CMS collaboration discovers its first new particle
The excited, neutral Xi_b baryon decays in a multi-step process with long-lived particles, making it complicated for scientists to trace back to the original particle. Image: CMS collaboration
By Kathryn Grim
April 27 2012
Members of the CMS collaboration announced the experiment’s first discovery of a new particle today.
In a paper submitted to Physical Review Letters, the CMS collaboration described the first observation of an excited, neutral Xi_b baryon, a particle made up of three quarks, including one beauty quark.
The new baryon is one of many particles made up of quarks predicted by the theory of quantum chromodynamics.
“We have found a very large fraction of these particles,” said CMS physicist Vincenzo Chiochia, one of the co-leaders of the search. “But there are still very heavy ones and excited states to be discovered.”