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arXiv · 2306.15042

Recoil-Order and Radiative Corrections to the aCORN Experiment

F. E. Wietfeldt·W. A. Byron·B. Collett·M. S. Dewey·T. R. Gentile·F. Gluck·M. T. Hassan·G. L. Jones·A. Komives·J. S. Nico·E. J. Stephenson
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Abstract

The aCORN experiment measures the electron-antineutrino $a$-coefficient in free neutron decay. We update the previous aCORN results to include radiative and recoil corrections to first order, and discuss a key issue in the comparison of results from different $a$-coefficient experimental methods when these effects are considered. The corrected combined result is $\overline{a} = -0.10779 \pm 0.00125\, ({\rm stat}) \pm 0.00133\, ({\rm sys})$, averaged over the full Fermi neutron beta spectrum. The corresponding corrected result for the ratio of weak coupling constants $\lambda = G_A/G_V$ is $\lambda = -1.2712 \pm 0.0061$. This improves agreement with previous $a$-coefficient experiments, in particular the 2020 aSPECT result

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F. E. Wietfeldt, W. A. Byron, B. Collett, M. S. Dewey, T. R. Gentile, F. Gluck, M. T. Hassan, G. L. Jones, A. Komives, J. S. Nico, E. J. Stephenson. 2023-06-26. Recoil-Order and Radiative Corrections to the aCORN Experiment. https://arxiv.org/abs/2306.15042

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