Search for K s 0 → 2γ decay

A search for the K s 0 → 2γ decay was carried out using the 180 litre xenon bubble chamber exposed to a separated K+ beam with momentum 0.85 GeV/c at the ITEP proton accelerator. The branching ratio Γ(K s 0 →-> 2γ)/Γ(K s 0 → all) was found to be compatible with zero with a 90% c.l. upper limit 1.33 · 10−4.