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Sharpening low-energy, standard-model tests via correlation coefficients in neutron beta decay
1Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055, USA. gardner@pa.uky.edu
Physical Review Letters
|June 21, 2001
Summary
New neutron decay experiments will precisely measure coupling constants, enabling tests of the Standard Model and searches for exotic physics like second-class currents. These studies promise improved bounds on fundamental symmetries in nuclear beta decay.
Area of Science:
- Nuclear Physics
- Particle Physics
- Standard Model Physics
Background:
- Neutron beta decay provides a sensitive probe of fundamental interactions.
- The ratio of axial-vector-to-vector weak coupling constants (gA/gV) is a key parameter.
- Recoil-order corrections to correlation coefficients are becoming experimentally accessible.
Purpose of the Study:
- To explore the potential of next-generation neutron decay experiments.
- To investigate the experimental accessibility of recoil-order corrections.
- To enable precise tests of the Standard Model and fundamental symmetries.
Main Methods:
- Analysis of neutron beta decay correlation coefficients (a, A, B).
- Focus on the proportionality to the gA/gV ratio at leading recoil order.
- Utilizing high-precision measurements from upcoming experiments.
Main Results:
- Recoil-order corrections to neutron decay observables are experimentally accessible.
- Measurements of 'a' and 'A' allow independent tests of the conserved-vector-current (CVC) hypothesis.
- Potential for improved bounds on CVC violation and second-class currents (SCC).
Conclusions:
- Next-generation neutron decay experiments offer significant opportunities for Standard Model tests.
- Precise measurements can provide qualitatively better constraints on fundamental physics beyond leading order.
- This research advances the search for new physics in nuclear beta decay.
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