Study of Exclusive Radiative $\mathit{B}$ Meson Decays

We have studied exclusive, radiative $B$ meson decays to charmless mesons in $9.7\times {10}^6$ $B\overline{B}$ decays accumulated with the CLEO detector. We measure $B(B^0\to K^{*0\mathrm{}}(892\left)\gamma \right)=({4.55}_{-0.68\mathrm{}}^{+0.72\mathrm{}}\pm 0.34)\times {10}^{-5\mathrm{}}$ and $B(B^{+}\to K^{*+}(892\left)\gamma \right)=({3.76}_{-0.83\mathrm{}}^{+0.89\mathrm{}}\pm 0.28)\times {10}^{-5\mathrm{}}$. We have searched for $\mathrm{CP}$ asymmetry in $B\to K^{*}\left(892\right)\gamma$ decays and measure $A_{\mathrm{CP}}=+0.08\mathrm{}\pm 0.13\pm 0.03$. We report the first observation of $B\to K_2^{*}\left(1430\right)\gamma$ decays with a branching fraction of $({1.66}_{-0.53\mathrm{}}^{+0.59\mathrm{}}\pm 0.13)\times {10}^{-5\mathrm{}}$. No evidence for the decays $B\to \rho \gamma$ and $B^0\to \omega \gamma$ is found and we limit $B(B\to (\rho /\omega \left)\gamma \right)/B(B\to K^{*}(892\left)\gamma \right)<0.32\mathrm{}$ at $90\%$ C.L.