This content will become publicly available on January 26, 2016
First measurement of the helicity asymmetry E in η photoproduction on the proton
Results are presented for the first measurement of the double-polarization helicity asymmetry E for the η photoproduction reaction γ p → η p. Data were obtained using the FROzen Spin Target (FROST) with the CLAS spectrometer in Hall B at Jefferson Lab, covering a range of center-of-mass energy W from threshold to 2.15 GeV and a large range in center-of-mass polar angle. As an initial application of these data, the results have been incorporated into the J\"ulich model to examine the case for the existence of a narrow Ν* resonance between 1.66 and 1.70 GeV. The addition of these data to the world database results in marked changes in the predictions for the E observable using that model. As a result, further comparison with several theoretical approaches indicates these data will significantly enhance our understanding of nucleon resonances.
- Arizona State Univ., Tempe, AZ (United States)
- Arizona State Univ., Tempe, AZ (United States). et al.
- Publication Date:
- OSTI Identifier:
- Report Number(s):
- JLAB-PHY-15-2096; DOE/OR/23177-3461; arXiv:1507.00325
Journal ID: ISSN 0370-2693
- Grant/Contract Number:
- Published Article
- Journal Name:
- Physics Letters. Section B
- Additional Journal Information:
- Journal Volume: 755; Journal Issue: C; Journal ID: ISSN 0370-2693
- Research Org:
- Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
- Sponsoring Org:
- USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
- Country of Publication:
- United States
- eta photoproduction; polarization observable; helicity asymmetry
Enter terms in the toolbar above to search the full text of this document for pages containing specific keywords.