Heavy-flavor-conserving hadronic weak decays of heavy baryons

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 Xi(-)(b) -> Lambda(0)(b)pi(-) by LHCb recently, we have reexamin Xi(-)(b) -> Lambda(0)(b)pi(-) 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 Xi(c)-> Lambda(c)pi is predicted to be of order 10(-4). It is suppressed relative to B(Xi(b) -> Lambda(b)pi) owing to the shorter lifetime of Xi(c) relative to Xi(b) and the destructive nonspectator W-exchange contribution. The kinematically accessible weak decays of the sextet heavy baryon Omega(Q) are Omega(Q) -> Xi(Q)pi. Due to the absence of the B-6 - B-(3) over bar transition in the heavy quark limit and the B-6 - B-6 transition in the model calculations, Omega(Q) -> Xi(Q)pi vanish in the heavy quark limit.