相关论文: The $\tau\to\nu_\tau\pi e^+e^-$ decay revisited

We analyse the decay $\tau\to\pi\pi\pi\nu$ based on the recently developed techniques to generate axial-vector resonances dynamically. Under the assumption that the a1 is a coupled-channel meson-molecule, the spectral function is described…

We calculate the decay of $\tau^-\to\pi^-\gamma\nu_\tau$ in the framework of Resonance Chiral Theory ($R\chi T$). By demanding the high energy constraints from QCD on the related form factors, we could predict the various physical…

The decay $\tau\to \pi\pi\pi\nu$ is analysed using different methods to account for the resonance structure, which is usually ascribed to the a1. One scenario is based on the recently developed techniques to generate axial-vector resonances…

In this article we analyze the contribution from intermediate spin-0 and spin-2 resonances to the $\tau\to\nu \pi\pi\pi$ decay by means of a chiral invariant Lagrangian incorporating these mesons. In particular, we study the corresponding…

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…

The tau -> pi pi pi nu_tau decay is driven by the hadronization of the axial-vector current. Within the resonance chiral theory, and considering the large-Nc expansion, this process has been studied in Ref.[1]. In the light of later…

$\tau\to\pi\pi\nu$, $\tau\to\pi K\nu$, $\tau\to K\eta\nu$, $\tau\to 3\pi\nu$ and $\tau\to \pi\pi K\nu$ have been investigated using chiral symmetry with dispersion relation in agreement with the unitarity condition.

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.…

The low-energy S-wave component of the decay $D^+ \to K^- \pi^+ \pi^+$ is studied by means of a chiral SU(3)XSU(3) effective theory. As far as the primary vertex is concerned, we allow for the possibility of either direct production of…

K^0 \to pi^- e^+ nu_e e^+ e^- decay is studied up to the next-to-leading order O^4 in chiral perturbation theory. It is found that the O^4 terms appreciably modifiy the shape of the invariant mass distribution of the leptons and the energy…

The potential of performing a combined analysis of the strangeness-changing decays $\tau^{-}\to K_{S}\pi^{-}\nu_{\tau}$ and $\tau^{-}\to K^{-}\eta\nu_{\tau}$ for unveiling the $K^{*}(1410)$ resonance pole parameters is illustrated. Our…

In this paper we document the modifications introduced to the previous version of the Resonance Chiral Lagrangian current ({\it Phys.Rev.} {\bf D86} (2012) 113008) of the $\tau^\pm \to \pi^\pm \pi^\pm \pi^\mp \nu_\tau$ decay which enable…

We re-investigate the radiative charged kaon decay K+- --> pi0 e+- nu_e gamma in chiral perturbation theory, merging the chiral expansion with Low's theorem. We thoroughly analyze the precision of the predicted branching ratio relative to…

We have calculated the O(alpha) radiative corrections to the tau decay tau -> pi (K) nu, taking into account both the point meson contribution and the structure dependent radiation. We find for the ratio Gamma(tau -> pi nu (gamma)) /…

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.…

The polarization effects in the one-meson radiative decay of the polarized $\tau$ lepton, $\tau^-\to\pi^-\gamma\nu_{\tau}$, have been investigated. We present the analytical results for the $t-$distribution of the partial differential…

In a small window of phase space, chiral perturbation theory can be used to make standard model predictions for tau decays into two and three pions. For $\tau \to 2\pi \nu_\tau$, we give the analytical result for the relevant form factor…

Pionic beta decay \pi^+ to \pi^0 e^+ \nu_e is analyzed in chiral perturbation theory with virtual photons and leptons. All electromagnetic corrections up to order e^2 p^2 are taken into account. Theoretical results are confronted with…

Observation of $\tau^-\to\eta^{(\prime)}\pi^-\nu_\tau $ decays at Belle-II would indicate either a manifestation of isospin symmetry breaking or genuine second class currents (SCC) effects. The corresponding radiative…

We present a model-independent analysis of $K^+\to\pi^+\ell^+\ell^-$ and $K_S\to\pi^0\ell^+\ell^-$ decays, including $K\to 3 \pi$ unitarity corrections and a general decomposition of the dispersive amplitude. From the existing data on…