Nucleon-to-Delta transition form factors in chiral effective field theory using the complex-mass scheme

TL;DR

This paper computes the electromagnetic transition form factors from nucleons to Delta resonances using advanced chiral effective field theory methods, incorporating complex-mass scheme for systematic power counting, and fits the results to experimental data.

Contribution

It introduces a novel combination of the complex-mass scheme with chiral effective field theory to calculate transition form factors systematically.

Findings

Form factors calculated to third chiral order.

Good agreement with empirical data.

Systematic power counting achieved.

Abstract

We calculate the form factors of the electromagnetic nucleon-to-$\Delta$-resonance transition to third chiral order in manifestly Lorentz-invariant chiral effective field theory. For the purpose of generating a systematic power counting, the complex-mass scheme is applied in combination with the small-scale expansion. We fit the results to available empirical data.