Search for Supersymmetry with Gauge-Mediated Breaking in Diphoton Events with Missing Transverse Energy at CDF II

We present the results of a search for supersymmetry with gauge-mediated breaking and ˜ 𝜒 0 1 →𝛾⁢ ˜ 𝐺 in the 𝛾⁢𝛾 +missing transverse energy final state. In 2.6 ±0.2  fb−1 of 𝑝⁢ ‾‾‾ 𝑝 collisions at √𝑠 =1.96  TeV recorded by the CDF II detector we observe no candidate events, consistent with a standard model background expectation of 1.4 ±0.4 events. We set limits on the cross section at the 95% C.L. and place the world’s best limit of 149  GeV/𝑐2 on the ˜ 𝜒 0 1 mass at 𝜏 ˜ 𝜒 0 1 ≪1  ns . We also exclude regions in the ˜ 𝜒 0 1 mass-lifetime plane for 𝜏 ˜ 𝜒 0 1 ≲2  ns .