Seeking answers to questions about the universe
Curiosity is as old as humankind, and it is CERN’s raison d’être. When the Laboratory was founded, the structure of matter was a mystery. Today, we know that all visible matter in the Universe is composed of a remarkably small number of particles, whose behaviour is governed by four distinct forces. CERN has played a vital role in reaching this understanding.
Throughout the 1960s, theories were advanced to explain two forces – the weak force and the electromagnetic force – in the same framework. In the 1970s, a CERN experiment brought the first experimental evidence for these ideas, and in the 1980s the discovery of the W and Z particles – carriers of the weak force – brought confirmation of the theory. CERN researchers Simon van der Meer and Carlo Rubbia shared the 1984 Nobel Prize in physics for this discovery.
During the 1990s, CERN experiments designed in light of this discovery tested the so-called electroweak theory with extreme precision, putting it on solid experimental ground. In 2010, the LHC started to provide particle collisions in a new high-energy domain, reproducing the conditions a fraction of a second after the Big Bang. This led to the discovery at CERN of a Higgs boson – long sought as the particle linked to the mechanism that gives mass to elementary particles.
Beyond CERN's flagship accelerator, the LHC, the Laboratory has a rich and diverse scientific programme. From the study of antimatter at the antiproton decelerator, to nuclear physics at CERN's longest-running experimental facility, ISOLDE. Experiments at other accelerators and facilities both on-site and off are an equally important part of the Laboratory’s activities. Supporting all the experiments is a very strong theory programme, which carries out cutting-edge research in theoretical particle physics.
Exploring the unanswered questions
CERN’s world-class research has transformed our understanding of the universe, yet many fundamental mysteries remain:
Why is the universe made only of matter, with hardly any antimatter?
Why is gravity so weak compared to other forces?
Is there only one Higgs boson, and does it behave exactly as expected?
With 95% of the mass and energy of the universe still unknown, there is still much to learn about how and why matter in the universe is the way it is.
To continue in our understanding, an upgrade to the High-Luminosity LHC is under way. In addition, a feasibility study is progressing for a post-LHC collider at CERN – a unique tool to study the universe in laboratory conditions and to push energy and intensity frontiers in the search for new physics.