Recent $B$ physics results from Belle II

10 Jun 2026, 09:25
25m
Scuola Normale Superiore, Aula Dini, Palazzo del Castelletto (Pisa)

Scuola Normale Superiore, Aula Dini, Palazzo del Castelletto

Pisa

Via del Castelletto, 11, 56126 Pisa PI

Speaker

Jim Libby

Description

The Belle and Belle II experiments have collected a $1.2~\mathrm{ab}^{-1}$ sample of $e^+ e^-\to B\bar{B}$ collisions at a center-of-mass energy corresponding to the $\Upsilon(4S)$ resonance. We present measurements of the ratios for exclusive $B\to D^{(*)}\ell \nu$ decays $R(D^{(*)})$ in decays where the other $B$ in the event is reconstructed in hadronic or semileptonic final states. We also present recent results on $B\to K^{(*)}\nu\bar{\nu}$ using an inclusive tagging technique, including the first results from Belle. We will also present a search for inclusive decays $B\to X_s\nu\bar{\nu}$, where $X_s$ is a hadronic system with strangeness. We will also present searches for the decays $B^+\to K^+\tau^+\tau^-$ and $B^0\to K^0_S\tau^+\tau^-$. The asymmetric-energy SuperKEKB collider provides a boost to the $B$ mesons in the laboratory frame, allowing measurements of time-dependent $C\!P$ violation. We present measurements of time-dependent $C\!P$ violation in both hadronic and radiative penguin $B$ decays, including measurements of the $C\!P$ asymmetries in $B\to \eta' K^0$, and the radiative decays $B\to \rho^0\gamma$ and $B\to K^0 \pi^0 \gamma$.

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Author

Jim Libby

Co-author

Steven Robertson (University of Alberta)

Presentation materials