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

TL;DR

This study searches for baryon number violation through $\Lambda-ar{\Lambda}$ oscillation in $J/\psi$ decays using a large dataset, setting new upper limits on the oscillation probability and parameter.

Contribution

First search for $\Lambda-ar{\Lambda}$ oscillation in $J/\psi$ decays with a large dataset, establishing the most stringent upper limits to date.

Findings

No evidence of $\Lambda-ar{\Lambda}$ oscillation was observed.

Upper limit on oscillation probability is $1.4 imes 10^{-6}$.

Oscillation parameter is constrained to be less than $2.1 imes 10^{-18}$ GeV.

Abstract

Using $(10087\pm44)\times 10^{6}$ $J/\psi$ 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.