image: Figure: The research team discovered that the decay could produce CP violation effects one order of magnitude larger than previously predicted, as illustrated by the two quark diagrams on the left.
Credit: ©Science China Press
For a long time, the scientific community has been puzzled by the dominance of matter over antimatter in the universe. CP violation is considered a crucial element in unraveling this cosmic mystery. As Nobel laureate Tsung-Dao Lee remarked, "Symmetry reveals the beauty of the universe, while asymmetry generates its substance."
Previous research has identified unexpectedly large CP violation effects in charmed meson decays, but studies in charmed baryon decays had not reached clear conclusions. To explore this phenomenon systematically, Professor Xiao-Gang He and Dr. Chia-Wei Liu of the Tsung-Dao Lee Institute (TDLI) at Shanghai Jiao Tong University employed SU(3) flavor symmetry theory combined with the framework of final-state re-scattering. Their analysis predicts significantly larger CP violation effects in charmed baryon decays than previously anticipated.
The study highlights that final-state re-scattering plays a crucial role in CP violation phenomena. This mechanism facilitates effective secondary interactions among particles, generating the strong phases necessary for CP violation. The predicted matter-antimatter asymmetry in charmed baryon decays could reach a level of one-thousandth, far exceeding prior theoretical estimates.
Established in Shanghai in 2017, TDLI dedicates itself to unraveling the mysteries of nature. Professor Xiao-Gang He, head of the Particle and Nuclear Physics division, stated, "The research on charm CP violation opens new pathways for experimental exploration and provides deeper insights into the fundamental mechanisms underlying the universe’s matter-antimatter asymmetry. It offers important opportunities for further tests of the Standard Model and potential discoveries of new physics."
The research findings hold promising prospects for experimental verification. Currently, experiments such as BESIII, LHCb, and Belle II already have certain detection capabilities. China's upcoming Super Tau-Charm Facility (STCF) is expected to significantly enhance sensitivity, offering sustained support for frontier exploration by the physics community.
Journal
Science Bulletin