Measurement of the parity-violating triton emission asymmetry in the reaction 6Li(n,alfa)3H with polarised cold neutrons

TL;DR

This study measures the parity-violating asymmetry in the 6Li(n,alpha)3H reaction using polarized cold neutrons, achieving high suppression of false signals and providing a precise value for the P-odd effect.

Contribution

First precise measurement of the parity-violating asymmetry in the 6Li(n,alpha)3H reaction with advanced suppression techniques.

Findings

Measured P-odd asymmetry: (-8.6±2.0)×10^(-8)

Zero test confirmed negligible false asymmetry

High suppression of left-right asymmetry below 10^(-8)

Abstract

We describe measurements of the parity-violating (P-odd) triton emission asymmetry coefficient in the 6Li(n,alfa)3H reaction with polarised cold neutrons. Experiments were carried out at the Petersburg Nuclear Physics Institute (Gatchina, Russia) and at the Institut Laue-Langevin (Grenoble, France). We employed an ionisation chamber in a configuration allowing us to suppress the left-right asymmetry well below 10^(-8). A test for a false asymmetry due to eventual target impurities ("zero test") resulted in the value (0.0+-0.5)x10^(-8). As final result we obtained P-odd effect (-8.6+-2.0)x10^(-8).