Isoscalar NN spin-orbit potential from a Skyrme model with scalar mesons

As a first step toward circumventing the difficulty to obtain an attractive isospin-independent NN spin-orbit force from Skyrme-type models involving only pions, we investigate an improved Skyrme Lagrangian that incorporates the scalar-isoscalar meson ε which can be viewed as the cause behind the enhancement of the ππ S-wave. We find that at large distances, the main contribution to the spin-orbit potential comes from the scalar Lagrangian and it is found to be attractive. We briefly discuss how to pursue this work to finally obtain a medium-range attractive interaction.     

Multi-skyrmion states in the Skyrme model with a false vacuum potential

We study multi-skyrmion states using the Skyrme model with a false vacuum potential up to baryon number B=8 using the product ansatz.It is found that both the false and true vacuum potentials can result in a cluster structure for the multi-skyrmion states.We also analyze the effect of explicit chiral breaking on the masses and contour surfaces of the baryon number density of the multi-skyrmion states.     

Intermediate Range Attaction of NN Interaction from Clustering Effect in Skyrme Model

As two skyrmions overlap,a molecular-like binding may arise.This may be one of the main sources of missing intermediate range attraction in NN interaction.The attraction is found to be strong enough to form bound state of two nucleons.It seems then that one no longer needs to introduce phenomenologically scalar meson which has never been observed.     

NN potential with a six-quark core from the constituent quark model

A mesonic nucleon-nucleon potential from an effective quark interchange mechanism for non-overlapping nucleons is obtained from the constituent quark model. This is supplemented at short range by a phenomenological, non-mesonic potential describing the transition to a six-quark core with a discrete energy spectrum. NN phase shifts and low energy parameters are calculated and compared with data and phase shift analyses. Core parameters are extracted from the fits.     

Recent mathematical developments in the Skyrme model

In this review we present a pedagogical introduction to recent, more mathematical developments in the Skyrme model. Our aim is to render these advances accessible to mainstream nuclear and particle physicists. We start with the static sector and elaborate on geometrical aspects of the definition of the model. Then we review the instanton method which yields an analytical approximation to the minimum energy configuration in any sector of fixed baryon number, as well as an approximation to the surfaces which join together all the low energy critical points. We present some explicit results for B=2. We then describe the work done on the multibaryon minima using rational maps, on the topology of the configuration space and the possible implications of Morse theory. Next we turn to recent work on the dynamics of Skyrmions. We focus exclusively on the low energy interaction, specifically the gradient flow method put forward by Manton. We illustrate the method with some expository toy models. We end this review with a presentation of our own work on the semi-classical quantization of nucleon states and low energy nucleon–nucleon scattering.     

Canonical quantization of the Skyrme model

The canonical quantization of the Skyrme model is presented. Due to the complexities of the original set-up, first postulated by Rajeev, a new set of fields is found which satisfy a Lie algebra and for this reason, simplifies the study of the system. Using the new fields, the properties of the states under rotations are examined. As a result we re-derive the quantization of the coefficient of the Wess-Zumino action as an a priori consistency condition. We also find under what circumstances states with non-vanishing winding number behave like fermions.     

Asymmetric nuclear matter and Skyrme potential

The binding energy, symmetry energy, pressure, incompressibility, and the velocity of sound are calculated for asymmetric nuclear matter using Skyrme interaction SkO’. The behavior of these physical quantities is studied for different values of the asymmetry parameter α _τ , the density ρ, and the temperature T. Good agreement is obtained in comparison with previous theoretical estimates and experimental data. The text was submitted by the authors in English.