Related papers: Beam background expectations for Belle II at Super…
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…
A muon collider represents the ideal machine to reach very high center-of-mass energies and luminosities by colliding elementary particles. This is the result of the low level of beamstrahlung and synchrotron radiation compared to linear or…
The silicon vertex detector (SVD) is installed at the heart of the Belle II experiment, taking data at the high-luminosity $B$-Factory SuperKEKB since 2019. The detector has shown a stable and above-99\% hit efficiency, with a large…
Consideration is being given to upgrading the SuperKEKB e$^+$e$^-$ collider with polarized electron beams, which would open a new program of precision electroweak physics at a centre-of-mass energy of 10.58GeV, the mass of the…
A major LHCb detector upgrade will be installed during long shutdown~4 (LS4) of the CERN Large Hadron Collider. The experiment will operate at a maximum luminosity of up to $1.5\times 10^{34}\mathrm{cm}^{-2}\mathrm{s}^{-1}$, with acceptance…
Using the Belle data on the decay $\Upsilon(10860)\to \Upsilon(1S)f_0(980)\to\Upsilon(1S)\pi^+\pi^-$, we estimate the fraction of the process $\Upsilon(10860)\to\Upsilon(1S)f_0(980)\to \Upsilon(1S)\eta\pi^0$, caused by the mixing of…
The CKM angle $\phi_3$ is less precisely known than the angle $\phi_1$ and the only one that is accessible with tree-level decays in a theoretically clean way. The key method to measure $\phi_3$ is through the interference between $B^+\to…
This is the third out of five chapters of the final report [1] of the Workshop on Physics at HL-LHC, and perspectives on HE-LHC [2]. It is devoted to the study of the potential, in the search for Beyond the Standard Model (BSM) physics, of…
We report a search for lepton-flavor-violating decays $\tau^- \to \ell^- \phi$ ($\ell^- =e^-,\mu^-$) at the Belle II experiment, using a sample of electron-positron data produced at the SuperKEKB collider in 2019-2021 and corresponding to…
Interest in highly-compressed electron beams has been increasing in recent times, driven by the study of non-linear and even non-perturbative aspects of QED [2]. The FACET-II [7] facility at SLAC is currently (at the time of writing) being…
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…
We present the result of a search for the charged-lepton-flavor violating decays $\tau^- \rightarrow e^\mp \ell^\pm \ell^-$, where $\ell$ is a muon or an electron, using a data sample with an integrated luminosity of 428 fb$^{-1}$ recorded…
We present the measurements, performed by the Belle II experiment, related to the B and D meson decays. These results are based on 63 fb$^{-1}$ and 9 fb$^{-1}$ of $e^+e^-$ collision data recorded by the Belle II detector at a center-of-mass…
Accelerator-based searches for dark matter are aiming for high sensitivity and need an experimental setup with high luminosity. This field of research is often called intensity frontier physics. One of the best motivated portals of…
Future collider detectors at muon colliders will be bombarded by Beam-Induced Backgrounds (BIB) due to the in-flight muon decays from the beam line. These backgrounds can inhibit the ability of the detector and subsequent data analysis to…
The BELLE detector has already accumulated e^+ e^- collision data at the KEKB-collider corresponding to 600 fb^-1. BaBar has accumulated data of approximately 390 fb^-1 at PEP-II. Both are running on asymmetric energy e^+ e^- colliders at…
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 present recent results from the Belle II experiment related to quarkonium and charm physics. With data samples collected by Belle II during operation of the SuperKEKB collider above the $\Upsilon(4S)$ resonance, we study the processes…
We present a measurement of the $\tau$-lepton mass using a sample of about 175 million $e^+e^- \to \tau^+\tau^-$ events collected with the Belle II detector at the SuperKEKB $e^+e^-$ collider at a center-of-mass energy of…
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…