Hans Pieter Mumm

Dr. H. Pieter Mumm is a physicist and leader of the Neutron Physics Group at the National Institute of Standards and Technology. His research tests the foundations of the Standard Model through precision neutron measurements, including tests of time-reversal invariance that probe the matter-antimatter asymmetry of the universe, the first observation of neutron radiative decay, and precision neutron lifetime measurements using novel trapping methods. He currently co-leads a beam-based neutron lifetime measurement counting decay protons from a cold neutron beam with a precisely determined flux. His metrology work includes precise neutron source calibrations using a manganese bath and development of fast neutron detectors for applications from source calibration to neutron spectroscopy. As co-spokesperson for the PROSPECT experiment, Dr. Mumm helped perform high-precision measurements of reactor antineutrinos, playing a significant role in addressing anomalies hinting at the existence of sterile neutrinos. Dr. Mumm holds a Ph.D. from the University of Washington.

Title: Sterile neutrino search with PROSPECT at the High Flux Isotope Reactor

Abstract: The Precision Reactor Oscillation and SPECTrum (PROSPECT) experiment was designed to investigate unexpected discrepancies between predicted and observed neutrino output of a nuclear reactor which were thought to be intriguing hints at new physics.  PROSPECT overcame significant technical challenges to carry out a first-of-kind data collection run in 2018 at the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory, observing more than 50,000 neutrino interactions in the detector.  These data have subsequently been used to set strong limits on the possible existence of a new ‘sterile’ neutrino.  This talk will describe the successful design and physics program of PROSPECT and its impact on our current understanding of reactor neutrinos.