Implications of chiral symmetry for scalar isoscalar channel and multi-   nucleon forces
  Chiral perturbation theory has to be substantially modified for the problem of nuclear forces. Loop effects dominate over tree level effects. The dominant behaviours in the scalar isoscalar channel and multi-nucleon forces are obtained in the chiral limit and for a small explicit breaking. 
Ramesh Anishetty, N.D. Hari Dass and H.S. Sharatchandra