Sum rules for magnetic moments and polarizabilities in QED and chiral effective-field theory

Journal Article · Tue Nov 01 04:00:00 EST 2005 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PhysRevD.72.094014· OSTI ID:20713828

Holstein, Barry R ^[1]; Pascalutsa, Vladimir; Vanderhaeghen, Marc ^[1]

---

1. Theory Group, JLab, 12000 Jefferson Ave, Newport News, Virginia 23606 (United States)

We elaborate on a recently proposed extension of the Gerasimov-Drell-Hearn (GDH) sum rule which is achieved by taking derivatives with respect to the anomalous magnetic moment. The new sum rule features a linear relation between the anomalous magnetic moment and the dispersion integral over a cross section quantity. We find some analogy of the linearized form of the GDH sum rule with the 'sideways dispersion relations'. As an example, we apply the linear sum rule to reproduce the famous Schwinger's correction to the magnetic moment in QED from a tree-level cross section calculation and outline the procedure for computing the two-loop correction from a one-loop cross section calculation. The polarizabilities of the electron in QED are considered as well by using the other forward-Compton-scattering sum rules. We also employ the sum rules to study the magnetic moment and polarizabilities of the nucleon in a relativistic chiral effective field theory (EFT) framework. In particular we investigate the chiral extrapolation of these quantities.

• OSTI ID: 20713828
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 9 Vol. 72; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CHIRAL SYMMETRY
CHIRALITY
COMPTON EFFECT
CORRECTIONS
DISPERSION RELATIONS
ELECTRONS
EXTRAPOLATION
MAGNETIC MOMENTS
NUCLEONS
POLARIZABILITY
QUANTUM ELECTRODYNAMICS
RELATIVISTIC RANGE
SUM RULES