相关论文: The Belle II Experiment and SuperKEKB Upgrade

We present measurements of $B \to K{}^{*}(892)\gamma$ decays using $365\,{\rm fb}^{-1}$ of data collected from 2019 to 2022 by the Belle~II experiment at the SuperKEKB asymmetric-energy $e^+e^-$ collider. The data sample contains $(387 \pm…

The Belle-II experiment is expected to collect large data samples at the $\Upsilon(4S)$ and $\Upsilon(5S)$ resonances to study primarily $B$ and $B_s$ mesons. We discuss what other data above the $B\bar{B}$ threshold are of interest. We…

In this paper, we briefly review results on rare decays of $B$ mesons from the Belle experiment, based on 10.4 fb$^{-1}$ data collected on the $\Upsilon$(4S) resonance. The topics include measurements of Cabibbo suppressed decays $B \to…

This letter presents a search for the rare flavor-changing neutral current process $B^{0}\rightarrow K^{\ast 0}\tau^{+}\tau^{-}$ using data taken with the Belle detector at the KEKB asymmetric energy $e^{+}e^{-}$ collider. The analysis is…

This paper reports a study of $B \to K^{*}\gamma$ decays using $62.8\pm 0.6$ fb$^{-1}$ of data collected during 2019--2020 by the Belle II experiment at the SuperKEKB $e^{+}e^{-}$ asymmetric-energy collider, corresponding to $(68.2 \pm 0.8)…

Results on two inclusive Vub measurements at Belle are presented. We also present a new measurement of the branching fraction for Ds->phi pi. A data sample of 78.1fb^-1 accumulated using the Belle detector at the KEKB asymmetric e^+e^-…

The Belle II experiment at KEK in Japan considers upgrading its vertex detector system to address the challenges posed by high background levels caused by the increased luminosity of the SuperKEKB collider. One proposal for upgrading the…

New results of the Belle experiment at the KEKB asymmetric e^+e^- collider are presented, in particular (a) measurement of the mass and width of the $\eta_c$ and $\eta_c'$ in B meson decays, (b) measurement of the mass, width and quantum…

We have analyzed 121.4 fb$^{-1}$ of data collected at the $\Upsilon(5S)$ resonance by the Belle experiment using the KEKB asymmetric-energy $e^+e^-$ collider to search for the decay $B_s^0\to J/\psi\pi^0$. We observe no signal and report an…

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

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 search for $B^{0}$ decays into invisible final states using a data sample of $657 \times 10^{6}$ $B\bar{B}$ pairs collected at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB $e^{+}e^{-}$ collider. The signal is…

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…

The high design luminosity of the SuperKEKB electron-positron collider will result in challenging levels of beam-induced backgro\ unds in the interaction region. Understanding and mitigating these backgrounds is critical to the success of…

The Belle-II experiment and superKEKB accelerator will form a next generation B-factory at KEK, capable of running at an instantaneous luminosity 40 times higher than the Belle detector and KEKB. This will allow for the elucidation of many…

Upgrading the SuperKEKB electron-positron collider with polarized electron beams opens a new program of precision physics at a center-of-mass energy of 10.58 GeV. This white paper describes the physics potential of this `Chiral Belle'…

Recent results of baryonic B decays from Belle are reported. This study is done by a 78 fb$^{-1}$ data sample, consisting of $85.0 \pm 0.5$ million $B\bar{B}$ pairs, collected by the Belle detector at the KEKB asymmetric energy $e^+e^-$…

We report on a new search for two-body baryonic decays of the B meson. Improved sensitivity compared to previous Belle results is obtained from 414 fb^-1 of data that corresponds to 449 million B B-bar pairs, which were taken on the…

Precision studies of flavour-changing processes involving quarks and leptons provide a number of ways to improve knowledge of the Standard Model and search for physics beyond it. There are excellent short- and mid-term prospects for…

The HyperCP experiment reported the observation of three events for the $\Sigma^+ \rightarrow p \mu^+\mu^-$ decay. The dimuon masses of the observed events are clustered within the detector resolution of 1 MeV/$c^2$. These decays might be…