The Sussex ATLAS Team Celebrates Ten Years of the Higgs Boson
By: Antonella De Santo
Last updated: Thursday, 30 June 2022
On 4th July 2022, the Sussex research team working on the ATLAS experiment at CERN’s Large Hadron Collider (LHC), led by Professor Antonella De Santo, will be joining worldwide celebrations to mark the tenth anniversary of the joint announcement of the discovery of the Higgs boson by the ATLAS and CMS Collaborations.
The Higgs boson was the last building block of the Standard Model of particle physics to be discovered, nearly fifty years after its existence was first postulated. The so-called Higgs mechanism, of which the Higgs boson is a direct manifestation, explains how elementary particles can have a non-zero mass. While some of the known elementary particles are exactly massless (as it is the case for the “light particle” known as the photon), or have a very small mass (for example, the electron), other particles have much larger masses – in the case of the heaviest quark, the top quark, reaching up to nearly two-hundred times the mass of the proton. According to the theory originally postulated by Professor Higgs and, independently, Professors Brout and Englert, a Higgs field is thought to extend throughout the universe, like an invisible molasse. Elementary particles whiz through the Higgs field more or less easily according to how strongly they interact with it – the stronger the interaction with the Higgs field is, the greater the mass of the elementary particle will be. The Higgs boson itself is a wave in the Higgs field, a “ripple” that manifests itself in the form of the new particle observed at the Large Hadron Collider for the first time in 2012.
Dr Mark Sutton from the Sussex ATLAS team, who was based at CERN for the much of the “LHC Run-1” data-taking period between 2009-2012, has fond memories of the frantic time preceding the Higgs boson discovery. Dr Sutton was responsible for the development, commissioning and operations of the ATLAS Inner Detector Trigger system, which was crucial to collect the data used for the Higgs boson discovery. Much like the brain of the experiment, the ATLAS Trigger system uses real-time measurements in the detector components to take split-second decisions about which of the billions of proton-proton collisions produced in ATLAS every second may contain an interesting “event”, such as a candidate Higgs boson decay. Dr Sutton says: ``It was such an exciting time to be at CERN, particularly because, before the LHC, it was not clear at all that the Higgs boson existed and could be observed experimentally. I feel really honoured to have had this once-in-a-lifetime opportunity to be instrumental in such a historic discovery.’’
Professor De Santo, who on 4th July 2012 was in London with the other team leaders of the ATLAS and CMS contingents in the UK to follow the announcement of the discovery, remembers: ``What a day that was! I was on first train from Brighton to Victoria, and arrived just in time for a quick coffee before the lights went down and the screens lighted up. It was a most amazing feeling to know that we were part of the history of particle physics in the making.’’
Ten years on, the lasting importance of the Higgs boson discovery cannot be overstated. The study of the properties of this once-elusive particle continues unabated, yielding crucial and novel results from the largely unexplored Higgs sector of the Standard Model. Precision measurements of the Higgs boson and its properties open new windows to search for new physics phenomena and explore fundamental questions about our Universe – from why we are here to the origin of Dark Matter and beyond. The Sussex ATLAS group is excited to be playing a leading role in attempting to answer such questions.
As part of the celebrations taking place at the University of Sussex for the Higgs boson’s 10th birthday, Sussex’s own Dr Josh McFayden will give a talk on the current status and prospects of Higgs boson physics at the Large Hadron Collider. The talk will take place in hybrid mode on 6th July 2022, 6.30pm, being broadcast online from the Fulton A lecture theatre on the Sussex campus (*). To register for the event, whether you plan to attend in person or online, please follow the Eventbrite link appended below (**).
(*) Fulton A, University of Sussex, Falmer, BN1 9RH