Background field approach to electromagnetic properties of baryons

Abstract

We investigate the self-energies of particles in an external magnetic field $B$. The dependence is generally of the type $\sqrt{P(B)}$ with $P$ a polynomial in $B$ and the participating masses. The non-analytic point depends on the mass and charge constellations, is unproblematic for stable particles but constrains the linear energy shift approximation for resonances. We calculate the $B$ dependent self-energies of the nucleon and $\Delta (1232)$-isobar in the SU(2) covariant chiral perturbation theory and outline a way to obtain finite volume corrections to the nucleon anomalous magnetic moment without using the three point function method. We show that finite volume corrections might explain present discrepancies of lattice QCD and chiral perturbation theory results in the small pion mass region.

revised, Refs added

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• Chiral Effective-Field Theory in the Delta(1232) Region: Pion Electroproduction on the Nucleon
• Extracting Nucleon Magnetic Moments and Electric Polarizabilities from Lattice QCD in Background Electric Fields
• Dirac and Pauli form factors from lattice QCD
• The nucleon and Delta(1232) form factors at low momentum-transfer and small pion masses
• Hadrons in Strong Electric and Magnetic Fields
• External Momentum, Volume Effects, and the Nucleon Magnetic Moment
• Volume Effects for Pion Two-Point Functions in Constant Electric and Magnetic Fields
• Current Renormalization in Finite Volume
• Electromagnetic moments of quasi-stable particle

Cited by in corpus (1)

• Chiral extrapolation and finite-volume dependence of the hyperon vector couplings