What are backgrounds

Figure 1

Two diagrams showing a top quark and antitop quark being produced where one decays through a leptonic process and the other decays through a hadronic process. The first image shows the hadronic decay in a non-boosted state and the second image shows the hadronic jets overlapping because of the boosted nature of the decay.
Representation of the resolved (left) and boosted (right) regimes of a top-quark pair decay. From the thesis of M. Missiroli “Searches for top-antitop quark resonances in semileptonic final states with the CMS detector”

Figure 2

Plot of 4-lepton final state from CMS showing Higgs peak
Plot of the invariant mass of 4-lepton final states from CMS showing the Higgs peak and other contributing processes.

Figure 3

Plot of 4-lepton final state from CMS showing Higgs peak with some text describing what goes into this plot.
There’s a lot that goes into this plot!

Data-driven background estimation

Figure 1

A plot of the invariant mass of muon pairs from CMS open data showing the $J\psi$ peak on a falling background.
A plot of the invariant mass of muon pairs from CMS open data showing the \(J\psi\) peak on a falling background.

Simulation-based background estimation

Figure 1

A plot of the ttbar invariant mass from our analysis with simulation and collision data labeled.
A plot of the ttbar invariant mass from our analysis with simulation and collision data labeled.