Measurement of the helicity dependence for the {gamma}p{yields}n{pi}{sup +} channel in the second resonance region
- Institut fuer Kernphysik, Universitaet Mainz, D-55099 Mainz (Germany)
- INFN, Sezione di Pavia, I-27100 Pavia (Italy)
- Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom)
- Insitut fuer Experimentalphysik, Ruhr-Universitaet Bochum, D-44801 Bochum (Germany)
The helicity dependence of the {gamma}p{yields}n{pi}{sup +} reaction has been measured for the first time in the photon energy range from 450 to 790 MeV. The experiment, performed at the Mainz Microtron (MAMI), used a 4{pi}-detector system, a circularly polarized, tagged photon beam, and a longitudinally polarized frozen-spin target. Although these polarized data are mainly sensitive to mechanisms involving the D{sub 13}(1520) resonance, a cusp structure at the {eta} production threshold can be clearly observed. These data are significantly different from the predictions of the existing multipole analyses and are used to determine the helicity amplitudes of the D{sub 13}(1520) and S{sub 11}(1535) resonances with improved accuracy.
- OSTI ID:
- 20863887
- Journal Information:
- Physical Review. C, Nuclear Physics, Vol. 74, Issue 4; Other Information: DOI: 10.1103/PhysRevC.74.045204; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
- Country of Publication:
- United States
- Language:
- English
Similar Records
Recoil Polarization and Beam-Recoil Double Polarization Measurement of {eta} Electroproduction on the Proton in the Region of the S{sub 11}(1535) Resonance
Near threshold photoproduction of {eta} mesons off the proton