Speaker
Description
In the pursuit of physics beyond the Standard Model, a promising path is the study of exclusive B-meson decays caused by the transition b→sℓ+ℓ−. A key observable in such decays is the ratio $R_K$, which measures electron-muon universality in B→Kμ+μ−/e+e-. At first sight, the recent LHCb measurement of RK ~ 1 may seem to largely constrain deviations from universality in these decays. However, this is actually not the case: new sources of CP violation allow for universality violation consistent with $R_K = 1$ [2303.08764]. Another central observable is the branching ratio of the semileptonic decay B→Kμ+μ−, which shows a ~4σ tension between experiment and theory. New physics causing this tension is customarily encoded in the Wilson coefficients $C_9$ and $C_{10}$. We discuss a new way to extract CP-violating phases in these coefficients [2212.09575]. We also discuss CP violation in the leptonic decay Bs→μ+μ−, which complements semileptonic decays through its outstanding sensitivity to scalar and pseudoscalar physics. These studies provide exciting new opportunities to search for new physics in rare B-meson decays.
