The LHCb collaboration at CERN has reported the first observation of charge-parity (CP) violation in baryon decays, marking a significant milestone in particle physics. This discovery, presented at the Rencontres de Moriond conference in March 2025, provides new insights into the fundamental differences between matter and antimatter.
CP violation refers to the phenomenon where particles and their corresponding antiparticles do not behave identically, a crucial factor in explaining why the universe is predominantly composed of matter. While CP violation has been observed in mesons—particles made up of a quark-antiquark pair—this is the first time it has been detected in baryons, which consist of three quarks and constitute the majority of visible matter in the universe.
In their study, the LHCb team analyzed data from the Large Hadron Collider, focusing on the decay of the Λ b 0 b 0 b 0
This observation opens new avenues for testing the Standard Model of particle physics and searching for physics beyond it. Understanding CP violation in baryons is essential for addressing the longstanding question of why the universe is made predominantly of matter rather than antimatter.