Fig. 4: The process of Figure 3, as observed by an LHC detector (ATLAS or CMS). These sketches show two possibilities: one (above) where the S particles have short lifetimes and decay after traveling a microscopic distance, and one (below) where the S particles have long lifetimes and travel a meter or so before decaying. (To guide the eye, dashed lines show their paths, but note they leave no trace in the detector). The muon and anti-muon are detected as localized electronic signals (black dots) as they pass through the tracker (pink) and muon system (green); the bottom quark and anti-quark generate sprays of hadrons (“jets”) which are detected as they travel through the tracker and stop in the energy detector (“calorimeter”, blue). Neither case is easy to identify as coming from a Higgs decay; the second case is much more challenging for the detector software to interpret correctly.
Left: The north rose window of Notre-Dame cathedral in Paris (Photo: Julie Anne Workman, via Wikipedia). Right: The inner tracker of the CMS Experiment at the LHC in Geneva (Photo: 2008 CERN). After an image composed by Daniel Denegri, for his presentation at the Orsay Higgs Hunting 2012 conference.