Search for a Higgs boson in the decay channel H to ZZ(*) to q qbar l-l+ in pp collisions at sqrt(s) = 7 TeV

TL;DR

This paper reports a search for the Higgs boson decaying into two Z bosons with a final state of two quark jets and two leptons, using 7 TeV proton-proton collision data from the CMS detector, setting upper limits on its production.

Contribution

It introduces a novel analysis method employing kinematic, topological, and jet flavor classification to search for the Higgs in the q q-bar l-l+ decay channel at the LHC.

Findings

No evidence for the Higgs boson was observed.

Upper limits on Higgs production cross section were established.

Analysis techniques improved background discrimination.

Abstract

A search for the standard model Higgs boson decaying into two Z bosons with subsequent decay into a final state containing two quark jets and two leptons, H to ZZ(*) to q q-bar l-l+ is presented. Results are based on data corresponding to an integrated luminosity of 4.6 inverse femtobarns of proton-proton collisions at sqrt(s)=7 TeV, collected with the CMS detector at the LHC. In order to discriminate between signal and background events, kinematic and topological quantities, including the angular spin correlations of the decay products, are employed. Events are further classified according to the probability of the jets to originate from quarks of light or heavy flavor or from gluons. No evidence for the Higgs boson is found, and upper limits on its production cross section are determined for a Higgs boson of mass between 130 and 600 GeV.