New kind of Higgs boson events detected at the Large Hadron Collider

Refining the search for new physics.

Scientists working on the CMS and ATLAS detectors at the Large Hadron Collider, including a large group from Imperial College London, have announced the latest findings on the Higgs boson’s properties.

For the first time, they reported the Higgs boson decaying into two muons. This rare phenomenon has been difficult to detect as muons are relatively light, meaning they interact weakly with Higgs bosons.

Higgs bosons are made when two protons smash together at nearly the speed of light in the Large Hardon Collider, however, they are unstable ‘rotting’ into other particles they have cooperated with. The decay into a couple of muons happens for one in each 5,000 Higgs bosons produced.

Scientists are going through two ways to explore the properties of the Higgs boson for deviations from the Standard Model of particle physics. One is to search for extremely rare processes – decays that are sensitive to interactions of the Higgs boson with new particles. The further muon pair decay is one such process. The other way is to get ever-more precise measurements of known couplings. 

Detection of a Higgs boson decaying into two photons
Detection of a Higgs boson decaying into two photons (green rectangles). Credit: CERN

Scientists have been leading this for another Higgs boson decay that results in two photons – particles of light. They recently looked at all the data gathered from the CMS detector from 2016 to 2018 to get the most precise measurements of Higgs boson two-photon decay to date.

Imperial physicists were critical to the overall design, construction, and operation of the CMS detector and continue to play the main job in boosting its capacities to detect and sort data through hardware and software upgrades, just as on the investigation of the outcomes.

Leader of the Higgs CMS group Dr. Nicholas Wardle, from the Department of Physics at Imperial, said: “Neither of these results would have been possible without the excellent calorimetry, trigger or tracking sub-systems at CMS. The UK, in particular Imperial’s high-energy physics group, plays a huge role in the design and construction of these systems.”

See stories of the future in your inbox every morning.