Dalitz Decay $H\to\,f\bar{f}\gamma$ as a Background for   $H\to\gamma\,\gamma$
  The Dalitz decay $H\to\,f\bar{f}\gamma$ is calculated for very small $f\bar{f}$ invariant masses where the $f\bar{f}$ pair could be mistaken for a photon in analysis of $H\to\gamma\gamma$ decays. Using the ATLAS cuts and the full Dalitz decay amplitude, we estimate this fraction to be 7.06%. 
Duane A. Dicus and Wayne W. Repko
hep-ph