A search for invisible decays of the Λ baryon is carried out in the process J/ψ→ΛΛ¯ based on (1.0087±0.0044)×1010 J/ψ events collected with the BESIII detector located at the BEPCII storage ring. No signals are found for the invisible decays of Λ baryon, and the upper limit of the branching fraction is determined to be 7.4×10-5 at the 90% confidence level. This is the first search for invisible decays of baryons; such searches will play an important role in constraining dark sector models related to the baryon asymmetry.
Предметные области OECD FOS+WOS
- 1.03 ФИЗИЧЕСКИЕ НАУКИ И АСТРОНОМИЯ