Schmidt A, Achenbach P, Ahrens J, Arends HJ, Beck R, Bernstein AM, Hejny V, Kotulla M, Krusche B, Kuhr V, Leukel R, MacGregor IJ, McGeorge JC, Metag V, Olmos De León VM, Rambo F, Siodlaczek U, Ströher H, Walcher T, Weiss J, Wissmann F, Wolf M. Test of low-energy theorems for 1H(--> gamma, pi(0))(H)in the threshold hegion.
Phys Rev Lett 2001;
87:232501. [PMID:
11736448 DOI:
10.1103/physrevlett.87.232501]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2001] [Indexed: 05/23/2023]
Abstract
The photon asymmetry in the reaction 1H(--> gamma,pi(0))(1)H close to threshold has been measured for the first time with the photon spectrometer TAPS using linearly polarized photons from the tagged-photon facility at the Mainz Microtron MAMI. The total and differential cross sections were also measured simultaneously with the photon asymmetry. This allowed determination of the S-wave and all three P-wave amplitudes. The values obtained at threshold are E(0+) = [-1.33+/-0.08(stat)+/-0.03(syst)] x 10(-3)/m(pi(+)), P(1) = [9.47 +/- 0.08(stat) +/- 0.29(syst)] x 10(-3)q/m(2)(pi(+)), P(2) = [-9.46 +/- 0.1(stat) +/- 0.29(syst)] x 10(-3)q/m(2)(pi(+)), and P(3) = [11.48 +/- 0.06(stat) +/- 0.35(syst)] x 10(-3)q/m(2)(pi(+)).
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