Nucleons with chiral loops
Abstract
This article extends the analysis of the lowenergy structure of Green functions in QCD to processes with one external nucleon. We calculate various nucleon matrix elements of quark currents and determine the elastic πN scattering amplitude T_{πN } for offshell pions to one loop. As an application of our representation of T_{πN } we evaluate the difference ∆_{R} between the amplitude overlineD at the ChengDashen point and the scalar form factor σ(2 M_{π2}). The obtained result is a factor of 50 too small to explain the difference between the value of σ extracted from elastic πN scattering and the value obtained from the baryon mass spectrum.
 Publication:

Nuclear Physics B
 Pub Date:
 October 1988
 DOI:
 10.1016/05503213(88)901083
 Bibcode:
 1988NuPhB.307..779G