Physicists seek neutron lifetime’s secret

New experiments aim to pin down subatomic particle’s decay rate

NIST Center for Neutron Research

TIME’S UP  New experiments aim to resolve a puzzle about how long the neutron takes to decay. At the National Institute of Standards and Technology’s Center for Neutron Research (shown), physicists will monitor a beam of neutrons to determine the neutron’s lifetime.

Ronald Cappelletti/NIST

WASHINGTON — Lone neutrons quickly decay, but scientists don’t agree on how long the particles stick around before their demise.