Long distance effects and strangeness in the nucleon

TL;DR

This paper analyzes the strange magnetic radius of the proton using chiral perturbation theory, highlighting the importance of energy scale separation and its implications for understanding nucleon magnetic properties.

Contribution

It introduces a momentum space separation method to distinguish low and high energy contributions in chiral calculations of nucleon properties.

Findings

Most chiral calculation contributions come from high energies outside effective field theory validity.

Low energy predictions align better with dispersive approaches.

Techniques help address longstanding puzzles in proton and Sigma+ magnetic moments.

Abstract

We discuss the calculation of the strange magnetic radius of the proton in chiral perturbation theory. In particular we investigate the low energy component of the loop integrals involving kaons. We separate the chiral calculation into a low energy part and a high energy component through use of a momentum space separation scale. This separation shows that most of the chiral calculation comes from high energies where the effective field theory treatment is not valid. The resulting low energy prediction is in better agreement with dispersive treatments. Finally, we briefly discuss magnetic moments and show how our techniques can help resolve an old puzzle in understanding the magnetic moments of the proton and Sigma^+.