Electromagnetic form factor via Minkowski and Euclidean Bethe-Salpeter amplitudes

TL;DR

This paper compares electromagnetic form factors calculated via Minkowski and Euclidean Bethe-Salpeter amplitudes and finds that the light-front approach closely matches the Minkowski results, unlike the Euclidean method.

Contribution

It demonstrates that the light-front wave function approach yields form factors nearly identical to Minkowski space calculations, highlighting its effectiveness over Euclidean methods.

Findings

Euclidean Bethe-Salpeter form factors differ significantly from Minkowski ones.

Light-front wave function form factors closely match Minkowski results.

Euclidean approach's static approximation does not improve agreement.

Abstract

The electromagnetic form factors calculated through Euclidean Bethe-Salpeter amplitude and through the light-front wave function are compared with the one found using the Bethe-Salpeter amplitude in Minkowski space. The form factor expressed through the Euclidean Bethe-Salpeter amplitude (both within and without static approximation) considerably differs from the Minkowski one, whereas form factor found in the light-front approach is almost indistinguishable from it.