Search for diphoton events with large missing transverse momentum in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:mn>1</mml:mn><mml:msup><mml:mrow><mml:mtext> fb</mml:mtext></mml:mrow><mml:mrow><mml:mo>−</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msup></mml:math> of 7 TeV proton–proton collision data with the ATLAS detector
Physics letters. B