Study of b-hadron decays to Λ+𝑐�ℎ−ℎ′− final states

Abstract

Decays of Ξ−𝑏 and Ω−𝑏 baryons to Λ+𝑐ℎ−ℎ′− final states, with h−h′− being π−π−, K−π− and K−K− meson pairs, are searched for using data collected with the LHCb detector. The data sample studied corresponds to an integrated luminosity of 8.7 fb−1 of pp collisions collected at centre-of-mass energies 𝑠√ = 7, 8 and 13 TeV. The products of the relative branching fractions and fragmentation fractions for each signal mode, relative to the 𝐵−→Λ+𝑐𝑝⎯⎯⎯𝜋− mode, are measured, with Ξ−𝑏→Λ+𝑐𝐾−𝜋− , Ξ−𝑏→Λ+𝑐𝐾−𝐾− and Ω−𝑏→Λ+𝑐𝐾−𝐾− decays being observed at over 5 σ significance. The Ξ−𝑏→Λ+𝑐𝐾−𝜋− mode is also used to measure the Ξ−𝑏 production asymmetry, which is found to be consistent with zero. In addition, the 𝐵−→Λ+𝑐𝑝⎯⎯⎯𝐾− decay is observed for the first time, and its branching fraction is measured relative to that of the 𝐵−→Λ+𝑐𝑝⎯⎯⎯𝜋− mode.