Document Type


Publication Date




Publication Title

Physical Review C






045204 (1-11)


The exclusive channel polarized proton(polarized e,e' p)π0 was studied in the first and second nucleon resonance regions in the Q2 range from 0.187 to 0.770 GeV2 at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). Longitudinal target and beam-target asymmetries were extracted over a large range of center-of-mass angles of the π0 and compared to the unitary isobar model MAID, the dynamic model by Sato and Lee, and the dynamic model DMT. A strong sensitivity to individual models was observed, in particular for the target asymmetry and in the higher invariant mass region. This data set, once included in the global fits of the above models, is expected to place strong constraints on the electrocoupling amplitudes A 1/2 and S 1/2 for the Roper resonance N (1400) P11, and the N(1535)S11 and N(1520)D13 states.


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Original Publication Citation

Biselli, A. S., Burkert, V. D., Amaryan, M. J., Asryan, G., Avakian, H., Bagdasaryan, H., . . . Zhao, Z. W. (2008). First measurement of target and double spin asymmetries for ep → epπ° in the nucleon resonance region above the Δ (1232). Physical Review C, 78(4), 045204. doi:10.1103/PhysRevC.78.045204


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