Off-shell πN amplitudes via a multichannel separable potential

Journal Article · Mon Jul 01 04:00:00 EDT 1974 · Annals of Physics

DOI:https://doi.org/10.1016/0003-4916(74)90434-5· OSTI ID:4263352

Londergan, J. T. ^[1]; McVoy, K. W. ^[2]; Moniz, Ernest J. ^[3]

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1. Univ. of Wisconsin, Madison, WI (United States). Dept. of Physics; Indiana Univ., Bloomington, IN (United States). Dept. of Physics
2. Univ. of Wisconsin, Madison, WI (United States). Dept. of Physics
3. Univ. of Pennsylvania, Philadelphia, PA (United States). Dept. of Physics; Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Center for Theoretical Physics, Dept. of Physics and Lab. for Nuclear Science

The off-shell pion-nucleon transition matrix is a basic ingredient in theories of pion-nuclear interactions which, in the absence of fundamental theory of πN dynamics, must be obtained by a phenomenological extrapolation from the available on-shell data. As one means of performing such an extrapolation, we explore a multichannel separable potential model with the property that the off-shell elastic scattering amplitude is generated directly from the measured elastic-channel phase shifts. The off-shell πN partial-wave transition amplitudes determined by this procedure are compared with those calculated by Landau and Tabakin using a one-channel absorptive separable potential. We find that the absorptive separable potential approach provides a physically unreasonable off-shell extrapolation at energies where the on-shell amplitude is highly inelastic, and show that the difficulty is a direct consequence of the one-channel nature of that method. The multichannel extrapolation is free of these difficulties.

• Research Organization: Univ. of Wisconsin, Madison, WI (United States). Dept. of Physics
• Sponsoring Organization: US Atomic Energy Commission (AEC); National Science Foundation
• NSA Number: NSA-30-030731
• OSTI ID: 4263352
• Journal Information: Annals of Physics, Journal Name: Annals of Physics Journal Issue: 1 Vol. 86; ISSN 0003-4916
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

*PION-NUCLEON INTERACTIONS-- SCATTERING AMPLITUDES
CENTRAL POTENTIAL
COMPARATIVE EVALUATIONS
ELASTIC SCATTERING
N64260* --Physics (High Energy)--Particle Interactions & Properties (Theoretical)--Strong (Baryon No. = 1)
PARTIAL WAVES