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

Journal Article · Mon Aug 01 04:00:00 EDT 2005

DOI:https://doi.org/10.1103/PhysRevD.72.094014· OSTI ID:842282

Holstein, Barry; Pascalutsa, Vladimir; Vanderhaeghen, Marc

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 EFT framework. In particular we investigate the chiral extrapolation of these quantities.

• Research Organization: Thomas Jefferson National Accelerator Facility, Newport News, VA
• Sponsoring Organization: USDOE Office of Energy Research (ER)
• DOE Contract Number: AC05-84ER40150
• OSTI ID: 842282
• Report Number(s): JLAB-THY-05-393; DOE/ER/40150-3540
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ELECTRONS
EXTRAPOLATION
MAGNETIC MOMENTS
NUCLEONS
SUM RULES