Effective Field Theory and Isospin Violation in Few-Nucleon Systems

I discuss the leading and subleading isospin--breaking three--nucleon forces in the chiral effective field theory framework. I have discussed the leading and subleading isospin-violating 3NFs. The leading contributions are generated by one- and two-pion exchange diagrams with their strength given by the strong neutron-proton mass difference. The subleading corrections are again given by one- and two-pion exchange diagrams, driven largely by the charged-to-neutral pion mass difference and also by the electromagnetic neutron-proton mass difference and the dimension two electromagnetic LEC f1. In the future, these isospin-breaking forces should be used to analyze few-nucleon systems based on chiral EFT