From Ξb → Λb π to Ξc → Λc π

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Using a successful framework for describing S-wave hadronic decays of light hyperons induced by a subprocess s → u (u d), we presented recently a model-independent calculation of the amplitude and branching ratio for Ξ-b → Λb π- in agreement with a LHCb measurement. The same quark process contributes to Ξ⁰c → Λc π-, while a second term from the subprocess cs → cd has been related by Voloshin to differences among total decay rates of charmed baryons. We calculate this term and find it to have a magnitude approximately equal to the s → u (u d) term. We argue for a negligible relative phase between these two contributions, potentially due to final state interactions. However, we do not know whether they interfere destructively or constructively. For constructive interference one predicts B(Ξc⁰ → Λc π-) = (1.94 ± 0.70)× 10⁻³ and B(Ξc+ → Λc π⁰) = (3.86 ± 1.35)× 10⁻³. For destructive interference, the respective branching fractions are expected to be less than about 10⁻⁴ and 2 × 10⁻⁴.