An empirical model of the long-distance contributions to $\bar{B}^{0} \rightarrow \bar{K}^{*0}\mu^{+}\mu^{-}$ transitions

Understand

A method for analysing the hadronic resonance contributions in $\bar{B}^{0} \rightarrow \bar{K}^{*0}\mu^{+}\mu^{-}$ decays is presented.

• This method uses an empirical model that relies on measurements of the branching fractions and polarisation amplitudes of final states involving $J^{PC}=1^{--}$ resonances, relative to the short-distance component, across the full dimuon mass spectrum of $\bar{B}^{0} \rightarrow \bar{K}^{*0}\mu^{+}\mu^{-}$ transitions.
• The model is in good agreement with existing calculations of hadronic non-local effects.
• The effect of this contribution to the angular observables is presented and it is demonstrated how the narrow resonances in the $q^{2}$ spectrum provide a dramatic enhancement to $CP$-violating effects in the short-distance amplitude.