Precision Measurement of Radiative Neutron Decay.

Abstract

The theory of quantum electrodynamics (QED) predicts that a neutron's decay into a proton, electron, and anti-neutrino will be accompanied by a radiative photon spectrum. While neutron decay is a prototypical example of weak decay, detection of its radiative photons has been difficult to measure due to strong sources of background photons related to neutron capture and neutron production. By the simultaneous detection of a prompt photon and electron followed by a delayed proton, the RDK II experiment was able to reliably identify radiative neutron decays relative to non-radiative decays in the photon energy range of approximately 0.5 keV to the 782 keV endpoint. RDK II serves as not only a test of QED but as a stepping stone towards an improved measurement of radiative neutron decay, which could test quantum chromodynamics and beyond the Standard Model theories.

In this dissertation, the relevant theory is introduced first, followed by a detailed description of the RDK II experimental apparatus. The author's primary contribution to the experiment, a monte carlo simulation of the apparatus, is then discussed. Next, a preliminary analysis of the experimental data is compared to the simulated data. This comparison shows good agreement between the two data sets across many relevant experimental parameters. Finally, future experiments and analysis related to RDK II are examined.