Improved Limit on Tensor Currents in the Weak Interaction from ^{8}Li β Decay.

Area of Science:

• Particle Physics
• Nuclear Physics
• Standard Model

Background:

• The Standard Model describes electroweak interactions with a vector-axial-vector structure.
• Lorentz-invariant components can also contribute to electroweak interactions.

Purpose of the Study:

• To provide the most precise measurement of tensor currents in the low-energy regime.
• To examine the beta-neutrino correlation in trapped Lithium-8 ions.

Main Methods:

• Utilized the Beta-decay Paul Trap for ion trapping.
• Measured the beta-neutrino correlation of trapped Lithium-8 ions.

Main Results:

• Determined the beta-neutrino correlation coefficient a_{βν} = -0.3325 ± 0.0013 (stat) ± 0.0019 (syst).
• This measurement is consistent with the Standard Model prediction for coupling to right-handed neutrinos (C_{T}=-C_{T}^{'}).

Conclusions:

• The findings support the Standard Model's description of electroweak interactions.
• The precise measurement of tensor currents provides stringent tests of fundamental physics.