Three-Pion Contribution to the Electromagnetic Structure of the Nucleon

Abstract

In this paper the contribution of three pions to the scalar electromagnetic form factors of the nucleon are computed by using the fixed source meson theory without rescattering corrections. The (7,3TT) interaction is taken phenomenologically as a point interaction. It is shown that for those values of the (y,3w) coupling constant compatible with photoproduction experiments, the experimental charge distribution could be roughly fitted with a cutoff in the dispersion integral of the order of 7 pion masses.

Pion Form Factors from Possible High-Energy Electron-Positron Experiments

“…3 , and they claim that double pion photoproduction puts an upper limit =6 for X. 5 At a given E the maximum of da is obtained for those configurations of the three final pions for which the area of the triangle formed with their momenta is maximum. For such configurations and for E = 500 Mev, we find, using a constant H and the above value for X, ^2a/^+^o).…”

“…The matrix element (3) for two pions is expressed in terms of the pion factor MiK 2 ) by 2 With our choice of the independent kinematical parameters the differential cross section can be written as J u (P a) ,P {2) ) =^(4o) (1) co (2) )-1/2 M(X 2 )(/> a) -/>*>). (5) The differential cross section, always in the center-of-mass frame, is given by…”

Effects of the Pion-Pion Interaction on Photonuclear Reactions

“…First of all, we postulate the phenomenological local Hamiltonian as 5 ) where ). is the effective coupling constant, A;.…”

Electromagnetic Structure of the Nucleon. III

“…We have obtained the 11M-correction of a 1 S (m 2 ) in (2·4) with (2·6). This is compared with af..,(m 2 ) in Fig.…”