Studying doubly charged Higgs pair production at the LHC

The little Higgs models predict a rich phenomenology for the future collider experiments. Our attention is focused on the littlest Higgs model. We carry out a Monte Carlo study of the doubly charged Higgs pair production (pp → Φ++Φ−−) in a typical LHC experiment. The branching ratios are fixed using an assumption that, in addition, the observed masses of the neutrinos are generated by triplet Higgs: BR(Φ±± → μ±μ±) = BR(Φ±± → μ±τ±) = BR(Φ±± → τ±τ±) = 1/3. We study the invariant mass distribution of same-charged muon pairs (Φ±± → 2μ±±) together with the background processes from the standard model: bb̄, tt̄, and ZZ production. To suppress the background, we propose a new type of selection rule, suitable in the case of production of the pairs of equal mass particles (Φ±±). This selection rule ensures high significance of the signal over the background of the standard model and implies very small cut of the signal under study. At the Monte Carlo level the doubly charged Higgs can be visible at the LHC in the mass range up to approximate 1 TeV.