Polarized-target asymmetry in pion-proton bremsstrahlung at 298 MeV

Journal Article · Mon May 28 04:00:00 EDT 1990 · Physical Review Letters; (USA)

DOI:https://doi.org/10.1103/PhysRevLett.64.2619· OSTI ID:6940920

Bosshard, A; Amsler, C; Bistirlich, J A; van den Brandt, B; Crowe, K M; Doebeli, M; Doser, M; Haddock, R P; Konter, J A; Ljungfelt, S; Loude, J F; Mango, S; Meyer, C A; Perroud, J P; Riedlberger, J; Renker, D; Schaad, M; Sober, D I; Truoel, P; Weymuth, P ^[1]

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1. Physik Institut der Universitaet Zuerich; 8001 Zuerich; (Switzerland) Lawrence Berkeley Laboratory; University of California at Berkeley; Berkeley California 94720 Paul Scherrer Institut; 5232 Villigen; Paul Scherrer Institut; (Switzerland) Department of Physics; University of California at Los Angeles; Los Angeles; California 90024 (USA) Institut de Physique Nucleaire; Universite de Lausanne; 1015 Lausanne; (Switzerland) Department of Physics; Catholic University of America; Washington; D.C. 10024 (USA)

First data are presented for the polarized-target asymmetry in the reaction {pi}{sup +}{ital p}{r arrow}{pi}{sup +}{ital p}{gamma} at an incident pion energy of 298 MeV. The geometry was chosen to maximize the sensitivity to the radiation of the magnetic dipole moment {mu}{sub {Delta}} of the {Delta}{sup ++}(1232 MeV). A fit of the asymmetry in the cross section {ital d}{sup 5}{sigma}/{ital d}{Omega}{sub {pi}} {ital d}{Omega}{sub {gamma}} {ital dk} as a function of the photon energy {ital k} to predictions from a recent isobar-model calculation with {mu}{sub {Delta}} as the only free parameter yields {mu}{sub {Delta}}=1.64({plus minus}0.19exp{Delta},{plus minus}0.14 theor){mu}{sub {ital p}}. Though this value agrees with bag-model corrections to the SU(6) prediction {mu}{sub {Delta}}=2{mu}{sub {ital p}}, further clarifications on the model dependence of the result are needed, in particular since the isobar model fails to describe both the cross section and the asymmetry at the highest photon energies.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 6940920
• Journal Information: Physical Review Letters; (USA), Journal Name: Physical Review Letters; (USA) Vol. 64:22; ISSN 0031-9007; ISSN PRLTA
• Country of Publication: United States
• Language: English

Related Subjects

645103* -- High Energy Physics-- Particle Interactions & Properties-Experimental-- Strong Interactions & Baryon & Meson Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANGULAR DISTRIBUTION
ASYMMETRY
BREMSSTRAHLUNG
COMPOSITE MODELS
DATA
DISTRIBUTION
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
ENERGY RANGE
EXPERIMENTAL DATA
HADRON-HADRON INTERACTIONS
INELASTIC SCATTERING
INFORMATION
INTERACTIONS
MASSLESS PARTICLES
MATHEMATICAL MODELS
MESON-BARYON INTERACTIONS
MESON-NUCLEON INTERACTIONS
MEV RANGE
MEV RANGE 100-1000
NUMERICAL DATA
PARTICLE IDENTIFICATION
PARTICLE INTERACTIONS
PARTICLE KINEMATICS
PARTICLE MODELS
PARTICLE PRODUCTION
PHOTONS
PION PLUS-PROTON INTERACTIONS
PION-NUCLEON INTERACTIONS
PION-PROTON INTERACTIONS
POLARIZED TARGETS
QUARK MODEL
RADIATIONS
SCATTERING
TARGETS