Related papers: Decay Spectrum of $K^+ \to e^+ \nu_{e}\gamma$
An analysis is given of the decay $\mu \to e+ \gamma$ in an MSSM extension with a vectorlike generation. Here mixing with the mirrors allows the possibility of this decay. The analysis is done at the one loop level with the exchange of…
We investigate the rare radiative eta decay modes eta -> pi+ pi- gamma gamma and eta -> pi0 pi0 gamma gamma within the framework of chiral lagrangians at o(p^4) and present photon spectra for both processes.
We apply the infinite mass effective theory, when a heavy quark mass tends to infinity, and Chiral perturbation theory at the quark level, based on the extended Nambu -- Jona -- Lasinio model with linear realization of chiral $U(3)\times…
The form factors for the $B-->\pi$ transition are evaluated in the entire momentum transfer range by using the constraints obtained in the framework combining the heavy quark expansion and chiral symmetry for light quarks and the quark…
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 $\phi \to K^+K^-,K^{0}_{L},K^{0}_{S},K^{0}\bar K^0$ decays are studied using the method of phenomenological chiral Lagrangians. Calculated values for partial widths for these decay channels are compared with available experimental data.
We calculate the branching ratios of the $K^+ \to \pi^0 l^+ \nu_l\gamma (l = e, \mu)$ decays, and the T-odd triple momenta correlations $\xi=\vec{q}\cdot[\vec{p}_l \times \vec{p}_\pi]/M^3_K$, due to the electromagnetic final state…
Weak transition form factors among heavy pseudoscalar mesons are investigated within a relativistic quark model formulated on the light-front. It is shown that the light-front result derived in the time-like region for the matrix elements…
The dependence of the $K^+ \to \pi^0 l^+ \nu_l \gamma$ decay width on the $T$-odd kinematical variable, $ \xi = {\vec q \cdot [\vec p_l \times \vec p_\pi]} / {M^3}$, is studied at the tree and one-loop levels of Standard Model. It is shown…
We study the transition form factors of the light vector to pseudoscalar mesons as functions of the momentum transfer $q^2$ within the light-front quark model. With these form factors, we calculate the decay branching ratios of all possible…
In the covariant light-front quark model, we investigate the $B_c\to h_c, \chi_{c0,1,2}$ form factors. The form factors are evaluated in space-like kinematic region and are recasted to the physical region by adopting the exponential…
In this article, we study the radiative transitions among the vector and scalar heavy quarkonium states with the covariant light-front quark model. In calculations, we observe that the radiative decay widths are sensitive to the constituent…
Experiment 865 at the Brookhaven AGS has observed the decay K^+ -> e^+ nu mu^+ mu^-. The branching ratio extracted is (1.72 +/- 0.37(stat) +/- 0.17(syst) +/- 0.19(model)) x 10^{-8} where the third term in the error results from the use of a…
Transverse muon polarization in the $K^+ \rightarrow \mu^+ \nu \gamma$ decay is calculated in the model with scalar and pseudo scalar four-Fermi interactions. Combined with a similar calculation in the $K^+ \rightarrow \mu^+ \nu \pi^0$…
The KLOE results on the measurement of the transition form factors of the eta and pi0 mesons in phi Dalitz decays are presented, and the determination of the Gamma(eta->gamma gamma) in gamma gamma processes is also reported. The prospects…
The $\gamma^\ast \Lambda \to \Sigma^0$ transition form factors are investigated within the light--cone QCD sum rules method. Using the most general form of the interpolating current of $\Sigma^0$ baryon and the distribution amplitudes of…
A QCD relativistic potential model is employed to compute the decay rate and the photon spectrum of the process $B^- \to \mu^- {\bar \nu}_\mu \gamma$. The result ${\cal B}(B^- \to \mu^- {\bar \nu}_\mu \gamma) \simeq 1 \times 10^{-6}$…
We report on the first observation of the decay KL -> pi0 ee gamma by the KTeV E799 experiment at Fermilab. Based upon a sample of 48 events with an estimated background of 3.6 +/- 1.1 events, we measure the KL -> pi0 ee gamma branching…
Motivated by the experimental measurements of $D^0$ radiative decay modes we have proposed a model to study the $D^0\to \bar{K}^{*0}\gamma$ decay, by establishing a link with $D^0\to \bar{K}^{*0}V$ $(V=\rho^0,\, \omega)$ decays through the…
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…