2 experiments defy physics rule book Tiny particles called muons not acting as scientists expected By SETH BORENSTEIN, Associated Press Published: April 13, 2021, 6:05am Share: 3 Photos Nikolai Bondar works on the LHCb Muon system at the European Organization for Nuclear Research Large Hadron Collider facility outside of Geneva in 2018. (Maximilien Brice, Julien Marius Ordan/CERN) Photo Gallery Preliminary results from two experiments suggest something could be wrong with the basic way physicists think the universe works, a prospect that has the field of particle physics both baffled and thrilled. Tiny particles called muons aren’t quite doing what is expected of them in two different long-running experiments in the United States and Europe. The confounding results – if proven right – reveal major problems with the rule book physicists use to describe and understand how the universe works at the subatomic level.