The Muon

<p><strong>The Field Guide to Particle Physics <br></strong><a href="https://pasayten.org/the-field-guide-to-particle-physics">https://pasayten.org/the-field-guide-to-particle-physics</a><br>©2021 The Pasayten Institute <a href="https://creativecommons.org/licenses/by-sa/4.0/">cc by-sa-4.0</a><br>The definitive resource for all data in particle physics is the Particle Data Group: <a href="https://pdg.lbl.gov/">https://pdg.lbl.gov</a>.</p><p>The Pasayten Institute is on a mission to build and share physics knowledge, without barriers! <a href="http://pasayten.org/heysean">Get in touch</a>.</p><p><strong>The Muon<br></strong><br>Muons are a lesser known species of elementary particles that are extremely common, at least on Earth. They’re falling all around us, all the time. Muons are created by the collision of particles from outer space smashing into the molecules of the upper atmosphere.</p><p><br>Like all elementary particles, muons have no known size. But they do have a known mass. At 105.7 MeV, its a moderately sized mass. Its about two hundred times the mass of the <a href="https://pasayten.org/the-field-guide-to-particle-physics/electron">electron</a>. The muon’s electric charge is identical with that of the electron. Indeed, the muon and the electron share many of the same properties.</p><p>Like the electron, the muon interacts via the <a href="https://pasayten.org/the-field-guide-to-particle-physics/photon">electromagnetic</a>, weak and gravitational forces.</p><p><br>Unlike the electron, muons are not stable particles. Heavy particles seldom are. They’re heavy, and because they otherwise act like electrons, they decay to electrons. That’s a pattern we will see in particle physics, over and over again.</p><p>Muons also have antiparticle partners. Like the positron they’re also positively charged. Since muons and antimuons decay, we don’t usually worry too much about who’s who, unless we’re counting charges.</p><p><br>Muons decay courtesy of the weak nuclear force, which of course, is a very weak f