Higher-order QCD effects in the Higgs to ZZ search channel at the LHC

We present a consistent analysis of the signal as well as the irreducible background for the search of the SM Higgs boson in the ZZ decay channel at the LHC. Soft-gluons effects are resummed up to next-to-leading logarithmic accuracy, and the results are compared to those obtained with fixed order calculations and the MC@NLO event generator. The soft-gluon effects are typically modest but should be taken into account when precise predictions are demanded. Our results show that the signal over background ratio can be significantly enhanced with a cut on the transverse momentum p(T)(ZZ) of the ZZ pair. We also introduce a fully transverse angular variable that could give information about the CP nature of the Higgs boson. (C) 2008 Elsevier B.V. All rights reserved.