Three hidden-charm pentaquark $P_c$ states, $P_c(4312)$, $P_c(4440)$ and $P_c(4457)$ were revealed in the ${\Lambda }_b^0\to J/\psi p{K}^{-}$ process measured by LHCb using both Run I and Run II data. Their nature is under lively discussion, and their quantum numbers have not been determined. We analyze the $\jp$ invariant mass distributions under the assumption that the crossed-channel effects provide a smooth background. For the first time, such an analysis is performed employing a coupled-channel formalism with the scattering potential involving both one-pion exchange as well as short-range operators constrained by heavy quark spin symmetry. We find that the data can be well described in the hadronic molecular picture, which predicts seven ${\Sigma }_c^{(*)}{\bar{D}}^{(*)}$ molecular states in two spin multiplets, such that the $P_c(4312)$ is mainly a ${\Sigma }_c\bar{D}$ bound state with $J^P=1/2^{-}$, while $P_c(4440)$ and $P_c(4457)$ are ${\Sigma }_c{\bar{D}}^{*}$ bound states with quantum numbers $3/2^{-}$ and $1/2^{-}$, respectively. We also show that there is evidence for a narrow ${\Sigma }_c^{*}\bar{D}$ bound state in the data which we call $P_c(4380)$, different from the broad one reported by LHCb in 2015. With this state included, all predicted ${\Sigma }_c\bar{D}$, ${\Sigma }_c^{*}\bar{D}$, and ${\Sigma }_c{\bar{D}}^{*}$ hadronic molecules are seen in the data, while the missing three ${\Sigma }_c^{*}{\bar{D}}^{*}$ states are expected to be found in future runs of the LHC or in photoproduction experiments.

中文翻译：

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LHCbPc的状态解释为强子分子，并暗示有狭窄的Pc（4380）

三个隐藏的魅力五夸克 $P_C$ 状态， $P_C（4312）$， $P_C（4440）$ 和 $P_C（4457）$ 被揭示在 ${\Lambda }_b^0\to Ĵ/\psi p{ķ}^{-}$LHCb使用运行I和运行II数据测量的过程。它们的性质正在热烈讨论中，其量子数尚未确定。我们假设交叉通道效应提供了平滑的背景，从而分析了$ \ jp $不变质量分布。首次使用耦合通道形式进行这样的分析，其散射势涉及一键交换和受重夸克自旋对称性约束的短距离算子。我们发现该数据可以在强子分子图中很好地描述，它预测了七个${\Sigma }_C^{（*）}{\stackrel{〜}{d}}^{（*）}$ 两个自旋多重态的分子态 $P_C（4312）$ 主要是 ${\Sigma }_C\stackrel{〜}{d}$ 结合状态 ${Ĵ}^P=\mathrm{1个}/2^{-}$，而 $P_C（4440）$ 和 $P_C（4457）$ 是 ${\Sigma }_C{\stackrel{〜}{d}}^{*}$ 量子数的束缚态 $3/2^{-}$ 和 $\mathrm{1个}/2^{-}$， 分别。我们还表明，有证据表明${\Sigma }_C^{*}\stackrel{〜}{d}$ 数据中的绑定状态 $P_C（4380）$，与LHCb在2015年报告的广泛报告不同。 ${\Sigma }_C\stackrel{〜}{d}$， ${\Sigma }_C^{*}\stackrel{〜}{d}$和 ${\Sigma }_C{\stackrel{〜}{d}}^{*}$ 在数据中可以看到强子分子，而缺少的三个 ${\Sigma }_C^{*}{\stackrel{〜}{d}}^{*}$ 有望在大型强子对撞机的未来运行或照相生产实验中找到这些状态。