اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدStrong decays of the $P_{cs}(4459)$ as a $Xi_cbar{D}^{*}$ molecule
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In this work, we study the strong decay of the newly observed $P_{cs}(4459)$ assuming that it is a pure $Xi_cbar{D}^{*}$ molecular state. Considering two possible spin-parity assignments $J^P=1/2^{-}$ and $J^P=3/2^{-}$ the partial decay widths of the $Xi_cbar{D}^{*}$ molecular state into $J/psi{}Lambda$, $D_s^{-}Lambda_c^{+}$, and $DXi_c^{()}$ final states through hadronic loops are evaluated with the help of the effective Lagrangians. In comparison with the LHCb data, the spin-party $J^P=1/2^{-}$ the assignment is preferred while this of $J^P=3/2^{-}$ is disfavored. The $P_{cs}(4459)$ in spin-parity $J^P=3/2^{-}$ case maybe explained as $S$-wave coupled bound state with lager $Xi_cbar{D}^{*}$ component. In addition, the calculated partial decay widths with $J^P=1/2^{-}$ $Xi_cbar{D}^{*}$ molecular state picture indicates that allowed decay mode, $DXi_c^{}$, may have the biggest branching ratio. The experimental measurements for this strong decay process could be a crucial test for the molecule interpretation of the $P_{cs}(4459)$.
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Recently, the LHCb Collaboration reported a new structure $P_{cs}(4459)$ with a mass of 19 MeV below the $Xi_c bar{D}^{*} $ threshold. It may be a candidate of molecular state from the $Xi_c bar{D}^{*} $ interaction. In the current work, we perform a
coupled-channel study of the $Xi_c^*bar{D}^*$, $Xi_cbar{D}^*$, $Xi^*_cbar{D}$, $Xi_cbar{D}^*$, $Xi_cbar{D}$, and $Xi_cbar{D}$ interactions in the quasipotential Bethe-Salpeter equation approach. With the help of the heavy quark chiral effective Lagrangian, the potential is constructed by light meson exchanges. Two $Xi_c bar{D}^{*} $ molecular states are produced with spin parities $ J^P=1/2^-$ and $3/2^- $. The lower state with $3/2^-$ can be related to the observed $P_{cs}(4450)$ while two-peak structure can not be excluded. Within the same model, other strange hidden-charm pentaquarks are also predicted. Two states with spin parities $1/2^-$ and $3/2^-$ are predicted near the $Xi_cbar{D}$, $Xi_cbar{D}$, and $Xi_c^*bar{D}$ thresholds, respectively. As two states near $Xi_c bar{D}^{*}$ threshold, two states are produced with $1/2^-$ and $3/2^-$ near the $Xi_cbar{D}^*$ threshold. The couplings of the molecular states to the considered channels are also discussed. The experimental research of those states are helpful to understand the origin and internal structure of the $P_{cs}$ and $P_c$ states.
Recently, the LHCb Collaboration reported on the evidence for a hidden charm pentaquark state with strangeness, i.e., $P_{cs}(4459)$, in the $J/psiLambda$ invariant mass distribution of the $Xi_b^-to J/psi Lambda K^-$ decay. In this work, assuming th
at $P_{cs}(4459)$ is a $bar{D}^*Xi_c$ molecular state, we study this decay via triangle diagrams $Xi_brightarrow bar{D}_s^{(*)}Xi_cto (bar{D}^{(*)}bar{K})Xi_cto P_{cs} bar{K}to (J/psiLambda) bar{K}$. Our study shows that the production yield of a spin 3/2 $bar{D}^*Xi_c$ state is approximately one order of magnitude larger than that of a spin $1/2$ state due to the interference of $bar{D}_sXi_c$ and $bar{D}_s^*Xi_c$ intermediate states. We obtain a model independent constraint on the product of couplings $g_{P_{cs}bar{D}^*Xi_c}$ and $g_{P_{cs}J/psiLambda}$. With the predictions of two particular molecular models as inputs, we calculate the branching ratio of $Xi_b^-to (P_{cs}to)J/psiLambda K^- $ and compare it with the experimental measurement. We further predict the lineshape of this decay which could be useful to future experimental studies.
Inspired by the observation of the $P_{cs} (4459)$ state by LHCb recently, we reexamine the results of the interaction of the $J/psi Lambda$ channel with its coupled channels, exploiting the coupled channel unitary approach combined with heavy quark
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