Doubly Strange Nucleus Observed Physics 14, s15 Particle physicists have detected a short-lived nucleus containing two strange quarks, whose properties could provide new insights into the behavior of other nuclear particles. S. Hayakawa/Japan Atomic Energy Agency S. Hayakawa/Japan Atomic Energy Agency × Baryons are three-quark particles, such as protons, neutrons, and the lesser-known hyperons. The latter’s claim to fame is that they contain at least one strange quark. Researchers study hyperons to understand how baryons interact. One experiment, known as the J-PARC E07 experiment, has now uncovered a very rare interaction in which a hyperon with two strange quarks binds to a normal nucleus [1]. By measuring precisely how this “hypernucleus” decayed, the team behind the experiment was able to determine the particles’ binding energy.