2019 High Energy and Particle Physics Prize of the European Physical Society

The European Physical Society has awarded its 2019 High Energy and Particle Physics Prize to the scientists involved in the discovery of the top quark, and the initial measurements of its properties.  This work was carried out at the Tevatron proton/anti-proton collider at Fermilab, near Chicago, between 1992 and 2011.  Before the Large Hadron Collider at CERN was completed, the Tevatron was the world’s highest-energy particle accelerator.

Data from the Tevatron was recorded by two large experiments, called D0 and CDF.  UA physics faculty members Elliott Cheu, Ken Johns, John Rutherfoord, and Erich Varnes, as well as emeritus faculty member Michael Shupe, were part of the D0 collaboration (which, at its peak, included over 600 physicists from 80 institutions) and played key roles in this work, including Johns’ leadership of a large project to improve D0’s ability to detect muons, and Varnes’ development of a new method for measuring the mass of the top quark.

The top quark is the heaviest elementary particle known, with a mass about 175 times that of a proton.  This large mass gives the top quark a special connection to the Higgs boson, which was discovered at the LHC in 2012, and detailed measurements of the top quark, the Higgs boson, and the interactions between them are ongoing to determine if everything is behaving as our current theory would predict.