Measurements of spin observables  in pseudo scalar-meson polarized photo-production using polarized deutrons in solid HD

  Tsuneo Kageya 
     (Thomas Jefferson National Accelerator Facility, Newport News, Va 23606)

Recent Lattice QCD calculations have supported the long standing quark model expectation of many more excited states of the nucleon than have been experimentally observed. These missing states are expected to be broad and overlapping each other and require detailed partial wave analyses (PWA) to disentangle. Measurements of many polarization observables are required to constrain PWA. Furthermore, for evaluation of isoscalar and isovector contributions to photocouplings of 1/2-isospin resonances, photocouplings both off protons and neutrons are needed. To address the latter, the g14/E06-101 experiment at Jlab completed data taking in 2012 using the CLAS with circularly and linearly polarized photons incident on longitudinally polarized neutrons in solid deuterium-hydride (HD) frozen-spin targets. Analysis has been on-going for the data with linearly as well as circularly polarized photon beams.    Calibrations of CLAS detectors, energy loss corrections due to the materials around the target, tagger energy corrections and momentum corrections have been performed for better qualify of data analysis.    Preliminary analyses for double-spin asymmetries on deutron, aiming to the ones on neutron will be discussed. For some production channels using circularly polarized photon on longitudinally polarized nucleon target like γ + n(p) → π − +  p (p),  π+ + π− + n (p),  E asymmetries are obtained.   The channel, γ + n(p) → π − +  p (p) using the linearly polarized photons obtaining Ʃ and G asymmetries could be discussed as well.