Experimental Upper Bound and Theoretical Expectations for Parity-Violating Neutron Spin Rotation in 4He
| Autor: | M. Sarsour, Jeffrey S. Nico, S. B. Walbridge, E. I. Sharapov, Hans P. Mumm, T. D. Bass, D. M. Markoff, J. C. Horton, H. E. Swanson, A. M. Micherdzinska, C.R. Huffer, D. Luo, C.D. Bass, Bret E. Crawford, J. M. Dawkins, V. Zhumabekova, K. Gan, W. M. Snow, Blayne Heckel |
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| Rok vydání: | 2019 |
| Předmět: |
Quantum chromodynamics
Physics Particle physics 010308 nuclear & particles physics Nuclear Theory FOS: Physical sciences Parity (physics) Weak interaction 01 natural sciences Upper and lower bounds Article Amplitude 0103 physical sciences Neutron High Energy Physics::Experiment Analysis tools Nuclear Experiment (nucl-ex) 010306 general physics Nucleon Nuclear Experiment |
| Zdroj: | Physical review. C |
| DOI: | 10.48550/arxiv.1902.08026 |
| Popis: | Neutron spin rotation is expected from quark-quark weak interactions in the Standard Model, which induce weak interactions among nucleons that violate parity. We present the results from an experiment searching for the effect of parity violation via the spin rotation of polarized neutrons in a liquid $^{4}$He medium. The value for the neutron spin rotation angle per unit length in $^{4}$He, $d\phi/dz =(+2.1 \pm 8.3 (stat.) \pm 2.9 (sys.))\times10^{-7}$ rad/m, is consistent with zero. The result agrees with the best current theoretical estimates of the size of nucleon-nucleon weak amplitudes from other experiments and with the expectations from recent theoretical approaches to weak nucleon-nucleon interactions. In this paper we review the theoretical status of parity violation in the $\vec{n}+^{4}$He system and discuss details of the data analysis leading to the quoted result. Analysis tools are presented that quantify systematic uncertainties in this measurement and that are expected to be essential for future measurements. Comment: 15 pages, 7 figures |
| Databáze: | OpenAIRE |
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