Meson Photoproduction on Polarized Deuterium

A successful description of the nucleon excitation spectrum is a basic test of how well the underlying forces are understood. Recent Lattice-QCD calculations have supported the predictions of $SU(6)\times0(3)$ quarks models for many ``missing'' levels which have yet to be observed. Most of these are predicted to couple weakly to the well-studied $\pi N$ channel. Stronger couplings are predicted to other decay channels such as $\pi\pi N$, $\rho N$ and $K\Lambda$, which can be studied in photo-production. Polarization observables on both polarized proton and neutron targets are needed to disentangle reaction mechanisms at the amplitude level. While polarized-proton data is comparatively abundant, data on the polarized neutron has been essentially non-existent. During 2011-2012, JLAB carried out experiment E06-101 (g14 run with CLAS) to measure pseudoscalar-meson photo-production reactions using circularly and linearly polarized beam on an HD-Ice target, where quasi-free kinematics of the ($\sim 25\%$ polarization) longitudinally polarized deuterium may be used to approximate a polarized neutron. This talk summarizes the status of on-going analyses of the $\pi p$, $K\Lambda$, $K^0\Sigma^0$, $\pi\pi n$, $\pi\Delta$, and $\rho n$ channels to extract relevant polarization observables.