A massive 50% difference between how matter and antimatter behave could finally explain why the universe exists.
April 23, 2026
Original Paper
Large CP violation in $\Lambda_b\rightarrow \Lambda D$ decays and extraction of the Cabibbo-Kobayashi-Maskawa angle $\gamma$
arXiv · 2604.17877
The Takeaway
The Big Bang should have created equal amounts of matter and antimatter, which would have annihilated each other and left behind an empty universe. Physicists are searching for CP violation, which is a slight preference for matter over antimatter. This study predicts that certain baryon decays will show a massive asymmetry of up to 50%. Most known asymmetries are tiny fractions of a percent, making this a huge potential breakthrough. If confirmed, this would be a major clue in solving the mystery of why there is any stuff in the universe at all. It points to a deep imbalance in the fundamental laws of physics.
From the abstract
Motivated by the first observation of CP violation in $b$-baryon decays, the search for baryonic decays exhibiting large CP violation will be a primary focus in the coming years. We propose that significant CP-violating effects exist in the decay $\Lambda_b \to \Lambda D$, where $D$ denotes a CP eigenstate of the $D^0 - \bar{D}^0$ system. The predicted CP asymmetries for both the CP-even and CP-odd modes can reach magnitudes as large as $50\%$, making these decays promising targets for measureme