The $X_0(2900)$ observed by the LHCb Collaboration recently in the $D^-K^+$ invariant mass of the $B^+\to D^+D^-K^+$ process is the first exotic candidate with four different flavors, which opens a new era for the hadron community, especially for revealing the mystery of the $D_{s0}(2317)$ and the $D_{s1}(2460)$. We have demonstrated that the $X_0(2900)$ can be well accepted as a $I(J^P)=0(0^+)$ $\bar{D}^*K^*$ hadronic molecule. Its observation could also give the whole heavy-quark symmetry multiplet formed by the $\left(\bar{D},\bar{D}^*\right)$ doublet and the $K^*$ meson. Besides the $X_0(2900)$, there would be two additional $I(J^P)=0(1^+)$ hadronic molecules associated with the $\bar{D}K^*$ and $\bar{D}^*K^*$ channels as well as one additional $I(J^P)=0(2^+)$ $\bar{D}^*K^*$ molecule. In the light quark limit, they are $36.66~\mathrm{MeV}$ and $34.22~\mathrm{MeV}$ below the $\bar{D}K^*$ and $\bar{D}^*K^*$ thresholds, respectively, which are unambiguously fixed by the mass position of the $X_0(2900)$.

中文翻译：

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分子图中的 $X_0(2900)$ 及其重夸克自旋伙伴

LHCb Collaboration 最近在 $B^+\to D^+D^-K^+$ 过程的 $D^-K^+$ 不变质量中观察到的 $X_0(2900)$ 是第一个具有四种不同的口味，开启了强子界的新纪元，特别是揭开了$D_{s0}(2317)$和$D_{s1}(2460)$的神秘面纱。我们已经证明 $X_0(2900)$ 可以很好地接受为 $I(J^P)=0(0^+)$ $\bar{D}^*K^*$ 强子分子。它的观察还可以给出由 $\left(\bar{D},\bar{D}^*\right)$ 双峰和 $K^*$ 介子形成的整个重夸克对称多重态。除了 $X_0(2900)$，还有两个额外的 $I(J^P)=0(1^+)$ 强子分子与 $\bar{D}K^*$ 和 $\bar{D }^*K^*$ 通道以及一个额外的 $I(J^P)=0(2^+)$ $\bar{D}^*K^*$ 分子。在轻夸克极限下，它们是 36 美元。