Fang, JF (reprint author), E China Normal Univ, Dept Phys, Shanghai 200241, Peoples R China.
[Fang, Ji-Feng] E China Normal Univ, Dept Phys, Shanghai 200241, Peoples R China
; [Fang, Ji-Feng] Chinese Acad Sci, Kavli Inst Theoret Phys China, Beijing 100190, Peoples R China
The pion contributions to the coupling C-0 of pioniess EFT are studied via both non-relativistic and relativistic forms of chiral effective field theory for nuclear forces. A definite item in the 2N-reducible component of the box diagram is shown to be dominant over the 2N-irreducible (potential) ones due to the pinching of low-lying nucleon poles, and this anomalous mapping between pionless and pionfull MFT's occurs right within the non-relativistic regime. A natural strategy for renormalization of the pion full theory emerges as a byproduct through the interactive analysis of the box diagram. Such mapping perspective may shed some light on the efficient organization of the pionfull effective field theory for nuclear forces.