Related papers: Tests for Tau's Charged-Current Structure
The conditions for the independence of decays of the spin-1/2 resonances on the production mechanism of the resonances and on polarizations of the incoming and outgoing particles are derived and applied in the case of several tau-lepton…
This is a review of some of the highlights of the 6th workshop on the physics of the tau lepton and its neutrino. This includes the test of lepton universality, measurement of Lorentz Structure, study of hadronic decays, direct evidence of…
The neutrinos produced in $\tau$ decays cannot be directly detected, making the reconstruction of $\tau$ kinematics challenging and affecting measurements of quantum correlations such as spin entanglement. For the process $e^+e^- \to…
A search for lepton-flavor and lepton-number violation in the decay of the tau lepton into one charged lepton and two charged hadrons is performed using 221.4 $\mathrm{fb}^{-1}$ of data collected at an $e^+e^-$ center-of-mass energy of…
Charged-lepton-flavor-violation is predicted in several new physics scenarios. We update the analysis of $\tau$ lepton decays into a light charged lepton ($\ell$ = $e^{\pm}$ or $\mu^{\pm}$) and a vector meson ($V^0$ = $\rho^0$, $\phi$,…
The anomalous magnetic moment of the tau lepton $a_\tau = (g_\tau -2)/2$ strikingly evades measurement, but is highly sensitive to new physics such as compositeness or supersymmetry. We propose using ultraperipheral heavy ion collisions at…
Current and upcoming experiments should improve the sensitivity to radiative lepton decays by an order of magnitude. This paper assumes that one of the tau --> (e, mu) gamma decays is observed, and explores the structure and consequences of…
We point out that the cross-section for the process $e^+ e^- \to e^+ e^- \tau^+ \tau^-$ at LEP is large enough to allow for a study of the anomalous electromagnetic couplings of the $\tau$ lepton. We show that the present bounds on the…
Recent theoretical results in tau lepton physics and their implications for the experimental analysis are presented. The paper is split into the following chapters: 1. Introduction, 2. Weak Couplings, 3. Inclusive Decays, Perturbative QCD…
Three important QCD-related aspects of the $\tau$ and $\mu$ dynamics are reviewed: the determination of the strong coupling from the hadronic tau decay width, leading to the updated value $\alpha_s(m_\tau^2) = 0.331 \pm 0.013$; the…
We analyze the possibility of testing local Lorentz invariance from the observation of tau decays. Future prospects of probing distances below the electroweak characteristic scale are discussed.
We use experimental data on $e^+e^- \to \eta (\eta^{\prime})\pi^+\pi^-$ and conservation of vector current to estimate the branching fractions of $\tau^-$ decay to $\eta (\eta^{\prime})\pi^-\pi^0\nu_{\tau}$. The obtained values are compared…
The evaluation, systematic analysis and numerical study of the semileptonic $\tau$-lepton decays with two mesons in the final state has been made in the frame of the standard model extended by right handed neutrinos. In the analysis,…
We examine in detail the semi-leptonic decay $\Lambda_b \to \Lambda_c \tau{\bar \nu}_{\tau}$, which may confirm previous hints, from the analogous $B$ decay, of a new physics beyond the standard model. First of all, starting from rather…
A search for the decay of the tau lepton to five charged and two neutral pions is performed using data collected by the BABAR detector at the PEP-II asymmetric-energy e+e- collider. The analysis uses 232 fb-1 of data at center-of-mass…
We report some new results on tau decays obtained by the BaBar collaboration using 468 inverse femtobarn of electron-positron collisions recorded at the PEP-II asymmetric collider at Stanford Linear Accelerator Center. First We will show…
Angular-energy distributions are studied for charged leptons and neutrinos from the decays of polarised top quarks. A small admixture of V+A interactions is incorporated. The polarisation dependent part of the neutrino distribution which…
Minimal extensions of the Standard Model that are motivated by grand unified theories or superstring models with an E_6 symmetry can naturally predict heavy neutrinos of Dirac or Majorana nature. Such heavy neutral leptons violate the de-…
We test whether or not the tau lepton manifests the same couplings as the mu lepton by investigating the relative decay rates in purely leptonic D+ meson decays. Specifically, we place the first upper limit on the ratio R=Gamma(D+ -> tau+…
Tau-lepton decays with up to two $\pi^0$'s in the final state, $\tau^+ \to \pi^+ \bar{\nu}_\tau$, $\rho^+ (\pi^+\pi^0) \bar{\nu}_\tau$, $a^+_1 (\pi^+\pi^0\pi^0) \bar{\nu}_\tau$, are used to study the performance of the barrel part of the…