An update on the NPDGamma experiment

ORAL

Abstract

The NPDGamma experiment recently finished collecting roughly two-hundred fifty beam days of data measuring parity violation in the $np\rightarrow d\gamma$ reaction at the ORNL Spallation Neutron Source. The parity-violating directional asymmetry in the emission of prompt gammas from the capture of polarized cold neutrons on a liquid hydrogen target provides a measurement of the NN hadronic weak interaction that is unambiguously related to benchmark DDH model parameters (primarily $h_\pi^1$) and PV EFT couplings. An overview of the experiment and data selection/reduction challenges will be presented along with an initial low-statistics result. Projected uncertainties in the final result will be discussed taking into account the entirety of beam time at the FNPB dedicated to both hydrogen and background capture measurements.

Authors

  • David Blyth

    Arizona State University