Phenomenology of nuclear forces

  • After correcting for the electromagnetic interaction, the forces between nucleons (pp, nn, or np) in the same state are almost the same.
  • Almost the same: Charge-independence is slightly broken.
  • Equality between the pp and nn forces: Charge symmetry.
  • Equality between pp/nn force and np force: Charge independence.
  • Better notation: Isospin symmetry, invariance under rotations in isospin