Angular analysis of Bs → f′2 (1525) (→ K+ K−) μ+μ− decays as a probe to lepton flavor universality violation

The flavor anomalies reported in RK, RK∗, P′5, and B (Bs → ϕμ+μ−) indicate lepton flavor universality violation in b → sl+l− quark level transition decays. The deviation from the standard model prediction reported in the underlying flavor observables currently stands at the level of 2.5σ, 2.4σ, 3.3σ, and 3.7σ, respectively. In this context, we perform an angular analysis of the four-body differential decay of Bs → f′2 (1525) (→ K+ K−) μ+μ− in a model independent effective field theory framework. The decay mode B s → f'2 (1525) l+l− undergoes similar b → s neutral current quark level transition and, in principle, can provide complementary information regarding lepton flavor universality violation in b → sl+l− quark level transition decays. We give predictions of various physical observables such as the branching ratio, the longitudinal polarization fraction, the forward-backward asymmetry, the angular observables P1, P2, P′4, P′5, and also the lepton flavor sensitive observables such as the ratio of branching ratio R f′2, QFL, QAFB, Q1, Q2, Q′4, Q′5 for the Bs → f′2 (1525) (→K+K−) μ+μ− decay mode in the standard model and in the presence of several one-dimensional and two-dimensional new physics scenarios.