Angular Analysis of ${\varLambda }^{0}_{{b} } \rightarrow \varLambda {\mu }^{+}{\mu }^{-}$ Decays

Abstract

The angular distribution of ${\varLambda }^{0}_{{b} } \rightarrow \varLambda {\mu }^{+}{\mu }^{-}$ decays can be described as a function of three angles and ${q}^{2}$ when neglecting the production polarisation of the ${\varLambda }^{0}_{{b} }$. The two angles that are relevant for the analysis in this chapter and are defined in Fig. 4.1: $\theta _\ell$ is the angle between the positive (negative) muon direction in the dimuon rest frame and the dimuon system direction in the ${\varLambda }^{0}_{{b} }$ (${\overline{\varLambda }}^{0}_{{b} }$) rest frame; similarly, $\theta _h$ is defined as the angle between the proton and the $\varLambda$ baryon directions, in the $\varLambda$ and ${\varLambda }^{0}_{{b} }$ rest frames.