Search for the radiative penguin decays <math><msup><mi>B</mi><mn>0</mn></msup><mo>→</mo><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><mi>γ</mi></math> in the Belle experiment

We report results from the first search for the rare penguin-dominated decay mode B0→KS0KS0γ, which can result from the production of tensor mesons f(1270) and f′(1525) in association with a photon. The search uses the full data sample of 772×106 BB¯ pairs collected with the Belle detector at the KEKB asymmetric-energy e+e− collider. No statistically significant signals are observed in the KS0KS0 invariant mass range 1 GeV/c2<MKS0KS0<3 GeV/c2, and the following upper limits at the 90% confidence level are obtained: B(B0→KS0KS0γ)<5.8×10−7, B(B0→f2γ)×B(f2(1270)→KS0KS0)<3.1×10−7, and B(B0→f2′γ)×B(f2′(1525)→KS0KS0)<2.1×10−7. In addition, 90% confidence-level upper limits in the range of [0.7–2.9]×10−7 are also obtained on the B0→KS0KS0γ branching fraction in bins of MKS0KS0.