GDH 2002: Proceedings of the Second International Symposium on the Gerasimov-Drell-Hearn Sum Rule and the Spin Structure of the Nucleon

Angela Biselli is a contributing author "STUDY OF THE Δ (1232) USING DOUBLE-POLARIZATION ASYMMETRIES."

Article abstract: An extensive experimental program to measure the spin structure of the nucleons is underway in Hall B at Jefferson Lab using a polarized electron beam incident on polarized hydrogen and deuterium targets, consisting of frozen NH3 and ND3 material. Spin degrees of freedom offer the possibility to test, in an independent way, existing models of resonance electroproduction. The most accessible resonance is the Δ(1232) since it does not overlap with other states and decays strongly via π emission. The present analysis select the Δ+(1232) in the exclusive channel from data of the EG1 run period, taken in the Fall of 1998, to extract single and double spin asymmetries in a Q2 range from 0.5 to 1.5 GeV2/c2. Results of the asymmetries are presented as a function of the center of mass decay angles of the π0 and compared with the unitary isobar model MAID, the dynamic model by Sato and Lee and the effective Lagrangian theory by Davidson and Mukhopadhyay.