Search for heavy resonances in the W/Z-tagged dijet mass spectrum in pp collisions at 7 TeV

TL;DR

This paper reports a search for heavy resonances decaying into vector bosons or quark-vector boson pairs in proton-proton collisions at 7 TeV, using jet substructure techniques to identify hadronic decays and setting mass limits.

Contribution

It introduces advanced jet substructure methods to improve the identification of hadronic vector boson decays in resonance searches at the LHC.

Findings

Excluded excited quark resonances below 2.38 TeV for qW decays.

Set upper limits on cross sections for various resonance decay channels.

Demonstrated effectiveness of jet substructure techniques in high-energy resonance searches.

Abstract

A search has been made for massive resonances decaying into a quark and a vector boson, qW or qZ, or a pair of vector bosons, WW, WZ, or ZZ, where each vector boson decays to hadronic final states. This search is based on a data sample corresponding to an integrated luminosity of 5.0 inverse femtobarns of proton-proton collisions collected in the CMS experiment at the LHC in 2011 at a center-of-mass energy of 7 TeV. For sufficiently heavy resonances the decay products of each vector boson are merged into a single jet, and the event effectively has a dijet topology. The background from QCD dijet events is reduced using recently developed techniques that resolve jet substructure. A 95% CL lower limit is set on the mass of excited quark resonances decaying into qW (qZ) at 2.38 TeV (2.15 TeV) and upper limits on the cross section for resonances decaying to qW, qZ, WW, WZ, or ZZ final states.