相关论文: $\tau$ lepton mass measurement at Belle II

Using the ARGUS detector at the e+e- storage ring DORIS II, we have searched for the real and imaginary part of the electric dipole formfactor d_tau of the tau lepton in the production of tau pairs at q^2=100 GeV^2. This is the first direct…

We present measurements of the first to fourth moments of the lepton mass squared $q^2$ of \mbox{$B \to X_c \, \ell\, \bar \nu_{\ell}$} decays for $\ell = e, \mu$ and with $X_c$ a hadronic system containing a charm quark. These results use…

$\tau$ 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…

Motivated by models proposed to explain the Standard Model anomalies, and the unprecedented $\tau^{+}\tau^{-}$ data to be collected by the Belle~II experiment during the next years, we study the kinematics of tau pair decays and propose a…

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 $e^+e^-$…

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…

Tau lepton as one of three elementary leptons in nature, the measurement of its mass has ever been performed since its discovery. The present relative accuracy is already at the level of better than 10 to minus 4 and more effects are still…

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…

The anomalous magnetic moment of the tau lepton, a_tau = (g_tau - 2)/2, is a sensitive probe of new physics but is extremely difficult to measure precisely in contrast to electron and muon moments. The best experimental limits were set by…

The large number of $\tau$ leptons available at the Belle II experiment makes it possible to study their properties and the extent of their compositeness. Our strategy relies on three observables defined in terms of elements of the…

We propose a new method to probe the magnetic and electric dipole moments of the $\tau$ lepton using precise measurements of the differential rates of radiative leptonic $\tau$ decays at high-luminosity $B$ factories. Possible deviations of…

We present the results of a search for charged-lepton-flavor violating decays $\tau^{-} \rightarrow \ell^{-}K_{S}^{0}$, where $\ell^{-}$ is either an electron or a muon. We combine $e^+e^-$ data samples recorded by the Belle II experiment…

Recently, the Belle collaboration reported the first measurements of the $\tau^- \to\nu_{\tau}\pi^-e^+e^-$ branching fraction and the spectrum of the pion-dielectron system. In an analysis previous to Belle's results, we evaluated this…

This paper describes a measurement of the Michel parameters, \eta, \rho, \xi, \xi\delta, and the average \nu_{\tau} helicity, h_{\nu_{\tau}}, in tau lepton decays together with the first measurement of the tensor coupling in the weak…

We present the first measurements of branching fractions of rare tau-lepton decays, $\tau^- \rightarrow \pi^- \nu_{\tau} \ell^+ \ell^-$ ($\ell = e$ or $\mu$), using a data sample corresponding to 562 fb$^{-1}$ collected at a center-of-mass…

With the full data sample of $772 \times 10^6$ $B{\bar B}$ pairs recorded by the Belle detector at the KEKB electron-positron collider, the decay $\bar{B} \rightarrow D^* \tau^- \bar{\nu}_\tau$ is studied with the hadronic $\tau$ decays…

The ratio between the B$_\mathrm{c}^+$ $\to$ J/$\psi$$\tau^+\nu_\tau$ and B$_\mathrm{c}^+$ $\to$ J/$\psi$$\mu^+\nu_\mu$ branching fractions is measured using a data sample of proton-proton collisions collected by CMS at a center-of-mass…

We report a measurement of the electric dipole moment of the $\tau$ lepton ($d_\tau$) using an 833~fb$^{-1}$ data sample collected near the $\Upsilon(4S)$ resonance, with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider.…

A comprehensive review of the measurements of $\tau$ lepton mass and $R$ values in the energy region between $2-5$ GeV, achieved at the BES experiment, is presented. In addition to the evaluation of their impact on the test of Standard…

Using the ARGUS detector at the $e^+ e^-$ storage ring DORIS II, we have measured the Michel parameters $\rho$, $\xi$, and $\xi\delta$ for $\tau^{\pm}\to l^{\pm} \nu\bar\nu$ decays in $\tau$-pair events produced at center of mass energies…