Weimin Song

02 July 2024
Exotic Hadron Spectroscopy 2024

Abstract: The Belle and Belle~II experiments have collected a $1.4~\mathrm{ab}^{-1}$ sample of $e^+e^-$ collision data at centre-of-mass energies near the $\Upsilon(nS)$ resonances. These data include a 19.2~fb$^{-1}$ sample collected near the $\Upsilon(10753)$ resonance to probe its potentially exotic nature. We present several results related to the following processes: $e^+e-\to \Upsilon(nS)\eta$, $e^+e-\to \gamma X_b(\chi_{bJ}\pi^+\pi^-)$, $e^+ e^-\to h_b(1P)\eta$ and $e^+e^-\to\chi_{bJ}(1P)\omega$. The last analysis also includes data samples collected by Belle at similar centre-of-mass energies. In addition, we present Belle measurements of the $B^{0}$ and $B^+$ meson mass difference, a pentaquark search in $\Upsilon(1S)$ and $\Upsilon(2S)$ decays, as well as studies of $h_b(2P)$ decays to the $\eta \Upsilon(1S)$ and $\chi_{bJ}\gamma$ final states.