The SU(2)L×U(1)Y invariance of the Standard Model effective field theory (SMEFT) imposes relations among different low-energy effective field theory Wilson coefficients (WCs), any deviations from which would signal the presence of physics beyond SMEFT. In this work, we investigate two such relations (CS=−CP, CS′=CP′) among the scalar and the pseudoscalar new physics WCs that can contribute to b→sττ processes. We show that, even when new physics violating these relations would not be measurable in the branching ratios of Bs→τ+τ− and B→K(*)τ+τ− at HL-LHC and FCC-ee, it can still manifest itself in the angular distribution of B→K*0τ+τ−. We identify the combinations of angular observables in this decay channel that are sensitive to scenarios beyond SMEFT. We find that the two observables S6c and A7, and their combination, have the potential to identify physics beyond SMEFT.
Published by the American Physical Society
2024