The Lambda 0 Baryon

<p><strong>The Field Guide to Particle Physics : Season 2<br></strong><a href="https://pasayten.org/the-field-guide-to-particle-physics">https://pasayten.org/the-field-guide-to-particle-physics</a><br>©2022 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 Lambda 0 Baryon</strong></p><p>With a mass of well over 1115 mega electron volts, about 20 percent more than the proton, the Lambda 0 is a rare, but historic particle to find.</p><p>Inside the Lambda Baryons you’ll find an <a href="https://pasayten.org/the-field-guide-to-particle-physics/up-and-down-quarks">up quark, a down quark</a> and… something else. </p><p>The first Lambda Baryon was <a href="https://journals.aps.org/pr/abstract/10.1103/PhysRev.80.1099">first observed</a> in 1950. In what amounts to a weather ballon. Way up high in the atmosphere. On a photographic emulsion plate. Particle physics was a different game back then!</p><p>Physicists KNEW it was a baryon because it decayed into a <a href="https://pasayten.org/the-field-guide-to-particle-physics/proton">proton</a>. And it was heavy.</p><p>Heavy particles decay quickly, and the Lambda was heavy. But it did not decay quickly enough. It stayed around for quite a while, a bit less than a nanosecond, which is rather long by particle physics standards. Especially for a baryon.</p><p>Very strange. </p><p>The long lifetime of the Lambda 0 was so strange that physicists knew there was something special about that particle. It had a special property. And in the 50’s this new property of particles was showing up in more and more experiments. Because they had no idea what it could be, that called this property strangeness. For better or f