Baryon transition current structure (N(1520) electric quadrupole amplitude) revisited: Insights from Patterson function analysis

The transition-current structure associated with the N(1520) electric quadrupole amplitude is investigated using Patterson-function analysis applied directly to empirical transition form-factor data GE. Because the reconstruction is derived entirely from experimental input, the resulting spatial distribution is obtained without introducing model-dependent assumptions. The reconstructed Patterson density exhibits a pronounced central maximum of 39.7 fm⁻⁶ and a half-maximum radius of 0.0467 fm, indicating a highly localized transition-current distribution. The density remains non-negative throughout the reconstructed region and shows only modest fluctuations over the interval r = 0.047–0.14 fm. Two- and three-dimensional reconstructions further confirm that the transition current is concentrated near the origin with limited spatial extension. Comparison with previously published Patterson reconstructions of nucleons, mesons, nuclei, and baryon excitations places the N(1520) electric quadrupole amplitude among the most compact transition-current structures identified to date.