Charge-Independence Breaking in the Two-Pion-Exchange Nucleon-Nucleon Force

Abstract

Charge-independence breaking due to the pion-mass difference in the (chiral) two-pion-exchange nucleon-nucleon force is investigated. A general argument based on symmetries is presented that relates the charge-symmetric part of that force to the proton-proton case. The static potential linear in that mass difference is worked out as an explicit example by means of Feynman diagrams, and this confirms the general argument.

Comments: 10 pages, latex, 1 figure -- epsfig.sty required -- To appear in Phys. Rev. C