Measurement of the {ital E}2/{ital M}1 Ratio in the {ital N{r_arrow}{Delta}} Transition using the reaction {ital p}({gamma} {searrow},{ital p}) {pi}{sup {ital o}}

Journal Article · Wed Jan 01 00:00:00 EST 1997 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.78.606· OSTI ID:439097

Beck, R; Krahn, H; Ahrens, J; Arends, H; Isbert, V; Walcher, T; Wartenberg, S ^[1]; Audit, G; dHose, N; Tamas, G ^[2]; Braghieri, A; Pedroni, P; Pinelli, T ^[3]; Hall, S; Kellie, J; MacGregor, I ^[4]

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1. Institut fuer Kernphysik, Universitaet Mainz, 55099 Mainz (Germany)
2. Service de Physique Nucleaire-Departement d`Astrophysique, Physique des Particules, Physique Nucleaire et d`Instrumentation Assocciee, CE. Saclay, 91191 Gif-sur-Yvette (France)
3. Istituto Nazionale di Fisica Nucleare, Sezione di Pavia, 27100 Pavia (Italy)
4. Department of Physics and Astronomy, Glasgow University, Glasgow G12 8QQ (United Kingdom)

The small electric quadrupole E2 amplitude of the predominantly magnetic dipole M1 p{r_arrow}{Delta}(1232) transition has been measured using 270 to 420MeV tagged linearly polarized photons in the p({gamma}{searrow},p){pi}{sup o} reaction at the Mainz Microtron MAMI. Differential cross sections and photon asymmetries were determined by measuring the recoil proton in the cylindrically symmetric 4{pi} detector DAPHNE. From the proton angular distributions the ratio E2/M1=-(2.5{plus_minus}0.2{plus_minus}0.2){percent} at the maximum of the {Delta}(1232) resonance has been derived. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 439097
• Journal Information: Physical Review Letters, Vol. 78, Issue 4; Other Information: PBD: Jan 1997
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
PHOTON-PROTON INTERACTIONS
POLARIZED BEAMS
PROTONS
E2-TRANSITIONS
M1-TRANSITIONS
DELTA-1232 BARYONS
PIONS NEUTRAL
DIFFERENTIAL CROSS SECTIONS
ASYMMETRY
ANGULAR DISTRIBUTION