Signal "spot'' and mass window cut for the low mass SM Higgs

An attempt to improve signal significance for the Standard Model low mass Higgs boson produced in $WH (H\to\bbbar)$ channel in ATLAS experiment is described in the Note. The most significant background processes, WZ, W+jets and $\ttbar$, are considered. The approach exploits the condition for the minimal angular separation in two-particle decays. The analysis was not aimed to get the final number of the Higgs over the background, but to examine some new kinematical cuts and check the potential improvements.