Related papers: Eta-eta' mixing in U(3) chiral perturbation theory
We obtain explicit expressions for the \eta and \eta' masses and decay constants using U_L(3) x U_R(3) chiral perturbation theory at next-to-leading order in a combined expansion in p^2 and 1/Nc. A numerical fit of the parameters appearing…
The systematic large N_c limit within chiral perturbation provides an optimal eta-eta' mixing angle of about -27 degrees at leading order in p^2. In this frame, agreement with the data can be reached with higher order corrections of about…
We present a calculation of the $\eta$-$\eta'$ mixing in the framework of large-$N_c$ chiral perturbation theory. A general expression for the $\eta$-$\eta'$ mixing at next-to-next-to-leading order (NNLO) is derived, including…
We include the eta-prime in chiral perturbation theory without employing 1/N_c counting rules. The method is illustrated by calculating the masses and decay constants of the Goldstone boson octet (pions, kaons, eta) and the singlet…
A systematic study of the $\eta$-$\eta'$ mixing in Large-$N_c$ chiral perturbation theory is presented with special emphasis on the role of the next-to-next-to-leading-order contributions in the combined momentum, quark-mass, and $1/N_c$…
We reconcile the 1/N_c expansion with the observed eta-eta' mass spectrum. The chiral corrections introduced for that purpose are natural and consistent with the octet-singlet mixing angle theta=-(22\pm 1)^{\circ} extracted from…
The dominant decay mode of the eta-prime, eta-prime -> eta pi pi, is investigated within the framework of infrared regularized U(3) chiral perturbation theory up to fourth chiral order and including one-loop corrections. We find reasonable…
We study the $\eta$-$\eta'$ mixing up to next-to-next-to-leading-order in $U(3)$ chiral perturbation theory in the light of recent lattice simulations and phenomenological inputs. A general treatment for the $\eta$-$\eta'$ mixing at higher…
Using chiral perturbation theory and the large-$N_c$ expansion, we obtain expressions for the $\eta'$ mass and $\eta - \eta'$ mixing in terms of low-energy chiral Lagrangian parameters. This is accomplished through an intermediate step of…
The decays eta/eta' -> pi pi pi and eta' -> eta pi pi are studied up to leading and next-to-leading order within the framework of U_L(3)xU_R(3) Chiral Perturbation Theory. The analysis incorporates important features of the eta-eta' system,…
We determine the $\eta-\eta'$ mixing angle via a procedure relatively independent of theoretical assumptions by simultaneously fitting $\eta- eta'$ reactions involving the anomaly--$\eta,\eta'\to\gamma\gamma, \pi^+\pi^-\gamma$. We extract…
We discuss $\pi^0$ -$\eta$ mixing and its implication for $\epsilon'/ \epsilon$ to next-to-leading order in the low-energy expansion. The big effect due to $\eta$-$\eta'$ mixing is shown to be largely cancelled by other contributions…
Although eta-eta' mixing is qualitatively well understood as a consequence of the U(1)_A anomaly in QCD together with a broken SU(3) flavor symmetry, until recently the values of decay and mixing parameters of the eta and eta' were only…
We study the temperature dependence of the eta and eta' meson masses within the framework of U(3)_L x U(3)_R chiral perturbation theory, up to next-to-leading order in a simultaneous expansion in momenta, quark masses and number of colours.…
The approach to the eta'-eta complex employing chirally well-behaved quark-antiquark bound states and incorporating the non-Abelian axial anomaly of QCD through the generalization of the Witten-Veneziano relation, is extended to finite…
In this work the analysis of mixing parameters of the system involving eta, eta' mesons and some third massive state G is carried out. We use the generalized mixing scheme with three angles. The framework of the dispersive approach to…
The $\eta-\eta^{\prime}$ mixture is discussed in the chiral bag model to calculate the pseudoscalar octet-singlet mixing angle consistent with the experimental data. The color anomaly is taken into account with the modified boundary…
A two mixing angle description of the pseudoscalar decay constants associated to the $\eta$-$\eta^\prime$ system is used to parametrize the theoretical amplitudes of the radiative decays $(\eta,\eta^\prime)\to\gamma\gamma$ and the coupling…
We shed light upon the eta' mass in nuclear matter in the context of partial restoration of chiral symmetry, pointing out that the U_{A}(1) anomaly effects causes the eta'-eta mass difference necessarily through the chiral symmetry…
We include in a systematic way the eta' in baryon chiral perturbation theory. The most general relativistic effective Lagrangian describing the interaction of the lowest lying baryon octet with the Goldstone boson octet and the eta' is…