New physics effects in $R(K^{(*)})$, $B_s\to\mu^+\mu^-$, and $B^+\to K^+\nu{\bar\nu}$

Abstract

We analyze possible new physics (NP) effects on $b\to s$ transition processes, $R(K^{(*)})$, $B_s\to\mu^+\mu^-$, and $B^+\to K^+\nu{\bar\nu}$ decays. Though recent data for $R(K^{(*)})$ and ${\rm Br}(B_s\to\mu^+\mu^-)$ are compatible with the standard model (SM), there are still rooms for NP beyond the SM. Especially ${\rm Br}(B^+\to K^+\nu{\bar\nu})$ is measured to exceed the theoretical predictions. We parameterize the NP effects in a generic way with explicit NP scale $M_{\rm NP}$ and some possible powers of it. For reasonable ranges of NP fermionic couplings we find a window of $3.17~{\rm TeV} \le M_{\rm NP}\le 14.9~{\rm TeV}$ for new particles. When including ${\rm Br}(B^+\to K^+\mu^+\mu^-)$ and the angular observable $P_5'(B^+\to K^{*+}\mu^+\mu^-)$ we have a wider range of the window. Implications of our analysis about specific NP models are discussed.