|Author||Charap, J. M. ♦ Tausner, M. J.|
|Source||United States Department of Energy Office of Scientific and Technical Information|
|Subject Keyword||PHYSICS ♦ ENERGY RANGE ♦ FEYNMAN DIAGRAM ♦ FIELD THEORY ♦ INTERACTIONS ♦ NUCLEAR MODELS ♦ NUCLEONS ♦ PERTURBATION THEORY ♦ QUANTUM MECHANICS ♦ SCATTERING ♦ SCATTERING AMPLITUDE ♦ SPECTRAL FUNCTIONS|
|Abstract||The scattering of nucleons at energies below the meson production threshold is discussed; the amplitude is a sum of five terms, each proportional to a different spin invariant. A comparison in perturbation theory, between the field-theoretic amplitude and that from potential theory enables a conclusion to be made that a potental that will reproduce the field-theoretic amplitude through the twomeson exchange contribution exists. This potential is a sum of five terms and is "local" in the sense that for a suitable choice of the spin-dependent operators, their coefficients are energy-independent. The potential is derived apart from radiative and rescattering corrections; it is again observed that the static limit ( mu /M - 0) is not well defined. The spectral functions for the potential are calculated. Rescattering corrections are discussed and, assuming simple analyticity properties for Feynman graphs, are shown not to destroy the locality of the potential. It is not yet possible to furnish a proof independent of perturbation theory that a potential exists, as was done for spinless particles, because the necessary dispersion rela tions have not been proved; it is not even known for which choice of spin invariants they might be expected to hold. Some clues as to this choice of "proper" spin invariants are afforded by the limitations imposed in order that the fourth-order potential be energy- independent. (auth)|
|Learning Resource Type||Article|
|Publisher Department||Univ. of Chicago|
|Organization||Univ. of Chicago|
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