Related papers: Lepton decay constants of light mesons
The double lepton pair decay modes of the K_L meson are analyzed including all contributions of order p^6 in Chiral Perturbation Theory. The experimentally established e^+ e^- e^+ e^- mode and the recently observed e^+ e^- mu^+ mu^- mode…
This paper summarizes the recent calculations of the masses and decay constants of the pseudoscalar mesons at the two-loop level, or NNLO, in Partially Quenched Chiral Perturbation Theory (PQxPT). Possible applications include chiral…
We present a comprehensive study of weak transition form factors and decay observables of the $B_s$ meson in transitions to pseudoscalar ($P$) and vector ($V$) mesons. The $B_s \to P(V)$ form factors are calculated using the self-consistent…
In the present work, we use optical theorem to calculate the next-to-leading order corrections to the QCD spectral densities directly in the QCD sum rules for the pseudoscalar and scalar $B_c$ mesons. We take the experimental data as guides…
We investigate the in-medium properties of pseudoscalar and vector mesons with the light-light and heavy-light quarks in a light-front quark model, using the in-medium quark properties computed by the quark-meson coupling model. Both models…
The leptonic decay-constant ratio $f_K/f_\pi$ is calculated from lattice-QCD simulations using $N_f=2+1$ dynamical fermion flavors in the clover-improved formulation and 2-HEX smearing. The simulations were performed for a range of…
The decay modes and fractions in particle physics are some quantitative and very complex questions. Various decays of particles and some known decay formulas are discussed. Many important decays of particles and some known decays of…
The light scalar mesons in a variety of approaches are briefly reviewed, as well as their description in the Resonance-Spectrum Expansion and related coupled-channel formalisms. A recent multichannel modelling of the light scalars is…
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…
New Physics can show up in various well-known processes already studied in the Standard Model, in particular by modifying decay rates to some extent. In this work, I examine leptonic decays of $\Upsilon$ vector resonances of bottomonium…
I calculate the form factors describing semileptonic and penguin induced decays of B mesons into light pseudoscalar and vector mesons. The form factors are calculated from QCD sum rules on the light-cone including contributions up to twist…
Recent lattice studies on (semi-)leptonic kaon decays towards a precise determination of V_us are reviewed. Attention is given to recent unquenched calculations and consistency of their results with chiral perturbation theory.
The calculation of lepton decay constants and electromagnetic form factors of pion and kaon is performed in the framework of relativistic hamiltonian dynamics. The different model wave function is used. Wave function parameters are fixed…
In the framework of the Standard Model we present predictions for partial widths, double and single differential distributions, and forward--backward lepton asymmetries for four-leptonic decays $B^- \to \mu^+\mu^- {\bar \nu}_e\, e^-$, $B^-…
We study the decay properties of a heavy-light meson. We reformulate the decay amplitudes for the heavy-light systems and find a new way to calculate decay rates. Applying this formulation, we find a new sum rule for the radiative decays of…
We construct an effective Lagrangian which describes interactions of heavy and light hadrons utilizing the chiral flavor symmetry for light quarks and heavy quark symmetry. For both light and heavy sector we include pseudo scalars, vectors…
The transition form factors of the radiative decays of the heavy tensor mesons to heavy pseudoscalar and heavy vector mesons are calculated in the framework of the light cone QCD sum rules method at the point $Q^2=0$. Using the obtained…
We introduce an effective lagrangian including negative and positive parity heavy mesons containing a heavy quark, light pseudoscalars, and light vector resonances, with their allowed interactions, using heavy quark spin-flavour symmetry,…
Spectrum of masses of light pseudoscalar ($\pi, K, \eta, \eta'$) and vector ($\rho, K^*, \omega, \phi$) mesons can be explained on the base of the following assumptions: (1) analytical confinement (propagators of quarks and gluons are…
An extended $U(3)_L\bigotimes U(3)_R$ chiral effective field theory which includes pseudoscalar and vector meson nonets as dynamic variables is presented. The theory combines a hidden symmetry approach with a general procedure of including…