Related papers: Tau Kinematics from Impact Parameters
The vector and scalar form factors relevant to the second-class current $\tau^-\to\pi^-\eta^{(\prime)}\nu_\tau$ processes are evaluated supplementing Chiral Perturbation Theory with the inclusion of resonances as explicit degrees of…
Using the massive helicity formalism we calculate the five-body average square amplitude of the decays $\tau^{-}\to \ell_i^{-} \ell_i^{+} \ell_j^{-} \bar{\nu}_{j} \nu_{\tau}$ $(\ell=e,\,\mu)$ within the Standard Model (SM), we then…
The decays $\tau^-\to K^-\eta\nu_\tau$ and $K^-\eta^\prime\nu_\tau$ are studied in the context of Chiral Perturbation Theory supplemented with the explicit inclusion of resonances. For the required vector-form factors we have explored three…
The electromagnetic and weak dipole moments of the Tau-lepton have been measured by experiments at e+e- colliders. Data samples of e+e- --> tau+tau-, e+e- --> tau+tau- gamma and e+e- --> e+e-tau+tau- events collected at centre-of-mass…
Limits on the anomalous magnetic moment and the electric dipole moment of the $\tau$ lepton are calculated through the reaction $e^{+}e^{-}\to \tau^+ \tau^- \gamma$ at the $Z_1$-pole and in the framework of a left-right symmetric model. The…
We present an approach which allows for modifications of the (minimal) analytic QCD model of Shirkov, Solovtsov et al. The discontinuity function of the (minimal) analytic QCD coupling parameter is changed at the low time-like momenta by a…
We present a search for the decay B+ --> tau+ nu_tau using 467.8 x 10^6 B B-bar pairs collected at the Upsilon(4S) resonance with the BABAR detector at the SLAC PEP-II B-Factory. We select a sample of events with one completely…
We study the disintegration $\tau^- \to \pi^-\ell^+\ell^-\nu_\tau$, where $l$ denotes either an electron or a muon. This process requires knowledge about the $W^*\gamma^*\pi$ interaction, which is modeled using Resonance Chiral Theory.…
By means of the universal unitary and analytic model of electromagnetic structure of hadrons the two-photon decay rates of P=pi^0, eta, eta' mesons are determined in an alternative way from data on their transition form factors.
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…
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…
In this manuscript the B -> pi tau nu decay is investigated in the context of the 2HDM type II extension of the SM. In particular, predictions for the ratio of semileptonic branching fractions from l = tau and l = electron, muon are…
We briefly review electromagnetic radiative corrections in semileptonic tau decays and their main applications.
In a previous paper we have calculated the decay $\tau\to\pi\nu_\tau\gamma$. We used a given relative sign between the internal bremsstrahlung and the structure dependent radiation, which has been used by several other authors before.…
We suggest the study of events in the SuperKamiokande neutrino data due to charged- and neutral-current neutrino reactions followed by weak and/or electromagnetic decays of struck nuclei and fragments thereof. This study could improve the…
The long-distance electromagnetic radiative corrections to tau- -> pi- pi0 nu are re-evaluated. A meson dominance model is used to describe the emission of real photons in this decay. Results obtained for the hadronic spectrum and the decay…
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…
Motivated by the anomalies present in $b \to u$ and $b \to c$ semileptonic decays, we study the corresponding $B_s \to (K,K^*) \tau \nu$ and $B \to \pi \tau \nu$ decays within an effective field theory formalism. Our analysis is based on a…
Predictions for semi-leptonic decay rates of the tau lepton into two and three meson final states with one or two kaons are derived, including a discussion of K_S pi- K_S, K_L pi- K_L and K_S pi- K_L. The hadronic matrix elements are…
The \tau \to \omega,\phi \pi^- \nu_\tau decays of the \tau lepton are studied using the method of phenomenological SU(3) * SU(3) chiral Lagrangians. It is shown that the obtained value for the \tau \to \phi \pi \nu_\tau decay probability is…