First Precision Measurement of the Parity Violating Asymmetry in Cold Neutron Capture on
Phys Rev Lett
; 125(13): 131803, 2020 Sep 25.
Article
em En
| MEDLINE
| ID: mdl-33034491
ABSTRACT
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.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Phys Rev Lett
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Canadá