Measurement of the direct $CP$ asymmetry in the $B_d^0\to K^{*0}\gamma$decay

The direct $CP$ asymmetry in the radiative decay $B_d^0\to K^{*0}\gamma$ has been measured using $1.0\,fb^{-1}$ of $pp$ collisions collected by the LHCb experiment. The value obtained, \begin{equation} \mathcal{A}_{CP}(B_d^0\to K^{*0}\gamma) = 0.008\pm0.017\mathrm{(stat)}\pm0.009\mathrm{(syst)},\nonumber \end{equation} is the most precise measurement to date.