Related papers: Unitarity Constraints on effective interaction in …
A multi-channel algebraic scattering theory, to find solutions of coupled-channel scattering problems with interactions determined by collective models, has been structured to ensure that the Pauli principle is not violated. Positive…
Proton Compton scattering is analyzed with the chiral Lagrangian. Partial-wave amplitudes are obtained by an analytic extrapolation of subthreshold reaction amplitudes computed in chiral perturbation theory, where the constraints set by…
We derive a representation for the pion nucleon scattering amplitude that is valid to the fourth order of the chiral expansion. To obtain the correct analytic structure of the singularities in the low energy region, we have performed the…
The pion-nucleon coupling constants determine the strength of the long-range nuclear forces and play a fundamental part in our understanding of nuclear physics. While the charged- and neutral-pion couplings to protons and neutrons are…
We apply the effective field theory approach to the three-nucleon system. In particular, we consider S=1/2 neutron-deuteron scattering and the triton. We show that in this channel a unique nonperturbative renormalization takes place which…
After a brief survey of effective field theories, the linear sigma model is discussed as a prototype of an effective field theory of the standard model below the chiral-symmetry-breaking scale. Although it can serve as a toy model for the…
We give a brief review of the theoretical description of low energy pion-pion scattering by the combined use of Chiral Perturbation Theory and Roy equations, an update of the Regge parametrization of $\pi\pi$ cross sections at high…
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…
These lectures give an introduction to baryon chiral perturbation theory. I show in detail how to construct the chiral effective pion-nucleon Lagrangian in the one loop approximation. Particular emphasis is put on the physics related to…
After a general introduction to the structure of effective field theories, the main ingredients of chiral perturbation theory are reviewed. Applications include the light quark mass ratios and pion-pion scattering to two-loop accuracy. In…
We consider nucleon-nucleon (NN) interactions from chiral effective field theory. In this work we restrict ourselves to the elastic NN scattering. We apply the N/D method to calculate the NN partial waves taking as input the one-pion…
We introduce a new and well defined power counting for the effective field theory describing nucleon-nucleon interactions. Because of the large NN scattering lengths it differs from other applications of chiral perturbation theory and is…
The multichannel S- and P-wave amplitudes for the pion-pion scattering, constructed requiring analyticity and unitarity of the S-matrix and using the uniformization procedure, are elaborated using the dispersion relations with imposed…
We establish the framework for the comparison of $\pi K$ scattering amplitudes from SU(3) chiral perturbation theory with suitable dispersive representations which result from the combination of certain fixed-t dispersion relations with…
We study the S-wave interaction of mesons with baryons in the strangeness S=0 sector in a coupled channel unitary approach. The basic dynamics is drawn from the lowest order meson baryon chiral Lagrangians. Small modifications inspired by…
This paper contains the results of an analysis of recent low-energy pion-nucleon scattering experiments. Obtained are phase shifts, the pion-nucleon coupling constant and an estimate of the Sigma term.
We analyze elastic-pion nucleon scattering to third order in the so-called small scale expansion. It is based on an effective Lagrangian including pions, nucleons and deltas as active degrees of freedom and counting external momenta, the…
New physics contributions to the (anti)neutrino-nucleon elastic scattering process can be constrained by precision measurements, with controlled Standard Model uncertainties. In a large class of new physics models, interactions involving…
In the large $N_c$ approximation to $QCD$, the leading $\pp$ scattering amplitude is expressed as the sum of an infinite number of tree diagrams. We investigate the possibility that an adequate approximation at energies up to somewhat more…
The effect of the non-perturbative term is investigated for the pion-nucleon scattering. Including the self-energy of nucleon the cross section of the elastic scattering results in a constant value at the laboratory momentum $p_L \to…