First Measurement of the Gerasimov-Drell-Hearn Integral for H

Journal Article · Mon Jul 09 04:00:00 EDT 2001 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.87.022003· OSTI ID:40276953

Ahrens, J; Altieri, S; Annand, J R. M.; Anton, G; Arends, H -J; Aulenbacher, K; Beck, R; Bradtke, C; Braghieri, A; Degrande, N ^[1]

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1. and others

A direct measurement of the helicity dependence of the total photoabsorption cross section on the proton was carried out at MAMI (Mainz) in the energy range 200<E{sub {gamma}}<800 MeV . The experiment used a 4{pi} detection system, a circularly polarized tagged photon beam, and a frozen spin target. The contributions to the Gerasimov-Drell-Hearn sum rule and to the forward spin polarizability {gamma}{sub 0} determined from the data are 226{+-}5(stat){+-}12(syst) {mu}b and -187{+-}8(stat){+-}10(syst) x 10{sup -6} fm{sup 4} , respectively, for 200<E{sub {gamma}}<800 MeV .

• Sponsoring Organization: (US)
• OSTI ID: 40276953
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 2 Vol. 87; ISSN 0031-9007
• Publisher: The American Physical Society
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CROSS SECTIONS
DETECTION
ENERGY RANGE
HELICITY
PHOTON BEAMS
POLARIZABILITY
PROTONS
SPIN
SUM RULES