Measurement of the weak nucleon-nucleon interaction by polarized cold neutron capture on protons
1 Department of Physics, Arizona State University, Tempe, AZ 85287-1504, USA
Published online: 20 March 2014
The NPDGamma Experiment at the Spallation Neutron Source at Oak Ridge National Laboratory is measuring the parity-odd correlation between the neutron spin and the direction of the emitted photon in the capture of polarized cold neutrons on protons. A parity violating asymmetry from this process is directly related to the strength of the hadronic weak interaction between nucleons. The experiment was run first with heavier nuclear targets to check systematic effects, false asymmetries, and backgrounds. Since early 2012 the experiment has been collecting data with a 16-liter liquid parahydrogen target. Data taking will continue through 2013 until statistics for a 10−8 asymmetry measurement are expected. The experiment performance will be discussed as well as the status of the asymmetry measurements.
Arizona State University, Bhabha Atomic Research Centre, Hamilton College, Indiana University, Joint Institute of Nuclear Research, High Energy Accelerator Research Org. (KEK), University of Kentucky, Los Alamos National Laboratory, University of Manitoba, University of Michigan, University of Nevada Las Vegas, University of New Hampshire, Oak Ridge National Laboratory, Paul Scherrer Institute, Shanghai Institute of Applied Physics, University of Tennessee, University of Tennessee Chattanooga, Universidad Autónoma de México, TRIUMF, University of Virginia, Western Kentucky University
© Owned by the authors, published by EDP Sciences, 2014