On-shell approach to pion-nucleon physics

Journal Article · Sun Feb 01 04:00:00 EST 1998 · Physical Review, D

DOI:https://doi.org/10.1103/PhysRevD.57.1703· OSTI ID:573915

Steele, J V ^[1]; Yamagishi, H ^[2]; Zahed, I ^[1]

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1. Department of Physics, SUNY, Stony Brook, New York 11794 (United States)
2. 4 Chome 11-16-502, Shimomeguro, Meguro, Tokyo 153 (Japan)

We discuss an on-shell approach to pion-nucleon physics that is consistent order by order in a 1/f{sub {pi}} expansion with the chiral reduction formula, crossing, and relativistic unitarity. A number of constraints between the on-shell low-energy parameters are derived at tree level in the presence of the pion-nucleon sigma term, and found to be in fair agreement with experiment. We analyze the nucleon form factors, and the {pi}N{r_arrow}{pi}N scattering amplitude to one-loop, as well as {pi}N{r_arrow}{pi}{pi}N to tree level. We use the latter to derive a new constraint for the pion-nucleon sigma term at threshold. We compare our results to both relativistic and nonrelativistic chiral perturbation theory, and discuss the convergence character of the expansion in light of experiment. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 573915
• Journal Information: Physical Review, D, Journal Name: Physical Review, D Journal Issue: 3 Vol. 57; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
CHIRAL SYMMETRY
EXPANSION
FORM FACTORS
LORENTZ INVARIANCE
NUCLEONS
PERTURBATION THEORY
PION-NUCLEON INTERACTIONS
REDUCTION
SCATTERING AMPLITUDES
UNITARITY