Title: Polarization observables as a tool for studying excited states the proton.

Dr. Philip Cole
Department of Physics, Idaho State University

I shall report on the NSTAR program in Hall B of JLab on using polarization observables as an incisive tool for extracting parameters of baryon resonances, such as the underlying spin and parity. Baryon resonances or N*s are excited states of three quarks, where the ground state is the proton or neutron.

The scientific purpose of the NSTAR program is to improve the understanding of the underlying quark degrees of freedom, especially in the higher resonance regions, where we expect to uncover many of missing baryon resonances that mainly decay through multi-meson channels. With the high-quality beam of circularly- and linearly-polarized photons onto unpolarized and polarized proton and deteurium targets, and coupled with the nearly complete solid angle coverage of the Hall-B Spectrometer, we will extract the differential cross sections and associated polarization observables obtained by the photoproduction of vector mesons and kaons at center of mass energies of 1.7 to 2.2 GeV. The talk will primarily present the photon beam aspects of the excited baryon program.

UT Arlington Physics