Abstract The rare four-fold decay Bs → K* (→ Kπ) μ+μ−, governed by the flavor-changing neutral current transition b → dμ+μ−, provides a sensitive probe for testing the Standard Model (SM) and investigating signatures of new physics (NP). This work presents a comprehensive model-independent analysis of the decay using the framework of the weak effective field theory. We compute a set of key physical observables, including the differential branching ratio, forward-backward asymmetry, longitudinal polarization fraction, and several normalized angular coefficients 〈Ii〉, as a function of the dilepton invariant mass squared q2. The impact of NP is explored via both one-dimensional (1D) and two-dimensional (2D) scenarios involving NP Wilson coefficients C₇^NP, C₉^ () NP, and C₁₀^ () NP. Our findings reveal notable deviations from the SM predictions across multiple observables. Furthermore, we analyze the correlations between different observables and their 2D contour plots which would be useful to further constrain the parametric space of possible NP contributions. This study reinforces the potential of Bs → K*μ+μ− decay as a complementary channel in the search for physics beyond the SM.
Aarfi et al. (Thu,) studied this question.