First Observation by CMS of Higgs Production in Association with Top Quarks Published in Physical Review Letters
The first observation of the simultaneous production of a Higgs boson with a top quark-antiquark pair is being published today in the journal Physical Review Letters (PRL). This major milestone, first reported by the CMS Collaboration in early April 2018, unambiguously demonstrates the interaction of the Higgs boson and top quarks, which are the heaviest known subatomic particles. It is an important step forward in our understanding of the origin of mass. The paper features as a PRL Editors’ Suggestion and also has a Physics Viewpoint article published about it.
An event candidate for the production of a top quark and top anti-quark pair in conjunction with a Higgs Boson in the CMS detector. The Higgs decays into a tau+ lepton and a tau- lepton; the tau+ in turn decays into hadrons and the tau- decays into an electron. The decay product symbols are in blue. The top quark decays into three jets (sprays of lighter particles) whose names are given in purple. One of these is initiated by a b-quark. The top anti-quark decays into a muon and b-jet, whose names appear in red.
CMS is one of two general-purpose experiments at the LHC that have been built to search for new physics. It is designed to detect a wide range of particles and phenomena produced in the LHC's high-energy proton-proton and heavy-ion collisions and will help to answer questions such as: "What is the Universe really made of and what forces act within it?" and "What gives everything mass?" It will also measure the properties of well-known particles with unprecedented precision and be on the lookout for completely new, unpredicted phenomena. Such research not only increases our understanding of the way the Universe works, but may eventually spark new technologies that change the world in which we live as has often been true in the past.
The conceptual design of the CMS experiment dates back to 1992. The construction of the gigantic detector (15 m diameter by nearly 29 m long with a weight of 14000 tonnes) took 16 years of effort from one of the largest international scientific collaborations ever assembled: more than 4000 physicists (including 1500 students) plus 700 engineers and technicians, from around 200 institutions and research laboratories distributed in more than 40 countries all over the world.