Date of Award:


Document Type:


Degree Name:

Doctor of Philosophy (PhD)



Committee Chair(s)

Jack E. Chatelain


Jack E. Chatelain


The differential cross section for a neutron-proton collision forming an electron-positron pair is calculated. The interaction between the neutron and proton is assumed to be pseudo-scalar and that between the proton and the pair electromagnetic. The interaction between the pair and the neutron is assumed negligible.

The methods used to obtain the matrix elements of the process follows that of Möller. The calculation is therefore based on retarded interaction and is relativistic. In obtaining the square of the matrix elements the initial and final polarization states were not considered. The usual projection operator methods were then applied to the intermediate states which led to traces and trace products.

The traces were calculate on an IBM 7090 computer with the read-out being of alphabetic form. The output consisted of dot products of four vectors, with the four factors specifying the energy and momentum of the various particle states.

A second computer program was written to determine the momentum and energy among the particle states for a special symmetrical scattering case. The data obtained from this program was used as input for a third computer program which obtained a plot of differential cross section versus incident proton energy, the proton energy running from 960 Mev to 1065 Mev.

The results depicted by the graphs are discussed and additional work recommended.