Speaker
Description
The large data sample accumulated by the Belle experiment at the KEKB asymmetric-energy e^{+} e^{-} collider provides a unique opportunity to perform studies related to hadron spectroscopy utilising various production mechanisms. We studied the two-photon process \gamma\gamma \to \gamma\psi(2S) is studied for the first time and found an evidence for a structure in the \gamma\psi(2S) invariant-mass distribution at 3921.3 \pm 2.4 \pm 1.6\,{\rm MeV}. We report the first measurement of exclusive cross sections for $e^{+}e^{-} \to B\bar{B}$, $e^{+}e^{-} \to B\bar{B}^{*}$, and $e^{+}e^{-} \to B^{*}\bar{B}^{*}$ in the energy range from $10.63$ to $11.02\,{\rm GeV}$. In addition, we report a search for the $\chi_{bJ}(nP)$ bottomonium states at Belle. Other studies on conventional or exotic charmoniuum and bottomoniuum are also presented.
