Reevaluating Uncertainties in $\bar{B}\rightarrow X_s\gamma$

Abstract

The rare inclusive decay $\bar{B}\rightarrow X_s\gamma$ is an important probe of physics beyond the standard model. The largest uncertainty on the decay rate and CP asymmetry comes from operators that appear at order $1/m_b$ in the heavy quark expansion. One of the three leading contributions in the heavy quark expansion, $Q_1^q-Q_{7\gamma}$ is described by a non-local function whose moments are related to HQET parameters. We use recent progress in our knowledge of these parameters to better constrain their contributions to the total rate and CP asymmetry.