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 Λ0𝑏 →Λ+𝑐⁢ℎ−⁡(ℎ =𝜋,𝐾), followed by Λ+𝑐 →Λ⁢ℎ+ with Λ →𝑝⁢𝜋− or Λ+𝑐 →𝑝⁢𝐾0S 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 (𝐶⁢𝑃) asymmetries are measured, with no significant 𝐶⁢𝑃 violation observed. For the first time, the Λ0𝑏 →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.