The use of skyrmions for two-nucleon systems

We first define our goals for studying the nucleon-nucleon force with skyrmions by discussing briefly the general issue of the formulation of nuclear physics using degrees of freedom based on quarks and gluons. A short review is then given of the use of the skyrmion description for single-hadrons in order to prepare the way for the application of this method to two-nucleon systems. A detailed discussion of the use of the London-Heitler method - which applies the B = 1 hedgehog solution, in one form or another, to the B = 2 case -is presented. This includes such issues as the use of higher-order terms in the lagrangian, the incorporation of higher-order dynamic terms, and the mutual distortion of hedgehog solutions in the B = 2 system. Last, we discuss three mechanisms that yield some degree of attraction in the central potential: (i) the admixture of states involving nucleon-Δ and Δ-Δ components along with the asymptotic nucleon-nucleon ones; (ii) the use of a form of the London-Heitler method that takes into account the proper symmetries of the two-skyrmion state; and (iii) the treatment of internal excitations of the single-baryon and their effects on the nucleon-nucleon force. (Author)