English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

The Ultracold Neutron Asymmetry (UCNA) experiment was designed to measure the$\beta$-decay asymmetry parameter, $A_0$, for free neutron decay. In theexperiment, polarized ultracold neutrons are transported into a decay trap, andtheir $\beta$-decay electrons are detected with $\approx 4\pi$ acceptance intotwo detector packages which provide position and energy reconstruction. Theexperiment also has sensitivity to $b_{n}$, the Fierz interference term in theneutron $\beta$-decay rate. In this work, we determine $b_{n}$ from the energydependence of $A_0$ using the data taken during the UCNA 2011-2013 run. Inaddition, we present the same type of analysis using the earlier 2010 $A$dataset. Motivated by improved statistics and comparable systematic errorscompared to the 2010 data-taking run, we present a new $b_{n}$ measurementusing the weighted average of our asymmetry dataset fits, to obtain $b_{n} =0.066 \pm 0.041_{\text{stat}} \pm 0.024_{\text{syst}}$ which corresponds to alimit of $-0.012 < b_{n} < 0.144$ at the 90% confidence level.

Improved limits on Fierz Interference using asymmetry measurements from the UCNA experiment