by the LHCb Collaboration trigger a hot discussion about their inner structure. In this work, we study the strong decay mode of the newly observed Xi ^0_c assuming that the Xi ^0_c is a bar{D}Lambda -bar{D}Sigma molecular state. With the possible quantum numbers J^p=1/2^{pm } and 3/2^{pm }, the partial decay widths of the bar{D}Lambda -bar{D}Sigma molecular state into the Lambda _c^{+}K^{-}, Sigma _c^{+}K^{-},and Xi _c^{+}pi ^{-} final states through hadronic loop are calculated with the help of the effective Lagrangians. By comparison with the LHCb observation, the current results of total decay width support the Xi _c(2923)^0 as bar{D}Lambda -bar{D}Sigma molecule while the decay width of the Xi _c(2938)^0 and Xi _c(2964)^0 can not be well reproduced in the molecular state picture. In addition, the calculated partial decay widths with S wave bar{D}Lambda -bar{D}Sigma molecular state picture indicate that allowed decay mode, Xi _c^{+}pi ^{-}, may have the biggest branching ratio for the Xi _c(2923)^0. The experimental measurements for this strong decay process could be a crucial test for the molecule interpretation of the Xi _c(2923)^0.