Continuing search for new physics in b → sμμ decays: two operators at a time

The anomalies in the measurements of observables involving b -> s decays, namely RK, RK, P05, and B s, may be addressed by adding lepton-universality-violating new physics contributions to the e ff ective operators O9;O10;O09;O0 10. We analyze all the scenarios where the new physics contributes to a pair of these operators at a time. We perform a global fi t to all relevant data in the b -> s sector to estimate the corresponding new Wilson coe ffi cients, CNP 9;CNP 10;C09;C0 10. In the light of the new data on RK and RK presented in Moriond 2019, we fi nd that the scenarios with new physics contributions to the (CNP 9, C09) or (CNP 9, C0 10) pair remain the most favored ones. On the other hand, though the competing scenario (CNP 9, CNP 10) remains attractive, its advantage above the SM reduces signi fi cantly due to the tension that emerges between the RK and RK measurements with the new data. The movement of the RK measurement towards unity would also result in the re-emergence of the one-parameter scenario C-9(NP) = -C-9'.