Just how long does a neutron live? Physics Professor Geoff Greene is among the scientists looking to solve this mystery and explained its importance to in this U.S. Department of Energy feature: "The Mystery of the Neutron Lifetime."
As the story points out:
Nuclear physicists first started studying the neutron lifetime because of its essential role in physics. "There are some fundamental quantities in nature that seem to be always important," said Geoff Greene, University of Tennessee professor and physicist at DOE’s Oak Ridge National Laboratory. He’s been researching the neutron lifetime for much of his lifetime – about 40 years. "Theories come and go, but the neutron lifetime seems to remain a central parameter in a variety of things."
Greene's pursuit of this question has been featured earlier in Scientific American.