Observation of $X(3872)to J/psi gamma$ and search for $X(3872)topsigamma$ in B decays

We report a study of $Bto (J/psi gamma) K$ and $Bto (psi gamma)K$ decay modes using $772times 10^{6}$ $Bbar{B}$ events collected at the Upsilon(4S)$ resonance with the Belle detector at the KEKB energy-asymmetric $e^+ e^-$ collider. We observe $X(3872) to J/psi gamma$ and report the first evidence for $chi_{c2} to J/psi gamma$ in $Bto (X_{cbar{c}}gamma) K$ decays, while in a search for $X(3872) to psi gamma$ no significant signal is found. We measure the branching fractions, $mathcal{B}(B^{pm} to X(3872) K^{pm}) mathcal{B}(X(3872) to J/psigamma)$ $=$ $(1.78^{+0.48}_{-0.44}pm 0.12)times 10^{-6}$, $mathcal{B} (B^{pm} tochi_{c2} K^{pm})$$=$ $(1.11^{+0.36}_{-0.34} pm 0.09) times 10^{-5}$, $mathcal{B}(B^{pm} to X(3872) K^{pm}) mathcal{B}(X(3872) to psigamma)$ $<$ $3.45times 10^{-6}$ (upper limit at 90% C.L.) and also provide upper limits for other searches.