Speakers
Description
The first excited state of the nucleon dominates many nuclear phenomena at energies above the pion-production threshold and plays a prominent role in the physics of the strong interaction. The study of the N →Δ transition form factors (TFFs) allows to shed light on key aspects of the nucleonic structure that are essential for the complete understanding of the nucleon dynamics. An experimental program for the study of the TFFs is currently ongoing in Hall C at JLab. A first phase of measurements has focused on intermediate momentum transfers, utilizing the SHMS and the HMS spectrometers, while upcoming measurements will extend the range of the kinematic reach to low four-momentum transfer squared. The experimental program focuses on a region where the mesonic cloud dynamics are dominant and rapidly changing. More specifically, it will provide high precision measurements of the quadrupole TFFs, that have emerged as the experimental signature for the presence of non-spherical components in the nucleon wave function and will allow to decode the underlying system dynamics responsible for their existence. The measurements will offer a test bed for chiral effective field theory calculations and benchmark data for the lattice QCD calculations, and will allow to test the theoretical prediction that the Electric and the Coulomb quadrupole amplitudes converge as Q2 →0.
