Higgs look-alikes at the LHC

The discovery of a Higgs particle is possible in a variety of search channels at the LHC. However , the true identity of any putative Higgs boson will, at first, remain ambiguous until one has experimentally excluded other possible assignments of quantum numbers and couplings. We quantify the degree to which one can discriminate a Standard Model Higgs boson from " look-alikes " at, or close to, the moment of discovery at the LHC, focusing on the fully- reconstructable " golden " decay mode to a pair of Z bosons and a four-lepton final state.