Calculation of the N to Delta electromagnetic transition matrix element

TL;DR

This paper reports lattice QCD calculations of the electromagnetic transition amplitudes between the nucleon and delta resonance, focusing on the ratio of electric quadrupole to magnetic dipole components, using quenched and 2-flavor theories.

Contribution

It provides the first lattice QCD determination of the $R_{EM}$ ratio for the $ o$ transition considering both quenched and dynamical quark effects.

Findings

Calculated $R_{EM}$ ratio from lattice QCD

Comparison between quenched and 2-flavor results

Insights into nucleon to delta transition structure

Abstract

We present results on the ratio of electric quadrupole to magnetic dipole amplitudes, $R_{EM}={\cal G}_{E2}/{\cal G}_{M1}$, for the transition $\gamma N to \Delta$ from lattice QCD. We consider both the quenched and the 2-flavor theory.