Search for the Higgs boson in the ZZ() decay channel with the CMS experiment

A study of the sensitivity for the inclusive production of Standard Model Higgs bosons H decaying in ZZ(∗) pairs is presented with the CMS experiment at the CERN LHC pp collider at 14 TeV centre of mass energy, for the integrated luminosity of 1 fb−1 . The analysis is performed for the leptonic decay channels H → ZZ(∗) → 4` with ` = e, µ and for a mass mH in the range from 120 to 250 GeV/c 2 . Signal and background datasets obtained with a detailed Monte Carlo simulation of the detector response, including the limited inter-calibration and alignment precision expected at startup luminosities, are treated using a complete reconstruction chain. A simple mH independent sequence of cuts is established which provides a clean sample of 4` events while preserving the highest signal detection efficiency. A signal with a significance above 2 standard deviations is found unlikely for a Higgs boson with a mass mH lying anywhere in the mass range considered. In absence of significant deviations from background expectations, upper limits on the production cross-section of a Standard Model-like Higgs boson can be established. The limits extend beyond existing constraints.