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Title: Extracting nucleon magnetic moments and electric polarizabilities from lattice QCD in background electric fields

Nucleon properties are investigated in background electric fields. As the magnetic moments of baryons affect their relativistic propagation in constant electric fields, electric polarizabilities cannot be determined without knowledge of magnetic moments. This is analogous to the experimental situation, for which determination of polarizabilities from the Compton amplitude requires subtraction of Born terms. With the background field method, we devise combinations of nucleon correlation functions in constant electric fields that isolate magnetic moments and electric polarizabilities. Using an ensemble of anisotropic gauge configurations with dynamical clover fermions, we demonstrate how both observables can be determined from lattice QCD simulations in background electric fields. We obtain results for the neutron and proton, however, our study is currently limited to electrically neutral sea quarks. The value we extract for the nucleon isovector magnetic moment is comparable to those obtained from measuring lattice three-point functions at similar pion masses.
Authors:
 [1] ;  [2] ;  [3] ;  [1]
  1. Department of Physics, College of William and Mary, Williamsburg, Virginia 23187-8795 (United States)
  2. (United States)
  3. Maryland Center for Fundamental Physics, Department of Physics, University of Maryland, College Park, Maryland 20742-4111 (United States)
Publication Date:
OSTI Identifier:
21409870
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 81; Journal Issue: 5; Other Information: DOI: 10.1103/PhysRevD.81.054502; (c) 2010 The American Physical Society
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; AMPLITUDES; ANISOTROPY; CORRELATION FUNCTIONS; ELECTRIC FIELDS; MAGNETIC MOMENTS; MASS; NEUTRONS; PIONS; POLARIZABILITY; PROTONS; QUANTUM CHROMODYNAMICS; QUARKS; RELATIVISTIC RANGE; SIMULATION BARYONS; BOSONS; ELECTRICAL PROPERTIES; ELEMENTARY PARTICLES; ENERGY RANGE; FERMIONS; FIELD THEORIES; FUNCTIONS; HADRONS; MESONS; NUCLEONS; PHYSICAL PROPERTIES; PSEUDOSCALAR MESONS; QUANTUM FIELD THEORY