Low-energy. pi. N scattering from N and. delta. poles and the low-energy theorems

Journal Article · Tue Jul 01 04:00:00 EDT 1980 · Phys. Rev., D; (United States)

DOI:https://doi.org/10.1103/PhysRevD.22.121· OSTI ID:5335221

Resele, G; Schmid, C

An investigation is made of the extent to which low-energy ..pi..N scattering is determined by the N and ..delta.. poles and the low-energy theorems. The on-shell amplitudes are expanded in (..mu../sub ..pi..//M/sub N/) at fixed (..nu../..mu../sub ..pi../) and (t/..mu../sub ..pi../ /sup 2/), and it is assumed that M/sub ..delta../-M/sub N/=O(..mu../sub ..pi../), in contrast to M/sub res/-M/sub N/=O(M/sub N/) for all other resonances. The invariant amplitudes are determined using fixed-t dispersion relations and are calculated to second order in (..mu../sub ..pi..//M/sub N/). The crossing-odd amplitudes are fully determined by the N and ..delta.. poles and the low-energy theorems. The crossing-even amplitudes receive undetermined background contributions described by three expansion coefficients. If they are fixed using the ''experimental'' scattering lengths, the resulting model is in fairly good agreement with experiment.

• Research Organization: Institut fuer Theoretische Physik, Eidgenoessische Technische Hochschule, Zuerich, Switzerland
• OSTI ID: 5335221
• Journal Information: Phys. Rev., D; (United States), Journal Name: Phys. Rev., D; (United States) Vol. 22:1; ISSN PRVDA
• Country of Publication: United States
• Language: English

Related Subjects

645204* -- High Energy Physics-- Particle Interactions & Properties-Theoretical-- Strong Interactions & Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AMPLITUDES
CHIRAL SYMMETRY
DISPERSION RELATIONS
HADRON-HADRON INTERACTIONS
INTERACTIONS
MATHEMATICAL MODELS
MESON-BARYON INTERACTIONS
MESON-NUCLEON INTERACTIONS
NUCLEAR MODELS
P WAVES
PARTIAL WAVES
PARTICLE INTERACTIONS
PCAC THEORY
PERTURBATION THEORY
PION-NUCLEON INTERACTIONS
S WAVES
SCATTERING AMPLITUDES
SHELL MODELS
SYMMETRY