Virtual Compton scattering and neutral pion electroproduction in the resonance region up to the deep inelastic region at backward angles

We have made the first measurements of the virtual Compton scattering (VCS) process via the H(e, e'p)γ exclusive reaction in the nucleon resonance region, at backward angles. Results are presented for the W-dependence at fixed Q[superscript 2] =1 GeV[superscript 2] and for the Q[superscript 2]...

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Bibliographic Details
Main Authors: Zhou, Z. -L., Zhao, J., Suleiman, R., Rowntree, D., Liyanage, N., Gilad, Shalev, Gao, J., Gao, Haiyan, Fissum, K. G., Bertozzi, William
Other Authors: Massachusetts Institute of Technology. Department of Physics
Format: Article
Language:en_US
Published: American Physical Society 2010
Online Access:http://hdl.handle.net/1721.1/51779
https://orcid.org/0000-0003-2713-7800
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Summary:We have made the first measurements of the virtual Compton scattering (VCS) process via the H(e, e'p)γ exclusive reaction in the nucleon resonance region, at backward angles. Results are presented for the W-dependence at fixed Q[superscript 2] =1 GeV[superscript 2] and for the Q[superscript 2] dependence at fixed W near 1.5 GeV. The VCS data show resonant structures in the first and second resonance regions. The observed Q[superscript 2] dependence is smooth. The measured ratio of H(e, e'p)γ to H(e, e'p)π0 cross sections emphasizes the different sensitivity of these two reactions to the various nucleon resonances. Finally, when compared to real Compton scattering (RCS) at high energy and large angles, our VCS data at the highest W (1.8-1.9 GeV) show a striking Q[superscript 2] independence, which may suggest a transition to a perturbative scattering mechanism at the quark level.