相关论文: Two photon decays of scalar mesons in the quark NJ…
Within the framework of non-local quark model of Nambu--Jona-Lasinio type the two-photon decay of radial excited state of $\pi_0$-meson -- $\pi_0'$ -- is found to be $3.6\KeV$. The radial excitation of pion is described with the use of…
We use the QCD sum rules to evaluate the form factors associated with the semileptonic decays of $D_s$ and $D$ mesons into $f_0(980)$. We consider the $f_0(980)$ meson as a quark-antiquark state with a mixture of strange and light…
A chiral U(3)xU(3) Lagrangian, containing besides the usual meson fields their first radial excitations, is considered. The Lagrangian is derived by bosonization of the Nambu--Jona-Lasinio quark model with separable non-local interactions.…
It is argued that the search of the J/psi --> f0(980)omega and J/psi --> a0(980)rho decays and the more precise definition of B(J/psi --> f0(980)phi) are the urgent purposes in the J/\psi spectroscopy. It is shown that the study of the…
We work out the low-energy expansion of the anomalous $f_1(1285)\to\rho\gamma$ decay amplitude by using the Nambu--Jona-Lasinio model with $U(2)\times U(2)$ chiral symmetric four-quark interactions in the one-quark-loop approximation. The…
We shortly report on the two-photon decay width of the light $\sigma$-meson interpreted as a quarkonium state. Results are given in dependence on the $\sigma$-mass and the constituent mass of the light quark. The triangle quark-loop…
Within the QCD light-cone sum rule (LCSR) approach, we investigate the transition form factors of $D\rightarrow a_0(980)$ up to the twist-3 light-cone distribution amplitudes (LCDAs) of the scalar meson $a_0(980)$ in the two-quark picture.…
We demonstrate how most of the light $J^{P}=0^{+}$ spectrum below $2.0\,\mathrm{GeV}$ and their decays can be consistently described by the unitarized quark model incorporating the chiral constraints of Adler zeros and taking SU(3) breaking…
In this paper, we develop a general framework to study the meson-photoproductions of nucleons in the chiral quark model. The S and U channel resonance contributions are expressed in terms of the Chew-Goldberger-Low-Nambu (CGLN) amplitudes.…
The complementarity between Chiral Perturbation Theory and the Linear Sigma Model is exploited to study $\pi^0\pi^0$ production in $\phi$ radiative decays, where the effects of the $f_0(980)$ scalar resonance, and those of its more…
We estimate the rates for radiative transitions of the lightest scalar mesons f_0(980) and a_0(980) to the vector mesons rho and omega. We argue that measurements of the radiative decays of those scalar mesons can provide important new…
We study the mechanism of production of the light scalar mesons in the $D_s^+\to\pi^+\pi^- e^+\nu$ decays: $D_s^+\to s\bar s e^+\nu\to [\sigma(600)+f_0(980)] e^+\nu\to\pi^+\pi^- e^+\nu$, and compare it with the mechanism of production of…
Using the Nambu--Jona-Lasinio model with the $U(2)\times U(2)$ chiral symmetric effective four-quark interactions, we derive the amplitude of the radiative decay $f_1(1285) \to\pi^+\pi^-\gamma$, find the decay width $\Gamma…
Attention is paid to the production mechanisms of the light scalars that reveal their nature. In the linear sigma model it is revealed the chiral shielding of the \sigma(600) meson and shown that the \sigma field is described by its…
We study the photoproduction of scalar mesons close to the threshold of f_0(980) and a_0(980) using a unitary chiral model. Peaks for both resonances show up in the invariant mass distributions of pairs of pseudoscalar mesons. A discussion…
It is shown that the recent data on the $K^0_S K^+$ correlation in Pb-Pb interactions agree with the data on the $\gamma\gamma\to\eta\pi^0$ and $\phi\to\eta\pi^0\gamma$ reactions and support the four-quark model of the $a_0(980)$ meson. It…
The spectroscopic parameters and partial decay widths of the light mesons $ a_0(980) $ and $K_{0}^{\ast}(800)$ are calculated by treating them as scalar diquark-antidiquark states. The masses and couplings of the mesons are found in the…
We revisit the theoretical predictions for anomalous radiative decays of pseudoscalar and vector mesons. Our analysis is performed in the framework of the Nambu-Jona-Lasinio model, introducing adequate parameters to account for the…
Electromagnetic interactions of the ground and first radial excited states of $\eta$ and $\eta'$ mesons in the framework of the extended $U(3)\times U(3)$ NJL model are considered. The radial excitations are described with the help of…
Temperature dependence of the quark condensate is studied in the Nambu--Jona-Lasinio model with meson loops. Substantial differences are found compared to the results with quark loops only.