Related papers: Testing QCD with Hypothetical Tau Leptons
Hadronic decays of the $\tau$ lepton provide a clean environment to study hadron dynamics in an energy regime dominated by resonances, with the interesting information captured in the spectral functions. Recent results from ALEPH on…
This thesis presents a study of the decays $\tau\rightarrow e\nu\overline{\nu}$ identified after a selection of $\tau^+\tau^-$ events produced in $e^+e^-$ collisions at LEP. These collisions, predominantly mediated by a $Z^0$ boson, offer a…
We describe a theoretical approach to compute inclusive widths of heavy hadrons, based on a systematic expansion in the inverse powers of the heavy quark mass. The method reproduces quite well the experimental ratios of $B$ mesons…
The B Factories have generated a large amount of new results on the tau lepton. The present status of some selected topics on tau physics is presented: charged-current universality tests, bounds on lepton-flavour violation, the…
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…
Tau leptons play an important role in the physics program at the LHC. They are used in searches for new phenomena like the Higgs boson or Supersymmetry and in electroweak measurements. Identifying hadronically decaying tau leptons with good…
The status of implementation of new hadronic currents into the Monte Carlo system for simulation of tau-lepton production and decay in high-energy accelerator experiments is reviewed. Since the tau-lepton conference in 2010 substantial…
An intrinsic parity violating hadronic tau lepton decay is investigated. $\tau \to \pi \pi \eta \nu$ is the process in which the dominant contribution to the amplitude is due to the intrinsic parity violation. To predict the hadronic…
The article describes the identification of hadronically decaying tau leptons in ppbar collisions at 1.96 TeV collected by the DZero detector at the Fermilab Tevatron. After a brief description of the motivations and the challenges of…
We study Lepton Flavour Violating hadron decays of the tau lepton within the Simplest Little Higgs model. Namely we consider $\tau \rightarrow \mu (P, V, PP)$ where $P$ and $V$ are short for a pseudoscalar and a vector meson. We find that,…
We analyze the sensitivity of hadronic tau decays to non-standard interactions within the model-independent framework of the Standard Model Effective Field Theory (SMEFT). Both exclusive and inclusive decays are studied, using the latest…
ALEPH/OPAL data on the V-A spectral functions from hadronic tau decays are used in connection with a set of Laplace transform sum rules (LSR) for fixing the size of the QCD vacuum condensates up to dimension 18. Our results favour the ones…
The generalized Crewther relation relates the cross section ratio $R=\sigma(e^+e^- \to {\rm hadrons})/\sigma(e^+e^- \to {\mu}^+ {\mu}^-)$ in $e^+e^-$ annihilation with the Bjorken sum rule or the Gross-Llewellyn Smith sum rule in deep…
tau -> (3 pions) nu_tau decays are analysed within the framework of the resonance effective theory of QCD. We work out the relevant Lagrangian that describes the axial-vector current hadronization contributing to these processes, in…
Many theoretical models, like the Standard Model or SUSY at large tan(beta), predict Higgs bosons or new particles which decay more abundantly to final states including tau leptons than to other leptons. At the energy scale of the LHC, the…
Hadronic decays of the $\tau$ lepton provide a clean environment to study hadron dynamics in an energy regime dominated by resonances. The interesting information is captured in the spectral functions. Recent results from ALEPH on exclusive…
The usage of polarimetry and spin-correlation tests to determine the {\em complete Lorentz structure} of the tau lepton's charged and neutral-current couplings is reviewed. The emphasis is on tests for ``something'' in a $(V-A) + $…
Hyperon decays present a promising alternative for extracting $\vert V_{us} \vert$ from lattice QCD combined with experimental measurements. Currently $\vert V_{us} \vert$ is determined from the kaon decay widths and a lattice calculation…
The semileptonic decay channel B -> D tau nu is sensitive to the presence of a scalar current, such as that mediated by a charged-Higgs boson. Recently the BaBar experiment reported the first observation of the exclusive semileptonic decay…
After overviewing the general features of semileptonic decays of the tau lepton, I will recall the most widely used model for them, namely that of Kuhn-Santamaria (KS), and I will explain the subsequent works that were done along these…