相关论文: Non-standard interactions in $\tau^- \to (\pi^-\et…
Semileptonic decays of $B$ mesons to the tau lepton, despite of experimental difficulties, are of great importance. In particular they are sensitive probes of models with extended Higgs sectors. The results of studies of semitauonic B…
The most general Lorentz invariant spin-correlation functions for $\tau ^{-}\rightarrow \rho ^{-}\nu ,a_1^{-}\nu ,K^{*-}\nu , \pi ^{-}\nu ,K^{-}\nu $ are expressed in terms of eight semi-leptonic parameters. They are physically defined in…
An intriguing opposite sign of the CP violating asymmetry was recently measured in the tau decay modes tau -> Ks pi nutau by the BaBar collaboration, than that expected within the Standard Model. If this result is confirmed with higher…
We study the $\tau^- \to \nu_{\tau} \pi^{-}\pi^{0}\ell^{+}\ell^{-}$ ($\ell=e,\,\mu$) decays, which are $O(\alpha^2)$-suppressed with respect to the dominant di-pion tau decay channel. Both the inner-bremsstrahlung and the structure- (and…
Decays of B mesons to states involving tau leptons can be used as a tool to search for the effects of new physics, such as those involving a charged Higgs boson. The experimental status of the decays B -> tau nu and B -> D^(*) tau nu is…
We study the five-body decays $\mu^- \to e^- e^+ e^- \nu_{\mu} \bar{\nu}_{e}$ and $\tau^- \to \ell^- \ell'^+\ell'^-\nu_{\tau}\bar{\nu}_{\ell}$ for $\ell, \ell'=e, \mu$ within the Standard Model (SM) and in a general effective field theory…
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…
Recent experimental results on exclusive semi-tauonic B meson decays, B -> D(*) tau nu, showing sizable deviations from the standard model prediction, suggest a new physics in which the structure of the relevant weak charged interaction may…
Decays of B mesons into final states containing a tau lepton are sensitive to new charged-current interactions that break lepton-flavor universality. These decays have been studied only at e+e- colliders, where the low-background…
Scalar and tensor interactions were once competitors to the now well-established V-A structure of the Standard Model weak interactions. We revisit these interactions and survey constraints from low-energy probes (neutron, nuclear, and pion…
Exclusive semi-leptonic decays of the tau lepton offer a clean probe to study the hadronization of QCD currents in its non-perturbative regime and learn about resonance dynamics, which drives strong interactions in these processes. In this…
The $\tau$ lepton decays $\tau \to [K^- K^0 \pi^0, K^- K^+ \pi^-, K ^0 \bar{K^0} \pi^-] \nu_{\tau}$ are described in the $U(3) \times U(3)$ NJL quark model. The contact channel and intermediate channels with axial-vector, vector and…
The effect of the interaction of mesons in the final state is additionally considered within the description of $\tau \to \pi \eta(\eta') \nu_{\tau}$ decays. This interaction is taken into account at the level of production of intermediate…
Hadronic $\tau$ decays are studied as probe of new physics. We determine the dependence of several inclusive and exclusive $\tau$ observables on the Wilson coefficients of the low-energy effective theory describing charged-current…
We report results of a search for tau lepton decays strongly suppressed in the Standard Model based on the world-largest data sample accumulated with the Belle detector at the KEKB asymmetric-energy e+e- collider. The decays include: lepton…
In a recent paper, 8 semileptonic parameters were defined to specify the most general Lorentz-invariant spin correlation functions for 2-body tau decays. These parameters can be used to search for anomalous longitudinal-versus transverse…
We study the expected sensitivity at Belle and Belle II for four-body $\tau^\mp \to X^\pm l^\mp l^\mp \nu_{\tau}$ decays where $l=e$ or $\mu$ and $X=\pi$, $K$, $\rho$ and $K^*$ mesons. These decay processes violate the total lepton number…
Given the elusive nature of neutrinos, their self-interaction is particularly difficult to probe. Nevertheless, upper limits on the strength of such an interaction can be set by using data from terrestrial experiments. In this work we focus…
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 have searched for lepton-flavor-violating $\tau$ decays with a pseudoscalar meson ($\eta$, $\eta'$ {and} $\pi^0$) using a data sample of 401 fb$^{-1}$ collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. No…