相关论文: Prospects for Rare Decays at Belle II

We report expected sensitivities for the measurement of the three angles of the Unitarity Triangle in B meson decays using 50 ab-1 of electron-positron collisions recorded by the Belle II detector at the SuperKEKB collider at KEK, Japan.

The Belle detector operated at KEKb B-factory in 1999-2010 was one of the most remarkable experiments in the field of elementary particle physics of the last decades. The Belle successor, Belle II collaboration, is aimed to operate the…

We will present a review of the most interesting results on rare B decays from the B Factories, based on the data collected by the BaBar and Belle detectors at asymmetric $e^+ e^-$ colliders at the center of mass energy of the…

We report a measurement of the $D^0$ and $D^+$ lifetimes using $D^0\to K^-\pi^+$ and $D^+\to K^-\pi^+\pi^+$ decays reconstructed in $e^+e^-\to c\bar{c}$ data recorded by the Belle II experiment at the SuperKEKB asymmetric-energy $e^+e^-$…

With the first data being recorded at Belle II, we are at the brink of a new era in quark flavour physics. The many exciting new opportunities for Belle~II include a full angular analysis of inclusive ${\bar B \to X_{s} \, \ell^+\ell^-}$…

We report a measurement of the branching fraction of $B \to K^{\ast}(892)\ell^+\ell^-$ decays, where $\ell^+\ell^- = \mu^+\mu^-$ or $e^+e^-$, using electron-positron collisions recorded at an energy at or near the $\Upsilon(4S)$ mass and…

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 Belle and Belle II experiments have collected a 1.3 ab$^{-1}$ sample of $e^+e^-\to B\bar B$ collisions at $\Upsilon(4S)$ centre-of-mass energy. This is ideal environment to search for rare electroweak penguin $B$ decays and notably…

Belle II measurement of the branching fraction for $B^{+} \to K^{+} \nu \bar{\nu}$ shows a $2.7\sigma$ excess over the Standard Model prediction and motivates new-physics explanations such as axion-like particles, Higgs-like scalars, or…

Understanding the nature of dark matter is one of the most exciting challenges in fundamental physics nowadays, requiring the synergy of different search techniques, as well as theoretical inputs. An interesting opportunity for the…

We present preliminary results on the reconstruction of the $B^0\to J\mskip 1mu / \psi\mskip 2mu K^0_{\scriptscriptstyle L}$ decay, where $J\mskip 1mu / \psi\mskip 2mu\to\mu^+\mu^-$ or $e^+e^-$. Using a dataset corresponding to a luminosity…

A search for the flavor-changing neutral-current decay $B^{+}\to K^{+}\nu\bar{\nu}$ is performed at the Belle II experiment at the SuperKEKB asymmetric energy electron-positron collider. The results are based on a data sample corresponding…

We report on measurements of branching fractions ($\mathcal{B}$) and CP-violating charge asymmetries ($\mathcal{A}_{\rm CP}$) of multibody charmless $B$ decays reconstructed by the Belle II experiment at the SuperKEKB electron-positron…

Upgrades at the Belle II experiment and the SuperKEKB asymmetric-energy electron-positron collider enable precise measurements of particle decays. Even with early data, Belle II has made several world-leading measurements of particle…

We report on a Belle II measurement of the branching fraction ($\mathcal{B}$), longitudinal polarization fraction ($f_L$), and CP asymmetry ($\mathcal{A}_{CP}$) of $B^+\to \rho^+\rho^0$ decays. We reconstruct $B^+\to \rho^+(\to…

The $b \rightarrow s \gamma$, $b \rightarrow d \gamma$ and $b \rightarrow s \ell^+ \ell^-$ processes are allowed at higher order via the electroweak loop or box diagrams in the Standard model. It is sensitive probe to search for new physics…

The Belle~II experiment is designed to search for physics beyond the Standard Model by investigating rare decays at the SuperKEKB \(e^{+}e^{-}\) collider. Owing to the significant beam background at high luminosity, the data acquisition…

We search for the rare radiative decay $D^0\to\gamma\gamma$ using a data sample with an integrated luminosity of $832{\rm fb^{-1}}$ recorded by the Belle detector at the KEKB $e^+e^-$ asymmetric-energy collider. We find no statistically…

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…

We report a search for the rare decays B -> h(*) nu nubar, where h(*) stands for K+, Ks0, K*+, K*0, pi+, pi0, rho+, rho0 and phi. The results are obtained from a 711 fb-1 data sample that contains 772 million BB pairs collected at the Y(4S)…