Tomoko Iwashita (Nara Women's Univ.)
It has been nearly ten years since the narrow $X(3872)$ state has been discovered in charged $B$ decays by the Belle experiment and its nature still remains unclear. To provide further insight on its properties, we report the search for the $X(3872)$ in the decays $B \to X(3872) K \pi$, $X(3872) \to J/\psi \pi^+ \pi^-$. The analysis is based on full data sample collected at the $\Upsilon(4S)$ with the Belle detector at the KEKB collider.
Prof. Youngjoon Kwon (Yonsei University)