相关论文: $NNK$ and $\Lambda\Lambda K$ Amplitudes in Chiral …

We perform an evaluation of the p-wave amplitudes of meson-baryon scattering in the strangeness S=-1 sector starting from the lowest order chiral Lagrangians and introducing explicitly the Sigma^* field with couplings to the meson-baryon…

We calculate the lambda-nucleon scattering phase shifts and mixing angles by applying time-ordered perturbation theory to the manifestly Lorentz-invariant formulation of SU(3) baryon chiral perturbation theory. Scattering amplitudes are…

We report on the recent studies of leading order baryon-baryon interactions in covariant baryon chiral perturbation theory. In the strangeness $S=0$ sector, one can achieve a rather good description of the Nijmegen $np$ phase shifts with…

We discuss in this talk aspects of \bar{K}N plus coupled channels dynamics with special emphasis on the \Lambda(1405) resonance and isovector resonances in the same energy region. We comment on several experimental reactions giving rise to…

Chiral perturbation theory and its unitarized versions have played an important role in our understanding of the low-energy strong interaction. Yet, so far, such studies typically deal exclusively with perturbative or nonperturbative…

The neutral Kaon decays Ks->gamma gamma and Kl->pi0 gamma gamma are very sensitive to higher order loop effects of Chiral Perturbation Theory (ChPT). New measurements of the NA48 experiment show that ChPT contributions of O(p^6) cannot be…

We develop a dynamical coupled-channels model of K^- p reactions, aiming at extracting the parameters associated with hyperon resonances and providing the elementary antikaon-nucleon scattering amplitudes that can be used for investigating…

We consider the relation between the breakdown scale of chiral perturbation theory, $\Lambda_\chi$, for large values of $N$ (flavor), and the scale associated with ``new" physical thresholds. This question is addressed using both the linear…

In this talk, we present our recent work on the $K\ra\pi \bar{l} l$ decays in a combined framework of chiral perturbation theory and Large--$N_c$ QCD under the dominance of a minimal narrow resonance structure. The proposed description…

We study the scaling with the number of colors $N_c$ of the weak amplitudes mediating kaon mixing and decay, in the limit of light charm masses ($m_u=m_d=m_s=m_c$). The amplitudes are extracted directly on the lattice for $N_c = 3-7$ (with…

We consider meson-baryon interactions in S-wave with strangeness -1. This is a sector populated by plenty of resonances interacting in several two-body coupled channels. We consider a large set of experimental data, where the recent…

In pure chiral perturbation theory (ChPT) the couplings of higher order Lagrangian terms are running parameters and hence can be determined only empirically from various low-energy hadronic processes. While this scenario works well for…

Threshold amplitudes are considered for multi-particle production in $\phi^k$ and $O(N) ~\phi^4$ theories. It is found that the disappearance of tree-level threshold amplitudes of $2$ on-shell particles producing a large number of particles…

We study the coupling of the Lambda(1520)= Lambda* resonance to the \bar K* vector meson and nucleon. This coupling is not directly measured from the resonance decay, but is expected to be important in hyperon production reactions, in…

Pion and photo-induced inelastic reactions off protons are studied in a multichannel partial-wave analysis. Properties of nucleon and $\Delta$ resonances are derived and compared to previous analyses. Amplitudes are shown for transitions to…

Dai and Pennington have performed a comprehensive analysis of essentially all pion and kaon pair production data from two-photon collisions below 1.5 GeV, including all high statistics results from Belle, as well as the older data from Mark…

We study the long-distance dominated K_L -> pi^+ pi^- gamma decay at O(p^6) in Chiral Perturbation Theory. The complete calculation of the O(p^6) loop magnetic amplitude is carried out. At this chiral order the model dependent part of the…

The $s-$wave meson-baryon scattering amplitude is analyzed for the strangeness $S=-1$ and isospin I=0 sector in a Bethe-Salpeter coupled channel formalism incorporating Chiral Symmetry. Four two-body channels have been considered: $\bar K…

In this talk I review the theory of electromagnetic decays of the ground state baryon multiplets with oneheavy quark, calculated using Heavy Hadron Chiral Perturbation Theory. The M1 and E2 amplitudes for (S^{*}-> S gamma), (S^{*} -> T…

We use both old and new theoretical developments in QCD dispersion relation constraints on the scalar form factor in the decay K --> \pi l \nu_l to obtain constraints on the strange quark mass. The perturbative QCD side of the calculation…