Related papers: Prospects for $\tau$ Lepton Physics at Belle II
Motivated by flavour symmetry models, we construct theories based on a low-energy limit featuring lepton flavour triality that have the flavour-violating decays $\tau^\pm \to \mu^\pm \mu^\pm e^\mp$ and $\tau^\pm \to e^\pm e^\pm \mu^\mp$ as…
We present a search for lepton-flavor-violating tau decays into three leptons (electrons or muons) using 782 fb^-1 of data collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. No evidence for these decays is…
$\tau$ is playing an important role in the current B-physics indications from experiments of lepton flavor universality violations(LFUV). This suggests it be given increasing attention theoretically in the coming years, given also the fact…
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…
High-precision flavor physics measurements play a complementary role to the direct searches for new physics by CMS and ATLAS experiments at LHC. Such measurements will be performed with the Belle II detector at the upgraded KEKB accelerator…
We report a search for the lepton-flavor-violating decays $\tau^{\pm}\to\ell^{\pm}\alpha$~($\ell=e,\mu$), where $\alpha$ is an undetected spin-0 particle, such as an axion-like particle using $736\times10^{6}$ tau lepton pairs collected by…
The paper discusses new method for electron/pion and muon/pion separation in the Belle II detector at transverse momenta below 0.7 $\mathrm{GeV}/c$, which is essential for efficient measurements of semi-leptonic decays of $B$ mesons with…
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…
In 2024, the Belle II experiment resumed data taking after the Long Shutdown 1, which was required to install a two-layer pixel detector and upgrade accelerator components. We describe the challenges of this shutdown and the operational…
The MEG II experiment searches for the Charged Lepton Flavour Violating (CLFV) decay $\mu\rightarrow e \gamma$. This decay is foreseen by the Standard Model (SM) of Particle Physics at non observable rates through neutrino oscillation.…
The Belle II detector is currently under construction at the SuperKEKB electron-positron high-luminosity collider, that will provide an instantaneous luminosity 40 times higher than that of KEKB. There- fore the Belle-II VerteX Detector…
We consider the lepton number violating decays $B \to \mu^{\pm} \mu^{\pm} \pi^{\mp}$ and $B \to D^{(*)} \mu^{\pm} \mu^{\pm} \pi^{\mp}$ which may be detected at LHCb and Belle-II experiments; and $B \to \mu^{\pm} \mu^{\pm} e^{\mp} \nu$ and…
We have searched for neutrinoless $\tau$ lepton decays into $\ell$ and $V^0$, where $\ell$ stands for an electron or muon, and $V^0$ for a vector meson ($\phi$, $\omega$, $K^{*0}$ or $\bar{K}^{*0}$), using 543 fb$^{-1}$ of data collected…
We have searched for lepton flavor violating semileptonic tau decays using a data sample of 153.8/fb accumulated with the Belle detector at the KEKB e+e- collider. For the six decay modes studied, the observed yield is compatible with the…
The Belle experiment has given a substantial contribution in the field of heavy quarkonia. Several new states were announced by Belle for the first time, in both charmonium and bottomonium spectrum, or the confirmation from Belle…
We search for lepton-flavor-violating tau-> ell V^0 decays, where ell is an electron or muon and V^0 is one of the vector mesons rho^0, phi, omega, K*0 and K*0-bar. We use 854 fb^{-1} of data collected with the Belle detector at the KEKB…
We have searched for neutrinoless $\tau$ lepton decays into $\ell$ and $V^0$, where $\ell$ stands for an electron or muon, and $V^0$ for a vector meson ($\phi$, $\omega$, $K^{*0}$, $\bar{K}^{*0}$ or $\rho^0$), using 543 fb$^{-1}$ of data…
We report on a search for a heavy neutrino in the decays $\tau^- \to \pi^- \nu_h$, $\nu_h \to \pi^\pm \ell-+$, $\ell = e, \mu$. The results are obtained using the full data sample collected with the Belle detector at the KEKB asymmetric…
We have searched for the lepton flavor violating decays $\tau^-\to \ell^-\ks$ ($\ell = e {or} \mu$), using a data sample of 281 fb$^{-1}$ collected with the Belle detector at the KEKB $e^+e^-$ asymmetric-energy collider. No evidence for a…
We report on the construction, operation, and performance of the Time-of-Propagation detector with imaging used for the Belle II experiment running at the Super-KEKB $e^+e^-$ collider. This detector is located in the central barrel region…