Search for massive resonances decaying into pairs of boosted bosons in semi-leptonic final states at sqrt(s) = 8 TeV

TL;DR

This paper reports a search for new heavy resonances decaying into pairs of bosons in semi-leptonic final states at 8 TeV, using jet substructure techniques to improve sensitivity and setting the most stringent limits to date on bulk graviton production.

Contribution

It introduces a novel analysis combining semi-leptonic and all-hadronic channels with jet substructure methods to enhance detection sensitivity for diboson resonances at the LHC.

Findings

Set upper limits on resonance production cross sections between 700 and 10 fb.

Achieved the most stringent limits to date on bulk graviton models in diboson final states.

Improved analysis sensitivity by combining different final state channels.

Abstract

A search for new resonances decaying to WW, ZZ, or WZ is presented. Final states are considered in which one of the vector bosons decays leptonically and the other hadronically. Results are based on data corresponding to an integrated luminosity of 19.7 inverse femtobarns recorded in proton-proton collisions at sqrt(s) = 8 TeV with the CMS detector at the CERN LHC. Techniques aiming at identifying jet substructures are used to analyze signal events in which the hadronization products from the decay of highly boosted W or Z bosons are contained within a single reconstructed jet. Upper limits on the production of generic WW, ZZ, or WZ resonances are set as a function of the resonance mass and width. We increase the sensitivity of the analysis by statistically combining the results of this search with a complementary study of the all-hadronic final state. Upper limits at 95% confidence level are set on the bulk graviton production cross section in the range from 700 to 10 femtobarns for resonance masses between 600 and 2500 GeV, respectively. These limits on the bulk graviton model are the most stringent to date in the diboson final state.