We study strong and radiative decays of excited singly heavy baryons (SHBs) using an effective chiral Lagrangian based on the diquark picture proposed in Ref. [1]. The effective Lagrangian contains a $U_A (1)$ anomaly term, which induces an inverse mass ordering between strange and non-strange SHBs with spin-parity $1/2^-$. We find that the effect of the $U_A (1)$ anomaly combined with flavor-symmetry breaking modifies the Goldberger-Treiman relation for the mass difference between the ground state $\Lambda_Q (1/2^+)$ and its chiral partner $\Lambda_Q (1/2^-)$, and $\Lambda_Q (1/2^-) \Lambda_Q (1/2^+) \eta$ coupling, which results in suppression of the decay width of $\Lambda_Q (1/2^-) \to \Lambda_Q (1/2^+) \eta$. We also investigate the other various decays such as $\Lambda_Q (1/2^-) \to \Sigma_Q (1/2^+, \, 3/2^+) \pi \pi$, $\Lambda_Q (1/2^-) \to \Sigma_Q (1/2^+) \pi$, $\Lambda_Q (1/2^-) \to \Sigma_Q (1/2^+, \, 3/2^+) \gamma$, and $\Lambda_Q (1/2^-) \to \Lambda_Q (1/2^+) \pi^0$ for wide range of mass of $\Lambda_Q (1/2^-)$.

中文翻译：

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UA(1)异常引起的单重重子衰变宽度的抑制

我们使用基于参考文献中提出的迪夸克图片的有效手性拉格朗日函数研究激发的单重重子 (SHB) 的强辐射衰变。[1]。有效拉格朗日量包含一个 $U_A (1)$ 异常项，它在自旋奇偶性 $1/2^-$ 的奇怪和非奇怪 SHB 之间引起反质量排序。我们发现 $U_A (1)$ 异常与风味对称性破坏相结合的影响修改了基态 $\Lambda_Q (1/2^+)$ 与其手性伙伴 $ 之间质量差异的 Goldberger-Treiman 关系\Lambda_Q (1/2^-)$ 和 $\Lambda_Q (1/2^-) \Lambda_Q (1/2^+) \eta$ 耦合，从而抑制了 $\Lambda_Q (1 /2^-) \to \Lambda_Q (1/2^+) \eta$。我们还研究了其他各种衰减，例如 $\Lambda_Q (1/2^-) \to \Sigma_Q (1/2^+, \, 3/2^+) \pi \pi$，