论文标题
在$ u_a(1)$异常引起的单一重型重子中抑制衰减宽度
Suppression of decay widths in singly heavy baryons induced by the $U_A (1)$ anomaly
论文作者
论文摘要
我们根据参考文献中提出的diquark图片,使用有效的手性拉格朗日来研究激发单一重型重幸运子(SHB)的强烈而辐射的衰变。 [1]。有效的Lagrangian包含一个$ U_A(1)$异常术语,该术语诱导奇怪的和非震动SHB之间的反向质量顺序,并具有旋转式的$ 1/2^ - $。我们发现,$ u_a(1)$异常的效果与风味对称破坏的效果改变了Goldberger-treiman的关系,以质量差异$λ_Q(1/2^+)$及其chiral伙伴$λ_Q(1/2^ - )$,以及$λ_Q($λ_Q(1/2^-2^-2^-2^-2^ - )λINS,抑制$λ_q(1/2^ - )\toλ_q(1/2^+)η$的衰减宽度的抑制。我们还研究了其他各种衰落,例如$λ_q(1/2^ - )\ toσ_q(1/2^+,\,3/2^+)π$,$λ_q(1/2^ - )\toσ_q(1/2^+)π$,$λ_q(1/2^+) γ$,和$λ_Q(1/2^ - )\toλ_q(1/2^+)π^0 $,用于$λ_Q(1/2^ - )$的质量范围。
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 $Λ_Q (1/2^+)$ and its chiral partner $Λ_Q (1/2^-)$, and $Λ_Q (1/2^-) Λ_Q (1/2^+) η$ coupling, which results in suppression of the decay width of $Λ_Q (1/2^-) \to Λ_Q (1/2^+) η$. We also investigate the other various decays such as $Λ_Q (1/2^-) \to Σ_Q (1/2^+, \, 3/2^+) ππ$, $Λ_Q (1/2^-) \to Σ_Q (1/2^+) π$, $Λ_Q (1/2^-) \to Σ_Q (1/2^+, \, 3/2^+) γ$, and $Λ_Q (1/2^-) \to Λ_Q (1/2^+) π^0$ for wide range of mass of $Λ_Q (1/2^-)$.