Speaker
Description
The search for undiscovered excited states of the nucleon continues to be a focus of experiments at the Thomas Jefferson National Accelerator Facility (JLab). A large effort was done using the CEBAF Large Acceptance Spectrometer (CLAS) detector to provide the database, which will allow nearly model-independent partial wave analyses (PWA) to be carried out in the search for such states. Polarization observables play a crucial role in the effort, as they are essential in disentangling the contributing resonant and non-resonant amplitudes. Recent coupled-channel analyses have found strong sensitivity of the $K^{+}$+$\Lambda$ channel to several higher mass nucleon resonances. In 2008 and 2010, double-polarization data were taken at JLab using circularly and linearly polarized tagged photons incident on a longitudinally and transversely polarized frozen spin butanol target (FROST), operated at the temperature of 30~mK. The reaction products were detected in CLAS. This work is based on the analysis of FROST data and the extraction of the $E$, $L_x$, $L_z$, $T$, $F$, $T_x$, and $T_z$ asymmetries of the $K^{+}\Lambda$ and $K^{+}\Sigma^{0}$ final states and their comparison to predictions of recent multipole analyses. There are very few published measurements of the $T$ asymmetry and none for the $E$, $L_x$, $L_z$, $F$, $T_x$, and $T_z$ asymmetries for the $K^{+}\Lambda$ final state. The $K^{+}\Sigma^{0}$ final state has no published measurements for these asymmetries. This work is the first of its kind and will significantly broaden the world database for these reactions.
