Tensor interaction limit derived from the α-β-ν[over ¯] correlation in trapped 8Li ions

Area of Science:

• Nuclear Physics
• Particle Physics
• Standard Model Tests

Background:

• The Standard Model (SM) of particle physics describes fundamental forces and particles.
• Beta decay processes offer a sensitive probe for testing SM predictions and searching for new physics beyond the SM.
• Previous measurements of beta-neutrino correlations have provided constraints on electroweak interaction components.

Purpose of the Study:

• To precisely measure the alpha-beta-neutrino angular correlation in the Gamow-Teller decay of Lithium-8.
• To constrain the contribution of tensor interactions to the electroweak force.
• To compare experimental results with Standard Model predictions and explore potential deviations.

Main Methods:

• Ions of Lithium-8 were confined in a linear Paul trap.
• Emitted alpha particles were detected using surrounding silicon detectors.
• The energy difference spectrum of alpha particles was analyzed to determine angular correlations.

Main Results:

• The measured alpha-beta-neutrino angular correlation is consistent with the Standard Model prediction.
• A limit of 3.1% (95.5% confidence level) was placed on any tensor contribution to the decay.
• The amplitude of any tensor component relative to the axial-vector component was limited to |C(T)/C(A)| < 0.18 (95.5% confidence level).

Conclusions:

• The experiment provides stringent constraints on tensor contributions in electroweak interactions.
• The Lithium-8 beta decay serves as a valuable system for precise measurements of fundamental interactions.
• This approach offers complementary systematic effects compared to previous studies using Helium-6 beta decay.