Related papers: About The Polarized $\tau$ Lepton Radiative Decay
The pure lepton decay of the polarized muon is considered, accounting for a new tensor interaction which is outside of the Michel local interactions. This interaction leads to new energy distribution and polarization of the final charged…
We carry out the joint study of the semileptonic tau decays into the two-meson and axion-meson channels, viz. $\tau^-\to (P_1P_2)^-\nu_\tau$ and $\tau^-\to \pi^-(K^-) a\nu_\tau$ within the framework of resonance chiral theory by including…
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…
Calculations of transverse polarization of leptons in the decay $W\rightarrow l\nu$ with polarized $W$'s are presented. Planned accelerators will produce enough $W$'s for observation of the Standard Model contributions to this polarization.…
General expressions for the unpolarized differential cross section and for various polarization observables in the coherent pseudoscalar meson photo- and electroproduction on the deuteron target have been obtained in one-photon-exchange…
Structure functions and polarization observables in elastic scattering of longitudinally polarized electron on polarized deuteron are considered within approximation of one-photon + two-photon exchange. It is shown that contribution of…
The branching ratio of the tau lepton to a neutral K meson is measured from a sample of approximately 200,000 tau decays recorded by the OPAL detector at centre-of-mass energies near the Z0 resonance. The measurement is based on two samples…
The polarization density matrix formalism is employed to include the final lepton mass and spin into the popular model by Rein and Sehgal for single pion neutrinoproduction. We investigate the effect of the $\tau$ lepton mass on the…
Tau decays into hadrons have a twofold interest: On the one hand, they are a clean environment for studying the hadronization of the left-handed current of QCD, while, on the other side, provide relevant dynamical information of the…
Many models for physics beyond the Standard Model predict lepton-flavour violating decays of charged leptons at a level which may become observable very soon. We investigate the decays of a Tau-lepton into three charged leptons (Tau ->…
The \tau -> (\omega, \phi)P^-\nu decays, where P^-=\pi^-, K^-, are considered within a phenomenological model with dominance of meson intermediate states. We assume SU(3) flavor symmetry to fix some of the unknown strong interaction…
Secondary radiation of hadrons from a tau pair produced in electron positron collisions may constitute an important obstacle for precision measurements of the production cross section and of branching ratios. The rate for real and virtual…
Analytic expressions are given for the $\tau$ decays into three charged leptons, $\tau\rta \ell\ell\overline \ell\nu_\tau\overline \nu_\ell$, where the $\ell$ are combinations of electrons and muons, and for the radiative decays $\tau\rta…
We study decay distributions in B -> K pi pi gamma, combining contributions from several overlapping resonances in a K pi pi mass range near 1400 MeV, (1^+) K_1(1400), (2^+) K^*_2(1430) and (1^-) K^*(1410). A method is proposed for using…
We present the study of radiative tau decay ($\tau^- \rightarrow \pi^- \nu_\tau \gamma$), computing the structure dependent contribution using Light Cone Sum Rules. This decay includes the same form factors as the radiative pion decay with…
Double-lepton polarization asymmetries in the (B -> l^+ l^- gamma) decay are calculated using the most general, model independent form of the effective Hamiltonian including all possible forms of the interaction. The dependencies of the…
We have determined $R_{\tau/P}\equiv \Gamma(\tau \to P \nu_\tau [\gamma]) / \Gamma(P \to\mu \nu_\mu[\gamma])$ ($P=\pi, K$). Whereas $P$ decays are calculated by using Chiral Perturbation Theory (ChPT), $\tau$ decays have been studied with…
Using chiral low energy theorems and elastic unitarity assumption, the $\tau\to\pi K \nu $ decay is investigated. The vector and scalar $\pi K$ form factors are calculated. It is found that the $\pi K$ spectrum is dominated by the $K^*$…
The branching fractions of radiative leptonic $\tau$ decays $(\tau \to l \nu \bar{\nu} \gamma$, $l=e,\mu)$ were recently measured by the Babar collaboration with a relative error of about 3%. The measurement of the branching ratio…
The photon polarization in radiative decays B -> Y gamma is known to be a subtle probe of the effective Lagrangian structure and possible New Physics effects. We discuss exclusive decay mode B -> phi K gamma where the experimentally…