High-Precision Half-Life Measurements for the Superallowed β^{+} Emitter ^{10}C: Implications for Weak Scalar...

Area of Science:

• Nuclear Physics
• Particle Physics
• Fundamental Interactions

Background:

• Superallowed Fermi β-decay transitions are crucial for testing the Standard Model of particle physics.
• Previous measurements of the carbon-10 (¹⁰C) half-life showed discrepancies, necessitating precise re-evaluation.

Purpose of the Study:

• To resolve discrepancies in recent ¹⁰C half-life measurements.
• To provide highly precise half-life data for ¹⁰C to constrain scalar current contributions to the weak interaction.

Main Methods:

• Performed two high-precision half-life measurements for ¹⁰C using γ-ray photopeak and β counting.
• Analyzed world superallowed β-decay data, incorporating the new ¹⁰C measurements.

Main Results:

• Obtained consistent and highly precise values for the ¹⁰C half-life: 19.2969±0.0074 s and 19.3009±0.0017 s.
• Achieved a relative precision below 10⁻⁴ for the ¹⁰C half-life, representing a significant advancement.
• The Fierz interference term (bF) was determined to be -0.0018±0.0021, and the ratio of weak scalar to vector couplings (CS/CV) was found to be +0.0009±0.0011.

Conclusions:

• The new precise measurements of the ¹⁰C half-life resolve previous discrepancies.
• The results provide stringent limits on scalar current contributions to the weak interaction, consistent with the absence of new physics beyond the Standard Model.