相关论文: Tests for Tau's Charged-Current Structure

This is the report of the Intensity Frontier Charged Lepton Working Group of the 2013 Community Summer Study "Snowmass on the Mississippi", summarizing the current status and future experimental opportunities in muon and tau lepton studies…

Within our present knowledge, the tau is the heaviest lepton and the only one decaying into hadrons, a fact that makes it the source of a very rich phenomenology. It represents the third family of leptons in the Standard Model, a feature…

The possibilities to measure lepton forward--backward asymmetries at the LHC in the reaction pp(qqbar) --> l+l- are studied for dilepton events with masses above 400 GeV. It is shown that such measurements allow accurate tests of the…

We perform a complete simulation of the process $ e^+ e^- \to \tau^+ \tau^- \nu \bar{\nu}$, where $\nu$ can be an electron, muon or tau neutrino, in the context of a general Higgs coupling to $\tau$ leptons. We analyse various kinematical…

This study investigates the influence of the fourth generation quarks on the double lepton polarizations in \Lambda_b --> \Lambda \ell^+ \ell^- decay by taking |V^\ast_{t's}V_{t'b}|= 0.005,0.01,0.02,0.03 with phase…

In semi-leptonic $B$ decays with a tau lepton, features of the production process are imprinted on the tau helicity states. Since the tau momentum cannot be fully reconstructed experimentally, the available information on the tau properties…

The process of top-quark pair production followed by semileptonic decays at future high-energy e^+e^- linear colliders is investigated as a possible test of physics beyond the Standard Model. Assuming the most general non-standard forms for…

The Standard Model (SM) predicts the universality of lepton couplings with the electroweak gauge bosons. Semileptonic decays of $b$-hadrons provide a powerful framework for testing the SM and probing possible New Physics effects. In…

We present a search for the lepton flavor violating decay B+ --> K+ tau-/+ mu+/- using 383 million B Bbar events collected by the BABAR experiment. The branching fraction for this decay can be substantially enhanced in new physics models.…

We present recent developments in the diagnostic study of heavy gauge bosons at future $pp$ (CERN LHC) and $e^+e^-$ (NLC) colliders with the emphasis on the model independent determination of gauge couplings of $Z'$ to quarks and leptons.…

Semileptonic decays of polarized $\tau$ leptons are investigated. The most general angular distribution of three meson final states ($\tau\rightarrow \pi\pi\nu,\,K\pi\nu,\, \pi\pi\pi\nu,\\ \,K\pi\pi\nu,\, KK\pi\nu,\, KKK\nu,\,…

Using 467 $fb^{-1}$ of $e^+e^-$ annihilation data collected with the BaBar detector, we measure $\frac{{\cal{B}}(\tau^- \to \mu^- \bar{\nu}_\mu \nu_\tau)}{{\cal{B}}(\tau^- \to e^- \bar{\nu}_e \nu_\tau)} = (0.9796 \pm 0.0016 \pm 0.0036)$,…

We present a comprehensive investigation into the anomalous magnetic dipole moment ($a_\tau$) and electric dipole moment ($d_\tau$) of the $\tau$ lepton using the $\gamma\gamma \to \tau^+\tau^-$ process at future lepton colliders, with the…

We study the phenomenology of the \tau^- \to \pi^- \nu_\tau \ell^+ \ell^- decays (\ell = e, \mu), predicting the respective branching ratios and di-lepton invariant-mass spectra. In addition to the model-independent (QED) contributions, we…

We have searched for decays of the tau lepton into seven or more charged particles, using data collected with the OPAL detector from 1990 to 1995 in e^+e^- collisions at sqrt(s) ~ M_Z. No candidate events were found and an upper limit on…

We benefit from a recent lattice determination of the full set of vector, axial and tensor form factors for the $\Lambda_b\to \Lambda^*_c(2595)\tau\bar\nu_\tau$ and $\Lambda^*_c(2625)\tau\bar\nu_\tau$ semileptonic decays to study the…

Recent results on tau physics from BaBar are reviewed. Limits on lepton-flavor violation in the tau decay process tau->lll are presented based on 91.6 fb^1 of data. In all six decay modes considered, the numbers of events found in data are…

We study potential New Physics effects in the $\bar B \to D^{(*)} \tau \bar\nu$ decays. As a particular example of New Physics models we consider the class of leptoquark models and put the constraints on the leptoquark couplings using the…

Various precision determinations of the Fermi constant are compared. Included are muon and (leptonic) tau decays as well as indirect prescriptions employing $\alpha, m_Z, m_W, \ssthwmzms, \Gamma(Z\to\ell^+\ell^-)$, and $\Gamma(Z \to \nu\bar…

Strong interactions between electrons in two dimensions can realize phases where their spins and charges separate. We capture this phenomenon within a dual formulation. Focusing on square lattices, we analyze the long-wavelength structure…