Nuclear forces from chiral EFT: the unfinished business

Ruprecht Machleidt 
University of Idaho

In recent years, there has been substantial progress in the derivation
of nuclear forces from chiral effective field theory (EFT). Accurate two-nucleon
forces have been constructed at next-to-next-to-next-to-leading order (N3LO)
and applied (together with three-nucleon forces at N2LO) to nuclear few- and many-body
systems---with a fair deal of success. This may suggest that the 80-year old nuclear
force problem has finally been cracked. Not so! Some pretty basic issues
are still unresolved. In my talk, I will focus on the two most pressing ones,
namely, subleading many-body forces and the proper renormalization of the
two-nucleon potential.