Particles, Astrophysics, and Nuclear Physics Seminar
Q2 dependence of quadrupole strength in the \gamma*p -> \Delta(1232) -> p\pi0 transition
Thomas Jefferson National Accelerator Facility
Electroproduction of the \Delta(1232) can be used to study the mechanisms responsible for quark confinement and resonance formation. In particular, the Q2 dependence of the multipoles E1+ and M1+ in the N -> \Delta(1232) quadrupole transition is sensitive to the shape of the nucleon and the evolution from pion to quark degrees of freedom. Recent \pi0 electroproduction data taken using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab permit a complete separation of the response functions \sigmaTT and \sigmaLT , which show high sensitivity to the quadrupole strength. New experimental results for the ratios E1+/M1+ and S1+/M1+ are presented using a partial wave analysis over a Q2 range of 0.4 to 1.8 GeV2. Results will be compared to quark models as well as recent unitary models which include the dynamical effects of the pion cloud.
Wednesday, April 3, 2002
Gant Science Complex