Related papers: Rho meson properties in the Nambu-Jona-Lasinio mod…
Within the context of an extended Nambu - Jona-Lasinio model, we analyze the role of the axial-vector $a_1(1260)$ and $a_1(1640)$ mesons in the decay $\tau\to\nu_\tau \rho^0\pi^-$. The contributions of pseudoscalar $\pi$ and $\pi (1300)$…
We present a novel framework for analyzing unstable composite particles using Green's functions and dispersion relations. As an illustrative example, we explore the $\rho$ vector meson decay process $\rho\to\pi\pi$ within the Nambu -- Jona…
Properties of mesons are investigated within the Nambu--Jona-Lasinio model. We include meson-loop corrections, which are generated via a systematic 1/N_c-expansion in next-to-leading order. We show that our scheme is consistent with chiral…
We investigate strong and radiative meson decays in a generalized Nambu--Jona-Lasinio model. The one loop order calculation provides a satisfactory agreement with the data for the mesonic spectrum and for radiative decays. Higher order…
The branching ratios and photon spectra of the rare processes rho(omega)-> pi^0 pi^0 gamma, rho(omega) -> eta pi^0 gamma are calculated in the framework of the standard local quark Nambu--Jona-Lasinio (NJL) model. Three types of diagrams…
In the extended NJL model the radiative decay widths of the radially excited states of the pseudoscalar $\pi$, $\eta$, and $\eta'$ mesons are calculated. The predictions for the decay widths of the processes…
The $\rho(1450)$ vector meson ($\rho^\prime$) is becoming increasingly important to properly describe precision observables. We analyse a set of decay modes and cross sections, in the low-energy regime, to determine the role played by this…
The decay widths of $V \to K(\pi) l \bar{\nu}_l $ are calculated within the Nambu--Jona-Lasinio model, where $V=K^*, \rho, \omega, \phi$ and $l=\mu, e$. The results are obtained using the previously fixed model parameters without…
The modification of the width of rho mesons due to in-medium decays and collisions is evaluated. The decay width is calculated from the imaginary part of the one-loop self-energy at finite temperature. The collision width is related to the…
The full and differential widths of the decay $\tau \rightarrow K^{0}K^{-}\nu_{\tau}$ are calculated in the framework of the extended Nambu-Jona-Lasinio model. The contributions of the subprocesses with the intermediate vector mesons…
The decay widths of $\rho' \to \pi\pi, \omega\pi, \rho\eta$, $\omega' \to \rho\pi, \omega\eta$ and $\pi' \to \rho\pi$ are recalculated within the extended NJL quark model. It is shown that the mass of $\rho'(1450)$ meson in the derived in…
The influence of mesonic fluctuations on quantities in the Nambu-Jona-Lasinio model is examined in different approximation schemes: an expansion in powers of 1/N_c and an expansion up to one-meson loop in the effective action formalism. It…
We compute the difference in decay widths of charged and neutral \rho(770) vector mesons. The isospin breaking arising from mass differences of neutral and charged \pi and \rho mesons, radiative corrections to \rho -> \pi\pi, and the \rho…
We find a general expression for the one-loop self-energy function of neutral $\rho$-meson due to $\pi^+\pi^-$ intermediate state in a background magnetic field, valid for arbitrary magnitudes of the field. The pion propagator used in this…
In the framework of the extended Nambu-Jona-Lasinio model, the processes $\tau \to \pi \pi \eta(\eta')\nu_\tau$ and $\tau \to \pi\eta\eta(\eta')\nu_\tau$ are considered taking into account mesons in the ground and first radially excited…
The Nambu--Jona-Lasinio model is investigated in the $1/N_c$ expansion with the dimensional regularization. At the four-dimensional limit the meson propagators have simple forms in the leading order of the $1/N_c$ expansion. Thus the next…
In this paper, the width of the decay $\tau \rightarrow K^{-}\pi^{0}\nu_{\tau}$ is calculated in the framework of the Nambu-Jona-Lasinio model. The contributions of the intermediate vector $K^{*}(892)$ and scalar $K_{0}^{*}(800)$ mesons are…
In a previous work, we proposed an extended Nambu--Jona-Lasinio (NJL) model including heavy quark flavors. In this work, we will calculate strong and radiative decays of vector mesons in this extended NJL model, including light $\rho$,…
The decay width of the process eta -> pi^0 gamma gamma is calculated in the framework of the Nambu-Jona-Lasinio model. The momentum dependence of quark loops is taken into account. Three types of diagrams are considered: quark box,…
Two-photon decays of rho and omega mesons and strong decays rho -> eta pi and omega -> pi pi are described in the quark Nambu-Jona-Lasinio(NJL) model in dense medium. Decays of rho-meson are especially interesting because they contain…