Search for $\Lambda$-$\bar{\Lambda }$ oscillation in $J/\psi \to \Lambda \bar{\Lambda }$ decay

Abstract

Using $(10087\pm 44)\times 10^6$ $J/\psi$ decays collected by the BESIII detector at the BEPCII collider, we search for baryon number violation via $\Lambda -\bar{\Lambda }$ oscillation in the decay $J/\psi \to \Lambda \bar{\Lambda }$. No evidence for $\Lambda -\bar{\Lambda }$ oscillation is observed. The upper limit on the time-integrated probability of $\Lambda -\bar{\Lambda }$ oscillation is estimated to be $1.4\times 10^{-6}$, corresponding to an oscillation parameter less than $2.1\times 10^{-18}\mathrm{GeV}$ at $90\%$ confidence level.

8 pages, 2 figures