Direct determination of neutron lifetime in $\beta$-decay

Abstract

The neutron lifetime is determined for now most accurately by two methods --the so-called "beam method" and the method of neutron storage in a trap. The goal of this research is to obtain the neutron lifetime with a higher precision by eliminating the traditional systematic errors. A new feature is extracting the neutron lifetime only from the set of electron counting rates with their errors. The newly received neutron lifetime value is $$ \tau_{NT}=883.31\pm0.02(stat.)\pm0.02(sys.) \quad \mbox{s.} $$ The obtained neutron lifetime is the weighted average of two lifetimes, defined for different subsets of neutrons providing the well-known effect of the asymmetry in the neutron $\beta$-decay. Simple calculations predict the values of these lifetimes and show their correspondence to the known asymmetry parameters of neutron decay. The arithmetic mean (central) value for the two newly introduced neutron lifetimes was determined. The resulting weighted value $\tau_{NT}$ is in a good agreement with the lifetimes in the first and second methods in limits of their double errors, but exceeds them significantly in precision. In addition, estimates of the new lifetimes, which are called here as $L$-neutron lifetime and $R$-neutron lifetime, are fulfilled. The estimation results correspond to the known parameters of the neutron decay asymmetry. \keywords{neutron \and decay \and channel \and lifetime \and electron \and trap} \PACS{06.30.-k \and 12.90+b \and 13.30Ce \and 14.20.Dh \and 28.20-V \and 29.40 Cs}