paper

Heavy-Flavor-Conserving Hadronic Weak Decays of Heavy Baryons

arXiv:1512.01276 · doi:10.1007/JHEP03(2016)028

Abstract

More than two decades ago, we studied heavy-flavor-conserving weak decays of heavy baryons within the framework that incorporates both heavy-quark and chiral symmetries. In view of the first observation of $I^_{b}^{-} \to I^_{b}^{0} I ¨ ^{-}$ by LHCb recently, we have reexamined these decays and presented updated predictions. The predicted rates for $I^_{b}^{-} \to I^_{b}^{0} I ¨ ^{-}$ in the MIT bag and diquark models are consistent with experiment. The major theoretical uncertainty stems from the evaluation of baryon matrix elements. The branching fraction of $I^_{c} \to I^_{c} I ¨ $ is predicted to be of order $1 0^{- 4}$ . It is suppressed relative to $B r (I^_{b} \to I^_{b} I ¨ )$ owing to the shorter lifetime of $I^_{c}$ relative to $I^_{b}$ and the destructive nonspectator $W$ -exchange contribution. The kinematically accessible weak decays of the sextet heavy baryon $I^c ◯_{Q}$ are $I^c ◯_{Q} \to I^_{Q} I ¨ $ . Due to the absence of the $B_{6} - B_{3 ˉ}$ transition in the heavy quark limit and the $B_{6} - B_{6}$ transition in the model calculations, $I^c ◯_{Q} \to I^_{Q} I ¨ $ vanish in the heavy quark limit.

11 pages, to appear in JHEP