Measurement of the E2/M1 Ratio in the N→Δ Transition using the reaction p(γγ ,p)πo

Beck, R. et al. (1997) Measurement of the E2/M1 Ratio in the N→Δ Transition using the reaction p(γγ ,p)πo. Physical Review Letters, 78(4), pp. 606-609. (doi: 10.1103/PhysRevLett.78.606)

Abstract

The small electric quadrupole E2 amplitude of the predominantly magnetic dipole M1 p -> Delta(1232) transition has been measured using 270 to 420 MeV tagged linearly polarized photons in the p(gamma,p)pi0 reaction at the Mainz Microtron MAMI. Differential cross sections and photon asymmetries were determined by measuring the recoil proton in the cylindrically symmetric 4pi detector DAPHNE. From the proton angular distributions the ratio E2/M1 = -(2.5+-0.2+-0.2)% at the maximum of the Delta(1232) resonance has been derived.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: MacGregor, Professor Douglas and Kellie, Dr James
• Authors: Beck, R., Krahn, H.P., Ahrens, J., Arends, H.J., Audit, G., Braghieri, A., dHose, N., Hall, S.J., Isbert, V., Kellie, J.D., MacGregor, I.J.D., Pedroni, P., Pinelli, T., Tamas, G., Walcher, T., and Wartenberg, S.
• Subjects: Q Science > QC Physics
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Research Group: Nuclear Physics
• Journal Name: Physical Review Letters
• Journal Abbr.: Phys. Rev. Lett.
• Publisher: American Physical Society
• ISSN: 0031-9007
• ISSN (Online): 1079-7114