AbstractsPhysics

The two pion exchange contribution to π⁺ production in proton-proton collisions at 970 Mev.

by Melvin. Month




Institution: McGill University
Department: Department of Physics.
Degree: PhD
Year: 1964
Keywords: Physics.
Record ID: 1511875
Full text PDF: http://digitool.library.mcgill.ca/thesisfile116584.pdf


Abstract

Two distinct theoretical attempts have been made to describe the neutron distribution for the process of π⁺ production in proton-proton collisions at 970 Mev. The OPE and OBE Models both are one particle exchange theories. Trying to extend the former, using its production vertex technique, leads to divergent integrals. However, using in part the perturbation methods of the OBE model, a finite two pion exchange term is realized. It is found, contrary to the assumption made in the OBE model, that the two pion term gives a contribution greater than the one pion term. (In calculating the two pion term the π-π interaction in the crossed channel is neglected. This has been taken into account in the OBE model by the exchange of multipion resonances considered as particles in the usual sense.) This result invalidates the claim that the OBE model completely accounts for the dominant contributions to the production process under consideration here. In the light of this fact it is suggested that the fundamental tenets of the OBE model be subjected to critical scrutiny. Further, because of the close relationship between the OPE model and the one pion term of the OBE model, it is inferred that the former is also in need of reevaluation. [...]