Higgs Physics

The Liverpool ATLAS group has had a long interest in Higgs physics including in the discovery of the Higgs boson in 2012. This discovery led to the award of the Nobel Prize for Physics to Francois Englert and Peter Higgs, who predicted the existence of the particle some 50 years before! Since the discovery of the Higgs boson we, here at Liverpool, have played a major role in understanding the properties and searching for its rarer decays.

One of our main focuses was to establish and measure the rate decay of the Higgs to b-quarks, which although it’s the most abundant decay, is tricky because it looks like a lot of the events produced in ATLAS. We observed this decay in 2018 and have continued to make more precise measurements since. We are also looking for the rarer decays of the Higgs boson to muons and to charm quarks. A summary of the measurements can be found here where the measured coupling is plotted against the particle mass.   We are also searching for non-standard decays of the Higgs boson to a pair of different leptons, to invisible particles such as dark matter and for extra Higgs bosons that may appear at larger masses.  

The Higgs boson is one of the few particles that is thought to be able to interact with itself. Measurement of the Higgs self-interaction enable us to measure the Higgs potential, which governs how the universe formed and its eventual fate.  In ATLAS this can be measured by searching for extremely rare events where two Higgs bosons occur simultaneously.  At Liverpool we focus on those events where one Higgs boson decays to tau leptons and the other to b-quarks. As yet no concrete evidence has been found, but the searches allow us to put strong limits on the Higgs self-interaction strength. 

Academic and Research Staff 

  • Dr Jordy Degens 
  • Prof Monica D’Onofrio
  • Prof Carl Gwilliam 
  • Dr Jan Kretzschmar 
  • Prof Andrew Mehta 
  • Dr Nikos Rompotis

PhD Students 

  • Mr Bhupesh Dixit 

Back to: Department of Physics