Theory of the low-energy pion--nucleon interaction

Technical Report · Mon Aug 01 04:00:00 EDT 1977

DOI:https://doi.org/10.2172/5297191· OSTI ID:5297191

Banerjee, M. K.; Cammarata, J. B.

A once-subtracted form of the Low equation for the pion-nucleon scattering amplitude is derived, with PCAC used to define the amplitude when one pion is off the mass shell. The static approximation is not made and both the seagull terms and the antinucleon contribution (z-graphs) are retained. The theory is applied to calculate the S-wave amplitudes in the elastic scattering region. Good agreement is found with the phase shift fits to the data when we use mod(g/sub ..pi../(4M/sup 2/)) = 11.69 and 25.5 MeV for the ..pi..N sigma-commutator. The implications of this work for the analysis of low-energy elastic scattering of pions from nuclei are discussed. In particular, it is pointed out how this work establishes the presence of a Laplacian term in the pion-nucleus optical potential with a magnitude that is fixed from the value of the sigma-commutator.

• Research Organization: Maryland Univ., College Park (USA). Dept. of Physics and Astronomy
• DOE Contract Number: EY-76-S-05-5126
• OSTI ID: 5297191
• Report Number(s): ORO-5126-18
• Country of Publication: United States
• Language: English

Related Subjects

653003* -- Nuclear Theory-- Nuclear Reactions & Scattering
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
AMPLITUDES
CHARGED-PARTICLE REACTIONS
ELASTIC SCATTERING
EQUATIONS
HADRON REACTIONS
HADRON-HADRON INTERACTIONS
INTERACTIONS
LOW EQUATION
MESON REACTIONS
MESON-BARYON INTERACTIONS
MESON-NUCLEON INTERACTIONS
NUCLEAR POTENTIAL
NUCLEAR REACTIONS
NUCLEI
OPTICAL MODELS
PARTIAL WAVES
PARTICLE INTERACTIONS
PCAC THEORY
PION REACTIONS
PION-NUCLEON INTERACTIONS
S WAVES
SCATTERING
SCATTERING AMPLITUDES