08.10.2013

DESY congratulates François Englert and Peter Higgs on Nobel Prize in Physics

The Nobel Committee today awarded the Nobel Prize in Physics to François Englert and Peter Higgs for their theory explaining the mass of elementary particles. Germany’s particle physics centre DESY congratulates the Nobel laureates on this important recognition of their work. The physics theory, which has since become known as the “Higgs mechanism”, explains the mass of elementary particles through the ubiquitous interaction with a scalar Higgs field. With the discovery of the associated Higgs particle at the LHC particle accelerator at the European particle physics laboratory CERN in July 2012, the mechanism was finally confirmed after 48 years of searching. Numerous German researchers were significantly involved in the discovery.

François Englert (left) and Peter Higgs at CERN on 4 July 2012, on the occasion of the announcement of the discovery of a Higgs boson by the ATLAS and CMS experiments. Photo: Maximilien Brice/CERN

“For me, it is a triumph of the human spirit to see the theory of how our universe works, which was postulated almost 50 years ago, experimentally confirmed today,” says DESY Director for Particle Physics, Prof. Joachim Mnich. “Generations of particle physicists have been looking for this particle, and its discovery is due not least to many young scientists who have built the LHC experiments and analysed the data with great dedication.”

The Higgs particle is a key puzzle piece of the Standard Model of particle physics, the theory that describes the interactions of the elementary particles and forces. In its first approaches, the Standard Model had a flaw: All exchange particles, which mediate the forces, had to be massless. However, experiments show clearly that this is not true for all those particles. To resolve this contradiction, in the 1960s, Peter Higgs as well as Robert Brout († 2011) and François Englert independently introduced a new field into the theory. This Higgs field permeates the entire universe and is supposed to give particles their mass. The stronger the interaction between the Higgs field and the elementary particle, that is, the more the Higgs field slows the particle down, the greater the mass of the particle. In 1964, Peter Higgs recognized that a new particle should be associated with this field – hence the particle bears his name.

In July 2012, scientists of the particle physics experiments ATLAS and CMS at the LHC announced that they had detected a particle with properties that matched those of the Higgs particle. DESY is involved in both experiments. By the end of 2012, the researchers were able to confirm their results through more accurate measurements and say with certainty that the new particle they had found was indeed a Higgs particle. The exact proof of whether it is precisely the Higgs particle predicted by the Standard Model of particle physics, or another Higgs particle with different characteristics, is still pending. “There are still many questions to clarify: Why do the particles have precisely the mass they have? Is the Higgs particle exactly the one predicted by the Standard Model, or only one out of several supersymmetric Higgs particles? The discovery of the particle was only the first step on a probably still long journey of discovery,” says Mnich.

Prize announcement: www.nobelprize.org