Measurement of the doubly-polarized He3→(γ→,n)pp reaction at 16.5 MeV and its implications for the GDH sum rule

G. Laskaris; X. Yan; J.M. Mueller; W.R. Zimmerman; W. Xiong; M.W. Ahmed; T. Averett; P.-H. Chu; A. Deltuva; C. Flower; A.C. Fonseca; H. Gao; J. Golak; J.N. Heideman; H.J. Karwowski; M. Meziane; P.U. Sauer; R. Skibiński; I.I. Strakovsky; H.R. Weller; H. Witała; Y.K. Wu

doi:10.1016/j.physletb.2015.09.065

Physics Letters B (Nov 2015)

Measurement of the doubly-polarized He3→(γ→,n)pp reaction at 16.5 MeV and its implications for the GDH sum rule

G. Laskaris,
X. Yan,
J.M. Mueller,
W.R. Zimmerman,
W. Xiong,
M.W. Ahmed,
T. Averett,
P.-H. Chu,
A. Deltuva,
C. Flower,
A.C. Fonseca,
H. Gao,
J. Golak,
J.N. Heideman,
H.J. Karwowski,
M. Meziane,
P.U. Sauer,
R. Skibiński,
I.I. Strakovsky,
H.R. Weller,
H. Witała,
Y.K. Wu

Affiliations

G. Laskaris: Triangle Universities Nuclear Laboratory, Durham, NC 27708, USA
X. Yan: Triangle Universities Nuclear Laboratory, Durham, NC 27708, USA
J.M. Mueller: Triangle Universities Nuclear Laboratory, Durham, NC 27708, USA
W.R. Zimmerman: Triangle Universities Nuclear Laboratory, Durham, NC 27708, USA
W. Xiong: Triangle Universities Nuclear Laboratory, Durham, NC 27708, USA
M.W. Ahmed: Triangle Universities Nuclear Laboratory, Durham, NC 27708, USA
T. Averett: College of William and Mary, Williamsburg, VA 23187, USA
P.-H. Chu: Triangle Universities Nuclear Laboratory, Durham, NC 27708, USA
A. Deltuva: Institute of Theoretical Physics and Astronomy, Vilnius University, LT-01108 Vilnius, Lithuania
C. Flower: Triangle Universities Nuclear Laboratory, Durham, NC 27708, USA
A.C. Fonseca: Centro de Física Nuclear da Universidade de Lisboa, P-1649-003 Lisboa, Portugal
H. Gao: Triangle Universities Nuclear Laboratory, Durham, NC 27708, USA
J. Golak: M. Smoluchowski Institute of Physics, Jagiellonian University, PL-30348 Kraków, Poland
J.N. Heideman: Triangle Universities Nuclear Laboratory, Durham, NC 27708, USA
H.J. Karwowski: Triangle Universities Nuclear Laboratory, Durham, NC 27708, USA
M. Meziane: Triangle Universities Nuclear Laboratory, Durham, NC 27708, USA
P.U. Sauer: Institut für Theoretische Physik, Leibniz Universität Hannover, D-30167 Hannover, Germany
R. Skibiński: M. Smoluchowski Institute of Physics, Jagiellonian University, PL-30348 Kraków, Poland
I.I. Strakovsky: Department of Physics, The George Washington University, Washington, DC 20052, USA
H.R. Weller: Triangle Universities Nuclear Laboratory, Durham, NC 27708, USA
H. Witała: M. Smoluchowski Institute of Physics, Jagiellonian University, PL-30348 Kraków, Poland
Y.K. Wu: Triangle Universities Nuclear Laboratory, Durham, NC 27708, USA

DOI: https://doi.org/10.1016/j.physletb.2015.09.065
Journal volume & issue: Vol. 750, no. C
pp. 547 – 551

Abstract

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We report new measurements of the double-polarized photodisintegration of 3He at an incident photon energy of 16.5 MeV, carried out at the High Intensity γ-ray Source (HIγS) facility located at Triangle Universities Nuclear Laboratory (TUNL). The spin-dependent double-differential cross sections and the contribution from the three-body channel to the Gerasimov–Drell–Hearn (GDH) integrand were extracted and compared with the state-of-the-art three-body calculations. The calculations, which include the Coulomb interaction and are in good agreement with the results of previous measurements at 12.8 and 14.7 MeV, deviate from the new cross section results at 16.5 MeV. The GDH integrand was found to be about one standard deviation larger than the maximum value predicted by the theories.

Published in Physics Letters B

ISSN: 0370-2693 (Print); 1873-2445 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Science: Physics
Website: http://www.journals.elsevier.com/physics-letters-b/

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