Threshold Pion Production from Proton-proton Collisions
Threshold Pion Production from Proton-proton Collisions

Author:

Publisher:

Published: 1995

Total Pages: 134

ISBN-13:

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We showed that the threshold production of [pi]°pp, [pi]np, and [pi]d from proton-proton collisions can be consistently described by a model consisting of pion s-wave rescattering and N{bar N} pair-terms of heavy-meson exchanges. The large difference between [sigma]{sup tot}(pp 2![pi]d) and [sigma]{sup tot}(pp 2![pi]+np) is understood from the orthogonality of the deuteron and the np scattering wave functions. In a calculation using the Paris potential, we find that the data can be reproduced best by using a soft [pi]NN form factor with [Delta] = 650 MeV for a monopole form. This is consistent with our earlier studies of pion production in the A-excitation region. A paper describing this result was submitted for publication.

The Two Pion Exchange Contribution to + Production in Proton-proton Collisions at 970 Mev
The Two Pion Exchange Contribution to + Production in Proton-proton Collisions at 970 Mev

Author: Melvin Month

Publisher:

Published: 1964

Total Pages:

ISBN-13:

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"Two distinct theoretical attempts have been made to describe the neutron distribution for the process of [pi]+ 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 [pi]-[pi] 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. [...]" --