ggH rejection for double Higgs search at LHC

Higgs potential can be written as V(h)=1/2m2HH2+λvH3+λH4 where second and third components represent Higgs boson self interaction, v is Higgs field vacuum expectation value (vev). This interaction is proportional to λ, which is called Higgs self-coupling constant. In the Standard Model, there is a direct relation between the self-coupling constant,and the Higgs boson mass: mH=√2λv. mH and v is known with good precision, so if the SM potential is right, one can predict λ value with a very hight precision. Otherwise, this relation will be modified. The only way to check it is direct measurement of λ through the Higgs self-coupling. The main background channels are ttH, VH and ggH. Single Higgs background presents the biggest problem as it is situated under the Mγγ peak. The algorithm for ttH rejection was already made, so the most interesting channel if ggH, as it is not so well known. In this work we propose a tool for the rejection of one of the secondary backgrounds to the HH→ 2b2γ search, i.e., gg→H+bb.