Related papers: Three generations mixing and the $\tau$ decay puzz…
The leptonic decays of the tau lepton provide relevant tests on the structure of the weak currents and the universality of their couplings to the gauge bosons. The hadronic tau decay modes constitute an ideal tool for studying low--energy…
We discuss the phenomenology of third generation sfermions paying particular attention to the implications of the Yukawa couplings and to the left-right mixing. Analytical formulae are given for the sfermion mixing, the production cross…
Recent studies of novel four-body lepton number violating decays of $\tau$ leptons and neutral $B$ mesons are summarized and updated. These decays are assumed to be enhanced by the exchange of resonant Majorana neutrinos. It is shown that…
It has been recently proposed that neutrino mass could originate from Yukawa interactions of leptons with new colored particles. This raises the interesting possibility of testing mass generation through copious production of those…
The pure leptonic or semileptonic character of tau decays makes them a good laboratory to test the structure of the weak currents and the universality of their couplings to the gauge bosons. The hadronic tau decay modes constitute an ideal…
The Standard Model predicts that the electroweak couplings to the three charged leptons are identical. However, in the last decade, experimental measurements have suggested that semileptonic processes involving taus could have a slightly…
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. In the present paper we investigate the decays of a Tau into three charged…
I outline recent results using CLEO3 data involving the decay of the tau to three charged hadrons and a neutrino, as well as an investigation of the structure of the decay tau to KKpinu and the Wess-Zumino term in this decay.
In this work the following lepton flavor violating $\tau$ and $\mu$ decays are studied: $\tau^- \to \mu^- \mu^- \mu^+$, $\tau^- \to e^- e^- e^+$, $\mu^- \to e^- e^- e^+$, $\tau^- \to \mu^- \gamma$, $\tau^- \to e^- \gamma$ and $\mu^- \to e^-…
We present two topics on charm meson semileptonic decay. Evidence for interference in the decay K*munu and new results on the D+ to K*munu/K2pi branching fraction.
We study two and three meson decays of the tau lepton within the framework of the Resonance Chiral Theory, that is based on the following properties of QCD: its chiral symmetry in the massless case, its large-N_C limit, and the asymptotic…
Anomalies in semi-leptonic $B$ decays could indicate new physics beyond the standard model(SM). There is an older puzzle in non-leptonic $B \to \pi K$ decays. The new particles, leptoquarks and diquarks, required to solve the semi-leptonic…
We discuss proton and neutron decays involving three leptons in the final state. Some of these modes could constitute the dominant decay channel because they conserve lepton-flavor symmetries that are broken in all usually considered…
$\tau$ leptons emitted in cascade decays of supersymmetric particles are polarized. The polarization may be exploited to determine spin and mixing properties of the neutralinos and stau particles involved.
Recent reports of the observation of the decay $\tau \rarrow \nu_{\tau} + K + \pi + \pi$ raise interesting questions. The $u-s$ quark mass difference can induce an effective second-class current in the strange sector and enhance decays to…
In a recent paper, we showed that tree level up-down unification of fermion Yukawa couplings is a natural consequence of a large class of supersymmetric models. They can lead to viable quark masses and mixings for moderately large values of…
The impact of the new tau decay data on the various $\tau$ puzzles and on the possibility of approximate supersymmetry is discussed. The most economical solution of the problems in $\tau$ decay and that favored by recent new data supports…
By introducing a set of new triplet leptons (with nonzero hypercharge) that can Yukawa couple to their Standard Model counterparts, new sources of tree-level flavor changing currents are induced via mixing. In this work, we study some of…
We re-examine the problem of simultaneously describing in a consistent way all radiative and leptonic decays of light mesons (V -> P gamma, P -> V gamma, P -> gamma gamma, V -> e^+ e^-). For this purpose, we rely on the Hidden Local…
We propose a model in which the Yukawa couplings of Higgs doublets are related to the couplings of the chiral fermions to a scalar leptoquark triplet. This is due to their common origin via mixing with a vector-like family distinguished by…