Related papers: First flavor tagging calibration using 2019 Belle …
$B^0_d$-$\bar{B}{}^0_d$ oscillations are observed in ``self-tagged'' samples of partially reconstructed $B$ mesons decaying into a lepton and a charmed meson collected in $p\bar p$ collisions at $\sqrt{s} = 1.8$ TeV. A flavor tagging…
The Belle II experiment at the SuperKEKB energy-asymmetric $e^+ e^-$ collider is a substantial upgrade of the B factory facility at the Japanese KEK laboratory. The design luminosity of the machine is $8\times 10^{35}$ cm$^{-2}$s$^{-1}$ and…
The Belle II / SuperKEKB experiment is an $e^+e^-$ collider running at the $\Upsilon(4S)$ resonance energy to produce B meson pairs. As an upgrade of the Belle / KEKB experiment, it will start physics data taking from 2018 and with $\sim…
A new algorithm for the determination of the initial flavour of $B_s^0$ mesons is presented. The algorithm is based on two neural networks and exploits the $b$ hadron production mechanism at a hadron collider. The first network is trained…
We report a measurement of the $B^0-\bar{B}^0$ mixing parameter $\Delta m_d$ based on a $\rm 29.1~fb^{-1}$ sample of $\Upsilon (4S)$ resonance decays collected by the Belle detector at the KEKB asymmetric $e^+ e^-$ collider. We use events…
We report on preliminary measurements of branching fractions, charge-parity-violating asymmetries, and longitudinal polarization fractions in charmless bottom-meson decays from the Belle~II experiment. We use samples of electron-positron…
The Belle II detector operating at the future upgrade to the KEKB accelerator will perform high-statistics precision investigations into the flavor sector of the Standard Model. As charged hadron identification is a vital element of the…
The Belle II experiment at the SuperKEKB energy-asymmetric electron-positron collider is a substantial upgrade of the B factory facility at the Japanese KEK laboratory. Belle II collected a sample of $362~\mathrm{fb}^{-1}$ at the…
The Belle II experiment's ability to identify particles critically affects the sensitivity of its measurements. We describe Belle II's algorithms for identifying charged particles and evaluate their performance in separating pions, kaons,…
This proceeding summarises recent studies on semileptonic and leptonic $B$ decays, which provide stringent tests of lepton flavour universality as well as key experimental inputs to ultimately increase the precision of inclusive $|V_{ub}|$…
Identifying the flavour of neutral $B$ mesons production is one of the most important components needed in the study of time-dependent $CP$ violation. The harsh environment of the Large Hadron Collider makes it particularly hard to succeed…
We report on the first Belle II measurement of the branching fraction ($\mathcal{B}$) and longitudinal polarization fraction ($f_L$) of $B^+\to \rho^+\rho^0$ decays. We reconstruct $B^+\to \rho^+(\to \pi^+\pi^0(\to \gamma\gamma))\rho^0(\to…
We measure the branching fraction of B- -> tau- nu_tau-bar using the full Upsilon(4S) data sample containing 772*10^6 BBbar pairs collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. Events with BBbar pairs are…
We present the first evidence of the decay B- --> tau- nu_tau-bar using 414 fb^-1 of data collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. Events are tagged by fully reconstructing…
The ratio of branching fractions $R(D^{*}) = \mathcal{B}(\overline{B} \rightarrow D^{*} \tau^{-} \overline{\nu}_{\tau})$/$\mathcal{B} (\overline{B} \rightarrow D^{*} \ell^{-} \overline{\nu}_{\ell})$, where $\ell$ is an electron or muon, is…
The Belle II experiment at the SuperKEKB energy-asymmetric $e^+e^-$ collider is a substantial upgrade of the B factory facility at the Japanese KEK laboratory. The design luminosity of the machine is $8\times10^{35}\,…
High precision flavor physics measurements are an essential complement to the direct searches for new physics at the LHC. Such measurements can be performed at an upgraded KEKB accelerator. The status of the SuperKEKB collider and Belle II…
The CKM angle $\gamma/\phi_{3}$ is the only one that is accessible with tree level decays in a theoretically clean way such that it provides a precision test of $CP$ violation in the standard model. The Belle II experiment is a substantial…
The Belle II experiment has been preparing for its first e+ e- collisions, scheduled in April 2018. With a target luminosity 40 times greater than the Belle experiment, the goal of Belle II is to open the door to a panorama of measurements…
With 6.2 fb^-1 of data collected on the Upsilon(4S), Belle reports its first measurement of sin 2\phi_1 = 0.45^{+0.43}_{-0.44}(stat)^{+0.07}_{-0.09}(sys). The result was obtained by fitting the proper time distribution of flavor tagged and…