Recent Hadron Spectroscopy Results from the Belle and Belle II experiments

Abstract

The Belle~II experiment, the major upgrade of the Belle detector, is currently collecting data at the SuperKEKB asymmetric-energy $e^+e^-$ collider in Tsukuba, Japan. With an integrated luminosity of 575\,fb$^{-1}$, Belle~II has already surpassed the maximum luminosity accumulated by both BaBar and Belle. Recent analyses combining Belle and Belle~II data sets have delivered results of unprecedented precision, demonstrating the strong potential of the unified data sample, which now exceeds 1.5\,ab$^{-1}$. In this contribution, recent advances in hadron spectroscopy are presented. Highlights include new results in bottomonium and charmonium physics, with particular emphasis on the structure of the $Υ(10753)$, searches for hidden-charm and hidden-strangeness pentaquarks, and the latest developments in baryon spectroscopy, including studies of the $Ω(2012)$ and excited $Λ_c$ states. Prospects for future spectroscopy analyses exploiting the full Belle and Belle~II data sets are also discussed.