$b \rightarrow s \gamma$ AND $b \rightarrow s g$: A THEORETICAL REAPPRAISAL

Abstract

We present upgraded theoretical predictions for inclusive and exclusive radiative decays of {\it B} mesons. Our results include those next-to-leading order corrections that have already been computed. Our best estimates in the Standard Model are $BR(B \rightarrow K^* \gamma)=(4.3 \pm 0.9^{ +1.4}_{-1.0}) \times 10^{-5}$, $BR(B \rightarrow X_s \gamma) =(1.9 \pm 0.2\pm 0.5) \times 10^{-4}$, $\Gamma(B \rightarrow K^* \gamma)/ \Gamma(B \rightarrow X_s \gamma)=0.23 \pm 0.09$ and $BR(B \rightarrow X_s g)= (1.57 \pm 0.15 ^{+0.86}_{-0.59} \pm 0.23) \times 10^{-3}$. We also consider limits found with two-Higgs-doublet models.