Alessandro Boschetti

21 January 2023
59th International Winter Meeting on Nuclear Physics

Abstract: Bottomonium spectroscopy offers excellent opportunities for insights on the behavior of QCD in the non-perturbative regime. In order to guide theorists through the difficult task of modeling non-perturbative QCD phenomena, the experimental measurement of masses, widths, and transition rates of bb¯ states is crucial. Recent analyses of Belle and Belle II data samples unveiled unexpected results in this field, such as the observation of anomalous transition rates and of new states that challenge the conventional description of bb¯ mesons. In particular, the newly observed state identified as Y(10753) is generating a big interest among theorists concerning its interpretation. The bb¯ spectroscopy is thus encouraging the birth of a variety of new theoretical models. The latter include the contribution of hadronic loops, or the existence of exotic states such as compact tetraquarks, hadrobottomonia and hybrids. Belle II has the unique opportunity to analyze the 19 fb−1 data sample collected with a scan near √s=10.75 GeV, in order to provide experimental results in this sector. The talk will thus be focused on the recent Belle II results with the scan data and related prospects.

Note: 20'