相关论文: The Long Distance Contribution to $D\to\pi l^+l^-$

The decay $B^- \to K^- K^- \pi^+$ has been sugested as a test for minimal supersymmetric standard model and for supersymmetric models with R-parity violating couplings, in view of its extreme smallnesss in the standard model. We calculate…

The long-distance contribution via the two-photon intermediate state to the forward-backward asymmetries in decays K+ --> pi+ l+ l- (l=e and mu) has been studied within the standard model. In order to evaluate the dispersive part of the K+…

The semileptonic decay $D^{+}_{s}\rightarrow \pi^{+}\ell^{-}\ell^{+}$, where $\ell=e, \ \mu$, is used as a reference channel when looking for suppressed or forbidden processes of the standard model of the form $D_{s}\rightarrow…

In this work we study the radiative leptonic decays of $B^-$, $D^-$ and $D_s^-\to \gamma l \bar{\nu}$, including both the short-distance and long-distance contributions. The short-distance contribution is calculated by using the…

We evaluate the model-dependent piece of O(alpha) long-distance radiative corrections to tau^- \to \pi^- \pi^0\nu_{\tau} decays by using a meson dominance model. We find that these corrections to the di-pion invariant mass spectrum are…

We calculate long distance contributions to $K\to\pi\nu\bar{\nu}\,,\ \pi\pi\nu\bar{\nu}$, and $\pi\pi\pi\nu\bar{\nu}$ modes within the framework of chiral perturbation theory. We find that these contributions to decay rates of $K\to…

We estimate the long distance contribution to the $K^+ \rightarrow \pi^+ \nu \bar\nu$ decay amplitude using chiral perturbation theory. We find that it is likely to be less than a few percent of the part of the short distance contribution…

The interplay between short- and long-distance contributions to the K_L-->mu+ mu- decay amplitude is analyzed. The long-distance piece is estimated using chiral perturbation theory techniques and large-N_C considerations, leading to a…

We estimate the long distance (LD) contribution to the magnetic part of the $s \to d\gamma$ transition using the Vector Meson Dominance approximation $(V=\rho,\omega,\psi_i)$. We find that this contribution may be significantly larger than…

We investigate the mechanism of K+ -> pi+ l+ l- (l= e, mu) decays in which a virtual photon is emitted either from the incoming K+ or the outgoing pi+. We point out some inconsistencies with and between two previous calculations, discuss…

In this paper we consider the decay $D^+\to\pi^+\ell^+\ell^-$, addressing in particular the resonance contributions as well as the relatively large contributions from the weak annihilation diagrams. For the weak annihilation diagrams we…

We calculate the branching ratio of the non-resonant $B \to D^- \pi^+\pi^+\pi^- $ decay using a simple model based on the framework of the factorization approach. In naive factorization approach, there are only tow tree diagrams for this…

In this work, we study the resonance contributions to the decay $B^-\to K^+K^-\pi^-$, which is dominated by the scalar $f_0(980), K_0^*(1430)$, vector $\rho(1450), \phi(1020), K^*(892)$ and tensor $f_2(1270)$ resonances. The three-body…

The short-distance contribution due to the $c\to u\gamma$ penguin as well as long-distance contributions are considered in an analysis of $D\to V\gamma$ decays, the latter being dominant. The matrix elements for nine $D\to V\gamma$…

The decays of the $B^{+}$ meson to the final state $D^{*-}D^{+}_{s}\pi^{+}$ are studied in proton-proton collision data collected with the LHCb detector at centre-of-mass energies of 7, 8, and 13 TeV, corresponding to a total integrated…

We analyse the long-distance contribution to $B\to X_s\ell^+\ell^-$ differential decay rate when the momentum dependence of $\psi$ and $\psi'$-$\gamma$ conversion strength is taken into account. The results indicate that the resonance to…

This talk gives a short summary of some work \cite{FGEdeR04} realized in collaboration with E. de Rafael and concerning $K\ra\pi \ell^+ \ell^-$ decays, in a combined framework of Chiral Perturbation Theory and Large--$N\_c$ QCD under the…

We re-analyse the long distance contributions to the process $b \to s l^+ l^-$. Full $q^2$-behavior of the vector meson dominance amplitude is used together with the effect of Terasaki suppression, and comparisons with the previous results…

A measurement of the phase difference between the short- and long-distance contributions to the $B^{+}\to K^{+}\mu^{+}\mu^{-}$ decay is performed by analysing the dimuon mass distribution. The analysis is based on $pp$ collision data…

Neutrinoless double beta decay, if detected, would prove that neutrinos are Majorana fermions and provide the direct evidence for lepton number violation. If such decay would exist in nature, then $\pi^-\pi^-\to ee$ and $\pi^-\to\pi^+ ee$…