müon

Muon

A muon is an elementary subatomic particle classified as a lepton, similar to the electron but with a significantly greater mass. Discovered in 1936 by Carl Anderson and Seth Neddermeyer during cosmic ray experiments, muons are produced naturally when high-energy cosmic rays collide with atoms in the Earth's atmosphere. They are unstable particles with an average lifespan of approximately 2.2 microseconds, during which they decay into electrons, neutrinos, and antineutrinos.

Muons have a negative electric charge, identical in magnitude to that of electrons, but are about 200 times heavier. Due to their high mass, muons can penetrate materials more deeply than electrons, making them useful in various scientific and industrial applications. For example, muon tomography exploits their penetrating ability to image the interior of large or dense objects, such as geological formations, archaeological sites, and nuclear reactors.

In particle physics, muons are studied extensively within high-energy accelerators, where they serve as probes to investigate fundamental forces and particles. Despite their relatively short lifespan, muons have been instrumental in testing the Standard Model of particle physics and contributed to the discovery of phenomena such as lepton universality.

Muon properties include a rest mass of about 105.7 MeV/c² and a magnetic moment close to that of a free electron, with slight deviations that are of interest in precision tests of fundamental physics. Muons do not experience strong nuclear interactions, which allows scientists to use them as clean probes in various experiments.

Overall, muons are vital for advancing understanding in both fundamental physics and applied sciences, owing to their unique properties and natural abundance from cosmic ray interactions.