We present a search for the decay $B^+ \rightarrow a_1^+(1260) K^{ *0}(892)$. The data, collected with the \mbox{ \slshape B\kern-0.1em{ \smaller A}\kern-0.1em B\kern-0.1em{ \smaller A\kern-0.2em R}} detector at the SLAC National Accelerator Laboratory, represent 465 million $B\overline{ B}$ pairs produced in $e^+e^-$ annihilation at the energy of the $\Upsilon(4s)$. We find no significant signal and set an upper limit at 90\%\ confidence level on the product of branching fractions { \cal B}(B^+ \rightarrow a_1^+(1260) K^{ *0}(892)) \times { \cal B}(a_1^+(1260) \rightarrow \pi^+ \pi^- \pi^+) of $1.8 \times 10^{ -6}$.
Categories: hep-ex