Measurement of Λ_b⁰, Λ_c⁺, and Λ Decay Parameters Using Λ_b⁰ → Λ_c⁺h^- Decays

A comprehensive study of the angular distributions in the bottom-baryon decays Λ_b⁰ → Λ_c⁺h^- (h = π; K), followed by Λ_c⁺ → Λh⁺ with Λ → pπ⁻ or Λ_c⁺ → pK_S⁰ decays, is performed using a data sample of proton-proton collisions corresponding to an integrated luminosity of 9 fb⁻¹ collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV. The decay parameters and the associated charge-parity (CP) asymmetries are measured, with no significant CP violation observed. For the first time, the Λ_b⁰ → Λ_c⁺h^- decay parameters are measured. The most precise measurements of the decay parameters α, β, and γ are obtained for Λ_c⁺ decays and an independent measurement of the decay parameters for the strange-baryon Λ decay is provided. The results deepen our understanding of weak decay dynamics in baryon decays.