Physicists seek neutron lifetime’s secret | Science News


Science News is a nonprofit.

Support us by subscribing now.


Physicists seek neutron lifetime’s secret

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

9:34am, February 1, 2017
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.

WASHINGTON — Lone neutrons quickly decay, but scientists don’t agree on how long the particles stick around before their demise. New experiments could resolve the dispute — or deepen the mystery.

Outside of a nucleus, neutrons survive only about 15 minutes on average. They quickly decay into a proton, an electron and an antineutrino. Two methods used for measuring the neutron lifetime disagree, leaving scientists uncertain about the subatomic particle’s true longevity (SN: 5/19/12, p. 20).

One technique involves containing chilled neutrons in a trap, or “bottle,” waiting awhile, and counting the remaining neutrons to determine how many decayed. Other experiments monitor beams of neutrons and count the number of decays by detecting the protons emitted. Bottle measurements come up with lifetimes about 9 seconds

This article is only available to Science News subscribers. Already a subscriber? Log in now.
Or subscribe today for full access.

Get Science News headlines by e-mail.

More from Science News

From the Nature Index Paid Content