| Autor: |
M T, Gericke, S, Baeßler, L, Barrón-Palos, N, Birge, J D, Bowman, J, Calarco, V, Cianciolo, C E, Coppola, C B, Crawford, N, Fomin, I, Garishvili, G L, Greene, G M, Hale, J, Hamblen, C, Hayes, E, Iverson, M L, Kabir, M, McCrea, E, Plemons, A, Ramírez-Morales, P E, Mueller, I, Novikov, S, Penttila, E M, Scott, J, Watts, C, Wickersham |
| Rok vydání: |
2020 |
| Zdroj: |
Physical review letters. 125(13) |
| ISSN: |
1079-7114 |
| Popis: |
We report the first precision measurement of the parity-violating asymmetry in the direction of proton momentum with respect to the neutron spin, in the reaction ^{3}He(n,p)^{3}H, using the capture of polarized cold neutrons in an unpolarized active ^{3}He target. The asymmetry is a result of the weak interaction between nucleons, which remains one of the least well-understood aspects of electroweak theory. The measurement provides an important benchmark for modern effective field theory and potential model calculations. Measurements like this are necessary to determine the spin-isospin structure of the hadronic weak interaction. Our asymmetry result is A_{PV}=[1.55±0.97(stat)±0.24(sys)]×10^{-8}, which has the smallest uncertainty of any hadronic parity-violating asymmetry measurement so far. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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