We review the description of the lowest-energy nucleon excitation—the Δ (1232)-resonance.
Much of the recent experimental effort has been focused on the precision measurements of …

We review recent progress in the investigation of the electroexcitation of nucleon
resonances, both in experiment and in theory. We describe current experimental facilities …

Recent experimental and theoretical advancements have led to significant progress in our
understanding of the electromagnetic structure of nucleons (N), nucleon excitations (N∗) …

Abstract High-precision 1 H (e, e′ p) π 0 measurements at Q 2= 0.126 (GeV/c) 2 are
reported, which allow the determination of quadrupole amplitudes in the γ* N→ Δ transition; …

To determine nonspherical angular-momentum amplitudes in hadrons at long ranges (low Q
2), data were taken for the p (¯ e, e'p) π 0 reaction in the Δ region at Q 2= 0.060 (GeV/c) 2 …

We measured angular distributions of recoil-polarization response functions for neutral pion
electroproduction for W= 1.23 GeV at Q 2= 1.0 (GeV/c) 2, obtaining 14 separated response …

Helicity amplitudes for the γ* N→ Δ transition are calculated using the cloudy bag model. A
correction for center-of-mass motion is carried out using a modified Peierls-Thouless …

The large N c limit provides relations that can be used to calculate the γ* N→ Δ (1232)
quadrupole form factors at low and intermediate Q 2 under the assumption of the pion cloud …

The determination of nonspherical angular momentum amplitudes in nucleons at long
ranges (low Q 2) was accomplished through the p (e→, e'p) π 0 reaction in the Δ region at Q …

Until now, calculations of the E 2 amplitude in the N→ Δ transition using the spatial current
operator have differed considerably from those using the one-body charge operator and …