https://cds.cern.ch/record/150509/files/198404302.pdf

Chiral Perturbation Theory: Expansions in the Mass of the Strange Quark

The Bonn Meson Exchange Model for the Nucleon Nucleon Interaction

Nuclear forces can be systematically derived using effective chiral Lagrangians consistent with the symmetries of QCD. I review the status of the calculations for two- and three-nucleon forces and their applications in few-nucleon systems. I also address issues like the quark mass dependence of the nuclear forces and resonance saturation for four-nucleon operators.

/pdf/modern-theory-of-nuclear-forces-436h635pm0.pdf

Modern theory of nuclear forces

https://cds.cern.ch/record/192078/files/198811120.pdf

The Role of Resonances in Chiral Perturbation Theory

We present the first nucleon-nucleon potential at next-to-next-to-next-to-leading order (fourth order) of chiral perturbation theory. Charge dependence is included up to next-to-leading order of the isospin-violation scheme. The accuracy for the reproduction of the nucleon-nucleon $(NN)$ data below $290\text{\ensuremath{-}}\text{MeV}$ lab energy is comparable to the one of phenomenological high-precision potentials. Since $NN$ potentials of order three and less are known to be deficient in quantitative terms, the present work shows that the fourth order is necessary and sufficient for a $NN$ potential reliable up to $290\phantom{\rule{0.3em}{0ex}}\text{MeV}$. The new potential provides a promising starting point for exact few-body calculations and microscopic nuclear structure theory (including chiral many-body forces derived on the same footing).

Accurate charge dependent nucleon nucleon potential at fourth order of chiral perturbation theory

Compilation of Coupling Constants and Low-Energy Parameters. 1978 Edition

The results from a potential model for the low-energy $\mathrm{NN}$ interaction based on Regge-pole theory are presented. The forces are due to the dominant parts of the $\ensuremath{\pi}$, $\ensuremath{\eta}$, ${\ensuremath{\eta}}^{\ensuremath{'}}$, $\ensuremath{\rho}$, $\ensuremath{\omega}$, $\ensuremath{\varphi}$, $\ensuremath{\delta}$, $\ensuremath{\epsilon}$, ${S}^{*}$ trajectories in the complex $J$ plane, which are the well-known one-boson-exchange forces. Novel features are the dominant $J=0$ parts of the Pomeron, $f$ ${f}^{\ensuremath{'}}$ and ${A}_{2}$ trajectories. At the Reggeon vertices we use exponential form factors, as suggested by high-energy fits. The Pomeron, $f$, and ${f}^{\ensuremath{'}}$ trajectories lead essentially to repulsive central Gaussian potentials. This soft-core, partially nonlocal potential model fits the $\mathrm{NN}$ data with $\frac{{\ensuremath{\chi}}^{2}}{\mathrm{data}}=2.09$, which is lower than any other model we know of. The $\mathrm{NN}$ coupling constants have reasonable values, and the contributions of the Pomeron and tensor trajectories agree with estimates from high-energy fits.

Low-energy nucleon-nucleon potential from Regge-pole theory

From a combined analysis of nucleon-nucleon and hyperon-nucleon scattering with a one-boson-exchange potential model the $\ensuremath{\Lambda}N$ and $\ensuremath{\Sigma}N$ results are presented. The model consists of local potentials due to exchanges of members of the pseudoscalar and vector-meson nonets and the scalar meson $\ensuremath{\epsilon}$ taken as a unitary singlet. The multichannel Schr\"odinger equation is solved in configuration space with phenomenological hard-core potentials at short distances. The coupling constants are calculated via SU(3) with the coupling constants of the $\mathrm{NN}$ analysis as input. Charge-symmetry breaking between the $\ensuremath{\Lambda}p$ and $\ensuremath{\Lambda}n$ channels is included. A least-squares fit to the low-energy $\ensuremath{\Lambda}p$, ${\ensuremath{\Sigma}}^{+}p$, and ${\ensuremath{\Sigma}}^{\ensuremath{-}}p$ data yields a very satisfactory result. Predictions up to the pion production threshold are given, and, whenever possible, compared to the experimental data.

Baryon-baryon scattering in a one-boson-exchange-potential approach. I. Nucleon-nucleon scattering

Compilation of coupling constants and low-energy parameters

The $\mathrm{NN}$ and $\mathrm{YN}$ results are presented from a one-boson-exchange-potential model. It consists of local potentials due to exchanges of members of the pseudoscalar, vector, and scalar-meson nonets. SU(3) relations are assumed for the axial-vector couplings of the pseudoscalar mesons, for the electric and magnetic couplings of the vector mesons, for the direct couplings of the scalar mesons, and for the hard-core radii. In the fit to $\mathrm{NN}$ the nonstrange-meson-nucleon couplings are determined. The simultaneous $\mathrm{YN}$ analysis determines the $\frac{F}{D}$ ratios and the SU(3) parameters of the scalar-meson nonet. The description of the $\mathrm{NN}$ data is good ($\frac{{\ensuremath{\chi}}^{2}}{\mathrm{data}}=2.17$), and also of the $\ensuremath{\Lambda}p$, ${\ensuremath{\Sigma}}^{+}p$, and ${\ensuremath{\Sigma}}^{\ensuremath{-}}p$ data up to the pion production threshold. Very close to the $\ensuremath{\Sigma}N$ threshold we find a $\ensuremath{\Lambda}N$ resonance, which is dominantly in the $^{3}D_{1}$ wave. The $\ensuremath{\Lambda}p$ cross section is maximal just below the ${\ensuremath{\Sigma}}^{+}n$ threshold at $E=2128.918$ MeV, in agreement with the experimental results of $\ensuremath{\Lambda}p$ final state interactions. The poles belonging to the $\ensuremath{\Lambda}p$ resonance are located on the second Riemann sheet at $E=2131.77\ifmmode\pm\else\textpm\fi{}i2.39$ MeV.

Baryon-baryon scattering in a one-boson-exchange-potential approach. III. A nucleon-nucleon and hyperon-nucleon analysis including contributions of a nonet of scalar mesons

M. M. Nagels

Papers

Compilation of Coupling Constants and Low-Energy Parameters. 1978 Edition

Low-energy nucleon-nucleon potential from Regge-pole theory

Baryon-baryon scattering in a one-boson-exchange-potential approach. I. Nucleon-nucleon scattering

Compilation of coupling constants and low-energy parameters

Baryon-baryon scattering in a one-boson-exchange-potential approach. III. A nucleon-nucleon and hyperon-nucleon analysis including contributions of a nonet of scalar mesons