Status of SM Calculations of b to s Transitions

Abstract

We report recent progress in SM calculations of b → s transitions. We discuss the first NNLL prediction of theB → Xsγ branching ratio, including important additional subtleties due to nonperturbative corrections and logarithmically-enhanced cut effects, and also recent results on the inclusive modeB → Xsℓ + ℓ − . Moreover, new results on the corresponding exclusive modes are reviewed. Finally, we comment on the present status of the so-called B → Kπ puzzle in hadronic b → s transitions.

Large hadronic power corrections or new physics in the rare decay B → K ∗ μ + μ −?

“…In contrary to the exclusive decay, for the inclusive case, the power corrections can be theoretically estimated (see refs. [19][20][21] for reviews). However, there are options to resolve the puzzle before Belle II:…”

Stringy explanation of b → sℓ + ℓ − anomalies

“…Global fits of the Wilson coefficients to the available b → s + − data have been performed by different groups, with varying statistical methods and treatments of hadronic uncertainties [39][40][41][42][43][44][45][46][47]. Notably, the observed pattern of deviations in b → s + − transitions seems to hint towards a consistent interpretation in terms of new physics.…”

New observables in the decay mode B̄d→ K̄*0ℓ+ℓ−

“…Rare B and kaon decays (for reviews see [1,2,3]) representing loop-induced processes are highly sensitive probes for new degrees of freedom beyond the Standard Model (SM) and will be used when making indirect searches for these unknown effects. It is well-known that the indirect constraints on new physics (NP) from the present flavour data indicate a NP scale much higher than the electroweak scale when such new effects are naturally parameterised by higher-dimensional operators.…”