Measurement of the Λ electric dipole moment with an entangled baryon-antibaryon system.
The dominance of matter over antimatter in the Universe has consistently driven the pursuit of new physics beyond the Standard Model that violates charge-parity symmetry. Strange baryons (hyperons) remain a largely unexplored territory in which interactions between hyperons and particles from new physics could induce a nontrivial electric dipole moment (EDM). However, direct measurements of hyperon EDMs through spin precession are highly challenging owing to their short lifetimes. In this work,
The dominance of matter over antimatter in the Universe has consistently driven the pursuit of new physics beyond the Standard Model that violates charge-parity symmetry. Strange baryons (hyperons) remain a largely unexplored territory in which interactions between hyperons and particles from new physics could induce a nontrivial electric dipole moment (EDM). However, direct measurements of hyperon EDMs through spin precession are highly challenging owing to their short lifetimes. In this work, we introduce a method to extract the EDM of the lightest hyperon, Λ, using the entangled [Formula: see text] system. Our result is consistent with zero, achieving a three-orders-of-magnitude improvement over the previous upper limit established in the 1980s with comparable statistics, providing stringent constraints on potential new physics.
