Selected nucleon form factors and a composite scalar diquark

Journal Article · Thu Jun 01 04:00:00 EDT 2000 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PhysRevC.61.065207· OSTI ID:20216935

Bloch, J C. R. ^[1]; Roberts, C D ^[1]; Schmidt, S M ^[1]

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1. Physics Division, Argonne National Laboratory, Argonne, Illinois 60439-4843 (United States)

A covariant, composite scalar diquark, Fadde'ev amplitude model for the nucleon is used to calculate pseudoscalar, isoscalar- and isovector-vector, axial-vector and scalar nucleon form factors. The last yields the nucleon {sigma} term and on-shell {sigma}-nucleon coupling. The calculated form factors are soft, and the couplings are generally in good agreement with experiment and other determinations. Elements in the dressed-quark-axial-vector vertex that are not constrained by the Ward-Takahashi identity contribute {approx}20% to the magnitude of g{sub A}. The calculation of the nucleon {sigma} term elucidates the only unambiguous means of extrapolating meson-nucleon couplings off the meson mass shell. (c) 2000 The American Physical Society.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL
• OSTI ID: 20216935
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 6 Vol. 61; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
COMPOSITE MODELS
FORM FACTORS
NUCLEONS
QUARK MODEL
THEORETICAL DATA