Speaker
Description
We consider the combined measurements of CP-averaged decay rates and direct CP asymmetries of B±→K±ℓ+ℓ− and B±→π±ℓ+ℓ− to probe (non-local) four-quark operator matrix element contributions to rare semileptonic B meson decays. We also explore how their effects could be in principle disentangled from possible local new physics effects. We construct a ratio of CP-odd decay rate differences which are exactly predicted within the standard model in the U-spin limit. Our results motivate binned measurements of the direct CP asymmetry in B±→π±ℓ+ℓ− as well as dedicated theoretical estimates of U-spin breaking both in local form factors as well as in four-quark matrix elements.
For B → K mumu we show that possible NP phase in C9 Wilson coefficient can be tested by measuring the direct CP-asymmetry. We show that this asymmetry is enhanced around the peak of each ccbar-resonance, and in fact more pronounced in the close vicinity of J/ψ and ψ(2S). Therefore, measuring ACP below and above the resonances' peak could be revelatory of the CP-violation that originates from beyond the Standard Model, or to be a significant constrain when building a realistic scenario of New Physics.
