Related papers: Resonances from meson-meson scattering in U(3) CHP…
We perform a systematic study of two-meson form factors of the scalar, vector, and anti-symmetric tensor types within the framework of the $U(3)$ resonance chiral theory. The complete perturbative form factors in both the…
We study meson resonances with quantum numbers J^P=1^+ in terms of the chiral SU(3) Lagrangian. At leading order a parameter-free prediction is obtained for the scattering of Goldstone bosons off vector mesons with J^P=1^- once we insist on…
We study SU(3)$_L\timesSU(3)_R$ chiral quark model of mesons up to the next to leading order of $1/N_c$ expansion. Composite vector and axial-vector mesons resonances are introduced via non-linear realization of chiral SU(3) and vector…
The classification of scalar and vector mesons is reviewed within the framework of the Resonance-Spectrum Expansion (RSE). This method allows a simple and straightforward description of non-exotic meson-meson scattering, incorporating the…
Non-exotic scalar-meson resonances in S-wave meson-meson scattering are studied in the light of a unitarised Schroedinger model. The resulting poles in the scattering matrices, by analytical continuation into the complex-energy plane, are…
We review recent studies of light scalar meson properties by means of unitarization techniques, obtained from dispersion theory, and applied to the Chiral Perturbation Theory expansion. In particular, light scalars do not follow the N_c…
We describe the behaviour at threshold of S-wave poles of the scattering matrix within a four-parameter model for non-exotic meson-meson scattering. This model accommodates all non-exotic mesons, hence also the light scalar mesons, as…
We briefly review how light meson resonances are described within one and two-loop Unitarized Chiral Perturbation Theory amplitudes and how, close to Nc=3, light vectors follow the Nc behavior of $q\bar q$ mesons whereas light scalars do…
We study physics on $\rho(770)$ and $\omega(782)$ in framework of chiral constituent quark model. The effective action is derived by proper vertex method, which can capture all order information of chiral expansion. The $N_c^{-1}$ expansion…
We study the \eta' N interaction within a chiral unitary approach which includes \pi N, \eta N and related pseudoscalar meson-baryon coupled channels. Since the SU(3) singlet does not contribute to the standard interaction and the \eta' is…
We calculate the T-matrices of pseudoscalar meson octet-baryon scattering to one-loop order in SU(3) heavy baryon chiral perturbation theory. The pertinent combinations of low-energy constants are determined by fitting to phase shifts of…
By means of unitarized Chiral Perturbation Theory it is possible to obtain a remarkable description of meson-meson scattering amplitudes up to 1.2 GeV, and generate poles associated to scalar and vector resonances. Since Chiral Perturbation…
The leading $1/N_c$ behaviour of Unitarised Chiral Perturbation Theory distinguishes the nature of the $\rho$ and the $\sigma$. At one loop order the $\rho$ is a ${\bar q}q$ meson, while the $\sigma$ is not. However, semi-local duality…
We extend the 1/N_c expansion meson-baryon scattering formalism to cases in which the final state contains more than two particles. We first show that the leading-order large N_c processes proceed through resonant intermediate states (e.g.,…
We study whether light scalar meson nonet can survive in large values of Nc through observing how scattering amplitudes behave as Nc increases from 3 within a unitarized chiral approach. We obtain the result that vector mesons such as rho…
Based on the recent phenomenological analysis done by M. Mojzis, Eur. Phys. Jour. {\bf C2} (1998) 182, of $\pi N $ scattering within the framework of Heavy Baryon Chiral Perturbation Theory we predict, after a suitable unitarization of the…
We study meson-baryon scattering with strangeness -1 in unitary chiral perturbation theory. Ten coupled channels are considered in our work, namely $\pi^0 \Lambda$, $\pi^0 \Sigma^0$, $\pi^- \Sigma^+$, $\pi^+ \Sigma^-$, $K^- p$, $\bar{K}^0…
We study s-wave meson-baryon scattering using the chiral unitary model. We consider $1/2^{-}$ baryon resonances as quasibound states of the low lying mesons ($\pi,K,\eta$) and baryons ($N,\Lambda,\Sigma,\Xi$). In previous works, the…
We describe a four-parameter model for non-exotic meson-meson scattering, which accommodates all non-exotic mesons, hence also the light scalar mesons, as resonances and bound states characterised by complex singularities of the scattering…
The problem of scalar mesons still remains a challenging puzzle, for which we do not even know which are the right pieces to set up. The proliferation of resonances (some of them are very broad and appear on top of hadronic thresholds) and…