相关论文: Semileptonic B decay results from early Belle II d…

We report a measurement of the branching fraction of inclusive semileptonic $B$ meson decays $B\to X_c\ell\nu\ell$ in $\Upsilon(4S)\to B\bar B$~data recorded by the Belle II experiment at the SuperKEKB asymmetric-energy $e^+e^-$ collider…

We report measurements of the $\bar{B}^0 \to D^{*+} \ell^{-} \bar{\nu}_l$ and $B^- \to D^{0} \ell^{-} \bar{\nu}_l$ processes using 34.6 fb$^{-1}$ of collision events recorded by the Belle II experiment at the SuperKEKB asymmetric-energy…

The Belle II experiment operates at the SuperKEKB asymmetric-energy $e^+e^-$ collider. During the Run 1 data taking, we have collected an integrated luminosity of $424\text{ fb}^{-1}$ of collision data at the energy near the $\Upsilon (4S)$…

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 $|V_{ub}|$…

Time dependent CP-violation phenomena are a powerful tool to precisely measure fundamental parameters of the Standard Model and search for New Physics. The Belle II experiment at the SuperKEKB energy-asymmetric $e^+e^-$ collider is a…

We present a reconstruction of the semileptonic decays $B^0 \to \pi^- e^+ \nu_e$ and $B^+ \to \pi^0 e^+ \nu_e$ in a sample corresponding to 189.3 fb$^{-1}$ of Belle II data, using events where the partner $B$-meson is reconstructed from a…

Belle II is a Super $B$ Factory experiment, expected to record 50 ab$^{-1}$ of $e^+e^-$ collisions at the SuperKEKB accelerator until 2035. The large samples of $B$ mesons, charm hadrons, and tau leptons produced in the clean experimental…

We report a study of semileptonic B decays to P-wave D** mesons. Semileptonic decay to D*_2 meson is observed for the first time and its product branching ratio is measured to be Br(B+ -> anti-D*0_2 l+nu) x Br(anti-D*0_2 -> D- pi+) = 0.22…

We present an analysis of the semi-inclusive decays $B_s \to D_s^- X \ell^+ \nu$ and $B_s \to D_s^{*-} X \ell^+ \nu$, where $X$ denotes a final state that may consist of additional hadrons or photons and $\ell$ is an electron or muon. The…

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…

We report a preliminary study of the branching fractions and $q^2$ distributions of exclusive charmless semileptonic B decays, using events tagged by fully reconstructing one of the $B$ mesons in a hadronic decay mode. These results are…

The semileptonic $B$ meson decays of the type $B \to X_u \ell \nu$ are important for measuring the magnitude of the CKM matrix element $V_{ub}$. Recent measurements of inclusive $B \to X_u e \nu_e$ and hadronically tagged $B^0 \to \pi^-…

The Belle detector at the KEKB electron-positron collider has collected approximately 800 million Upsilon(4S) events in its decade of operation. The KEKB group has proposed Super-KEKB, an upgrade of KEKB to increase the luminosity by two…

The Belle II experiment at the SuperKEKB collider is an upgrade of the Belle / KEKB experiment. It will start physics data taking from 2018 and with $40$ times luminosity, its goal is to accumulate 50 $ab^{-1}$ of $e^+e^-$ collision data.…

We report a measurement of the charmless semileptonic decays $B^0 \to \pi^- / \rho^- \ell^{+} \nu$ and $B^+ \to \pi^0 / \rho^0 \ell^{+} \nu$, based on 253 fb$^{-1}$ of data collected with the Belle detector at the KEKB $e^+e^-$ asymmetric…

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…

We measure the branching fractions for the decays $\bar{B}^0 \to D^{*+} e^{-} \bar{\nu}_e$ and $\bar{B}^0 \to D^{*+} \mu^{-} \bar{\nu}_\mu$ using $8.70 \pm 0.09~{\rm fb}^{-1}$ of data collected by the Belle II experiment at the SuperKEKB…

We report a measurement of the inclusive electron energy spectrum for semileptonic decays of B mesons in a 140 fb^-1 data sample collected near the Upsilon(4S) resonance, with the Belle detector at the KEKB asymmetric energy e^+ e^-…

The paper summarizes recent results from the Belle and Belle II collaborations on semileptonic $B$ decays measurements including inclusive and exclusive determination of Cabibbo-Kobayashi-Maskawa matrix elements $|V_{cb}|$ and $|V_{ub}|$…

We report a study of $B \to J/\psi(\ell^{+}\ell^{-})K$ decays, where $\ell$ represents an electron or a muon, using $e^{+}e^{-}$ collisions at the $\Upsilon(4S)$ resonance. The data were collected by the Belle II experiment at the SuperKEKB…