Determining the axial radius of the nucleon from data on pion electroproduction

Journal Article · Mon Sep 28 04:00:00 EDT 1992 · Physical Review Letters; (United States)

DOI:https://doi.org/10.1103/PhysRevLett.69.1877· OSTI ID:7199673

Bernard, V ^[1]; Kaiser, N ^[2]; Meissner, U ^[3]

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1. Physique Theorique, Centre de Recherches Nucleaires et Universite Louis Pasteur de Strasbourg, BP 20 Cr, 67037 Strasbourg CEDEX 2 (France)
2. Physik Deparment T30, Technische Universitaet Muenchen, James Franck Strasse, D-8046 Garching (Germany)
3. Institut fuer Theoretische Physik, Universitaet Bern, Sidlerstrasse 5, CH-3012 Bern (Switzerland)

We discuss a low-energy theorem of threshold pion electroproduction which allows one to determine the axial root-mean-square radius {ital r}{sub {ital A}} of the nucleon. We show that at the same order where the radius appears, pion loops induce a small correction to the momentum dependence of the electric dipole amplitude {ital E}{sub 0+}{sup ({minus})}. This correction amounts to a decrease of the axial mean-square radius by 5% from the electroproduction data and allows one to explain the small discrepancy to the values determined from (anti)neutrino-proton scattering data.

• OSTI ID: 7199673
• Journal Information: Physical Review Letters; (United States), Journal Name: Physical Review Letters; (United States) Vol. 69:13; ISSN PRLTA; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

662330 -- Photon & Charged-Lepton Interactions with Hadrons-- (1992)
662410* -- Properties of Baryons & Baryon Resonances-- (1992-)
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANGULAR MOMENTUM
BARYONS
BASIC INTERACTIONS
BOSONS
CHIRAL SYMMETRY
ELECTROMAGNETIC INTERACTIONS
ELECTROPRODUCTION
ELEMENTARY PARTICLES
FERMIONS
FORM FACTORS
HADRONS
INTERACTIONS
LEPTON-BARYON INTERACTIONS
LEPTON-HADRON INTERACTIONS
LEPTON-NUCLEON INTERACTIONS
LIMITING VALUES
MESONS
NEUTRINO-NUCLEON INTERACTIONS
NUCLEONS
PARTICLE INTERACTIONS
PARTICLE KINEMATICS
PARTICLE PRODUCTION
PARTICLE PROPERTIES
PERTURBATION THEORY
PIONS
PSEUDOSCALAR MESONS
SPIN
SYMMETRY