Abstract
Abstract A search for new exotic particles decaying to the VZ final state is performed, where V is either a W or a Z boson decaying into two overlapping jets and the Z decays into a pair of electrons, muons or neutrinos. The analysis uses a data sample of pp collisions corresponding to an integrated luminosity of 5 fb−1 collected by the CMS experiment at the LHC at $ \sqrt{s}=7 $ TeV in 2011. No significant excess is observed in the mass distribution of the VZ candidates compared with the background expectation from standard model processes. Model-dependent upper limits at the 95% confidence level are set on the product of the cross section times the branching fraction of hypothetical particles decaying to the VZ final state as a function of mass. Sequential standard model W′ bosons with masses between 700 and 940 GeV are excluded. In the Randall-Sundrum model for graviton resonances with a coupling parameter of 0.05, masses between 750 and 880 GeV are also excluded.
Highlights
Background estimationWe are discussing the background estimation separately for the dilepton and ETmiss channels.5.1 Dilepton channelsThe analysis of the simulated data shows that the dominant (∼90%) background after all selection requirements is the inclusive Z production (“Z+jets”), with additional contributions from tt+jets and the continuum SM diboson production (WZ and ZZ)
Model-dependent upper limits at the 95% confidence level are set on the product of the cross section times the branching fraction of hypothetical particles decaying to the VZ final state as a function of mass
A search for new exotic particles decaying to the VZ final state was performed, where V is either a W or a Z decaying to hadrons, and the Z decays to electrons, muons, or a neutrino pair
Summary
The pileup and jet energy scale (JES) systematics can potentially affect the background determination through the α(MVZ) ratio and are considered separately. The former is found to have a negligible effect. The yield differences, in each mass window, between the expected background with the positive (N+Bgd) and negative (N−Bgd) jet energy scale variation with respect to the nominal selection and fit are taken as the ±1 σ estimates for the JES systematic uncertainty. We consider several variations in the fitting procedure (fitting range, functional form, and sideband definition) These variations are compared to the difference in the number of expected background events in the mass window as estimated from data and with MC simulation. The largest of the two is used as the systematic uncertainty in the background determination
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
