Precise neutron lifetime experiment using pulsed neutron beams at J-PARC

TL;DR

This paper reports on a new neutron lifetime measurement experiment at J-PARC aiming for 0.1% precision, detailing the setup, initial data, and future plans to improve accuracy.

Contribution

The paper introduces a novel experimental setup for neutron lifetime measurement using pulsed neutron beams at J-PARC, achieving initial data collection and outlining steps toward higher precision.

Findings

Initial data acquired in 2014-2015

First lifetime evaluation in 2016

Expected statistical uncertainty of about 1%

Abstract

The neutron lifetime is one of the basic parameters in the weak interaction, and is used for predicting the light element abundance in the early universe. Our group developed a new setup to measure the lifetime with the goal precision of 0.1% at the polarized beam branch BL05 of MLF, J-PARC. The commissioning data was acquired in 2014 and 2015, and the first set of data to evaluate the lifetime in 2016, which is expected to yield a statistical uncertainty of O(1)%. This paper presents the current analysis results and the future plans to achieve our goal precision.