October 2018

Journal

Status of the NPDGamma experiment

By:
Baessler, Stefan F; Alarcon, Ricardo O; Bowman, James D; Craycraft, Kayla L; Penttila, Seppo I; Pocanic, Dinko ; Allen, Richard R; Crawford, C.; Fomin, Nadia; Blessinger, Christopher S; Gillis, Robert C; Iverson, Erik B; Mueller, Paul E; Thomison Jr, Jack B
Journal Name:
Hyperfine Interactions
Page Number:
11
Volume:
238
Issue Number:
1
Publication Date:
October 25, 2018
View DOI Listing:
https://doi.org/10.1007/s10751-016-1376-4

Abstract

The NPDGamma experiment measures the parity-violating (PV) gamma asymmetry from polarized cold neutrons captured on protons at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL). The (PV) neutron spin asymmetry A γ of photons from polarized cold neutron capture on protons is proportional to the ΔI=1 long range weak meson coupling h1π between nucleons in the hadronic weak interaction (HWI). Liquid para-hydrogen production data taking concluded in April 2014 and once the background aluminum asymmetry measurements are complete, the PV asymmetry A γ can be extracted. Preliminary results of the analysis of A γ are presented.