Following my investment on the Muon system, my physics interests have turned – since 2001 – to searches for final states which involve muons. Already in 2002 (well before the start of the data taking and the Higgs discovery), I joined the ATLAS Higgs group. My studies focused on ways to fully exploit the Higgs discovery potential, namely: to improve the muon reconstruction, to study the influence of the alignment of the muon chambers on the Higgs width, to optimize the selection criteria, to create background determination tools etc. I contributed heavily to the group which first observed the Higgs→4l decays. After the Higgs discovery I have contributed to studies of the different production mechanisms and searches for additional higher mass Higgs decaying to four leptons or two leptons and two jets. I have also contributed with three students’ thesis work on the searches for high mass W/Z like bosons decaying to lepton+neutrino or two leptons.