Two Topics in $b$ Physics

Abstract

(1) A simple transversity analysis permits one to separate the P-even and P-odd partial waves in such decays as $B_s \to J/ψϕ$ and $B \to J/ψK^*$. This method is relevant to the separation of contributions of CP-even and CP-odd final states in $B_s$ decays, and hence to the measurement of a possible lifetime difference between mass eigenstates. (2) The enhancement $ΔΓ(Λ_b)$ of the $Λ_b$ decay rate due to four-fermion processes is calculated in terms of the $Σ_b^* - Σ_b$ hyperfine splitting, the $B^* - B$ hyperfine splitting, and the $B$ meson decay constant $f_B$. Despite a relatively large hyperfine splitting observed by the DELPHI Collaboration, the mechanism falls far short of being able to explain the observed enhancement.