The E2 N(yields)(Delta) transition from polarized Compton scattering
Abstract
The tensor interaction between the quarks in a proton is predicted to produce a D-wave component in its wave function, which breaks spherical symmetry and results in a static deformation for the proton's first excited state, the Delta resonance at approximately 320 MeV. The Delta is photo-excited mainly by M1 radiation. However, if its wavefunction contains a D-wave component, then the N approaches Delta transition can also be excited by E2 photons. The magnitude and sign of the E2/M1 mixing ration in the N approaches Delta transition are quite sensitive to the internal structure of the proton and have been of great interest in recent years. The extraction of a small E2 amplitude is complicated by the presence of non resonant background contributions. In elastic (Compton) scattering of polarized photons most background contributions cancel in the polarization asymmetry. This has not been previously exploited, since such measurements are technically demanding. Extraction of the E2 component is presently underway.
- Publication:
-
Presented at the 13th International Conference on Particles and Nuclei
- Pub Date:
- 1993
- Bibcode:
- 1993panu.conf.....S
- Keywords:
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- Channel Noise;
- Compton Effect;
- Elastic Scattering;
- Electron Scattering;
- Photoexcitation;
- Photons;
- Polarization (Waves);
- Protons;
- Scattering Amplitude;
- Asymmetry;
- Gamma Ray Lasers;
- Gamma Rays;
- Quarks;
- Radioactive Decay;
- Static Deformation;
- Wave Functions;
- Atomic and Molecular Physics