论文标题
浓缩味的hadronic弱衰变的迷人和底部的重子
Heavy-Flavor-Conserving Hadronic Weak Decays of Charmed and Bottom Baryons
论文作者
论文摘要
三十年前，重型味（HFC）较重的重男性重质（例如$ξ_q\toλ_qπ$和$ω_q_q\toξ_qπ$ for $ q = c，b $ c = c，b $都已在结合了繁重的Quark和Chiral Symmetries的框架内研究了B $。可以指出的是，如果HFC过程中的沉重夸克作为观众，那么$ p $ - 波振幅为$ {\ cal b} _ {\ bar 3} \ to {\ cal b} _ {\ cal b} _ {\ bar 3}+π$，twith $ {\ b} $ {\ cal 3}夸克限制。确实，对于$ξ_b\toλ_bπ$衰减而言，情况就是这种情况。对于$ξ_c\toλ_cπ$衰减，他们会通过$ CS \ to dc $ transition获得$ w $ - 交换图引起的其他非光谱贡献。观众和非镜头$ W $ -Exchange对$ S $ - 波振幅的贡献为$ξ_c\toλ_cπ$具有破坏性，使$ s $ - 波的贡献甚至更小。但是，在所有先前的模型计算中都忽略了对$ p $ - 波振幅的效果，直到在组成夸克模型的框架内进行了最新的调查，在$ξ_c\toλ_cπ$衰减中，发现平等的极点术语在$ξ_c\ to $ξ_c\ to to pole上占主导地位。由于HFC过程中生产的触发性很软，因此我们应用当前代数来研究$ s $ - 和$ p $ - 波振幅，并使用袋子和diquark型号来估算四夸克运营商的矩阵元素。我们确认，$ξ_c\toλ_cπ$衰减确实是由从nonpectator $ w $ -exchange引起的平等持续过渡主导的，并且它们从中级$σ_c$ pole pole term中获得了最大的贡献。我们还表明，$ s $ - $ω_b\ toξ_bπ$衰减在重夸克极限中消失，而$ω_c\ toξ_cπ$接收到额外的$ w $ -exChange通过$ cs \ to dc $ transition。
Three decades ago, heavy-flavor-conserving (HFC) weak decays of heavy baryons such as $Ξ_Q\toΛ_Qπ$ and $Ω_Q\toΞ_Qπ$ for $Q=c,b$ had been studied within the framework that incorporates both heavy-quark and chiral symmetries. It was pointed out that if the heavy quark in the HFC process behaves as a spectator, then the $P$-wave amplitude of ${\cal B}_{\bar 3}\to {\cal B}_{\bar 3}+π$ with ${\cal B}_{\bar 3}$ being an antitriplet heavy baryon will vanish in the heavy quark limit. Indeed, this is the case for $Ξ_b\toΛ_b π$ decays. For $Ξ_c\toΛ_cπ$ decays, they receive additional nonspectator contributions arising from the $W$-exchange diagrams through the $cs\to dc$ transition. Spectator and nonspectator $W$-exchange contributions to the $S$-wave amplitude of $Ξ_c\toΛ_cπ$ are destructive, rendering the $S$-wave contribution even smaller. However, the nonspectator effect on the $P$-wave amplitude was overlooked in all the previous model calculations until a very recent investigation within the framework of a constituent quark model in which the parity-conserving pole terms were found to be dominant in $Ξ_c\toΛ_cπ$ decays. Since the pion produced in the HFC process is soft, we apply current algebra to study both $S$- and $P$-wave amplitudes and employ the bag and diquark models to estimate the matrix elements of four-quark operators. We confirm that $Ξ_c\toΛ_cπ$ decays are indeed dominated by the parity-conserving transition induced from nonspectator $W$-exchange and that they receive largest contributions from the intermediate $Σ_c$ pole terms. We also show that the $S$-wave of $Ω_b\to Ξ_b π$ decays vanishes in the heavy quark limit, while $Ω_c\to Ξ_cπ$ receive additional $W$-exchange contributions via $cs\to dc$ transition.
