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arXiv · 0712.2442

Measurement of the Proton Asymmetry Parameter C in Neutron Beta Decay

M. Schumann·M. Kreuz·M. Deissenroth·F. Glueck·J. Krempel·B. Maerkisch·D. Mund·A. Petoukhov·T. Soldner·H. Abele
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Abstract

The proton asymmetry parameter C in neutron decay describes the correlation between neutron spin and proton momentum. In this Letter, the first measurement of this quantity is presented. The result C=-0.2377(26) agrees with the Standard Model expectation. The coefficient C provides an additional parameter for new and improved Standard Model tests. From a differential analysis of the same data (assuming the Standard Model), we obtain lambda=-1.275(16) as ratio of axial-vector and vector coupling constant.

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M. Schumann, M. Kreuz, M. Deissenroth, F. Glueck, J. Krempel, B. Maerkisch, D. Mund, A. Petoukhov, T. Soldner, H. Abele. 2007-12-14. Measurement of the Proton Asymmetry Parameter C in Neutron Beta Decay. https://doi.org/10.1103/physrevlett.100.151801

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