Shining a light on the dark sector
In the middle of June, researchers from all over the world will gather in Lund to discuss the latest news on the unknown sides of the universe and the Higgs boson.
Four years ago, researchers at CERN proved the existence of the Higgs boson. The discovery explains why all particles down to the smallest level must have mass. It also explains why different laws within physics give rise to very different reactions, which in turn give us the complex world we live in.
In this way, the Higgs boson complements particle physics’ explanatory model of the world, known as the Standard Model.
“To begin with, the Standard Model did not allow for particles to have a mass. This problem was solved in the 60s by the introduction of the Higgs field and the Higgs particle, which interacts with other particles, giving them mass. It took more than 40 years, however, before we finally found the Higgs boson”, says Leif Lönnblad, professor of Particle Physics in Lund.
He and his colleague Professor Torsten Åkesson, together with other colleagues at the divisions for experimental and theoretical particle physics, have prepared this year’s LHC conference. They themselves are deeply involved in the research and experiments underway at CERN. The hope is that some of the many questions raised by LHC will find answers over the six days in which global expertise will be gathered in Lund.
The hottest topic right now is to find deviations from the Standard Model, that which lies beyond the physicists’ explanation and knowledge of the world and the universe.
“For example, the Standard Model cannot explain the dark sector, i.e. what dark matter consists of or what dark energy is”, says Torsten Åkesson.
That such a thing as dark matter exists has been established. One proof is the way in which stars and galaxies move and rotate. Researchers have calculated that it takes five times more mass than that generated by gas, dust, stars and planets for the stars and their planetary systems to move as they do.
The only reasonable explanation in terms of physics is that there is more mass in the universe, a great deal more than what has been discovered so far. The undiscovered mass consists of particles which the researchers are frenetically searching for.
“The collective name is dark matter, as the particles we are looking for neither absorb nor emit light”, says Leif Lönnblad.
“Dark energy is something else. We know that it exists insofar as the universe is expanding and that this expansion is accelerating instead of slowing down. Some form of energy is driving this acceleration, but we don’t know what it is or what causes it”, says Torsten Åkesson.
The majority of all mass is thus of a completely different nature to the particles which make up humans, animals, planets and stars. As the answers to the questions on dark matter and dark energy are revealed, they will probably change the way in which we see the world.
“It is pure speculation, but we may get a completely new Physics, just as we have the Standard Model for our known matter”, says Torsten Åkesson.
“I think it will change how people think. Just as people changed when we realised the Earth is not unique and not even the centre of the universe. More knowledge about the dark sector could make people realise that everything we have known up to now as matter in the universe is merely a small part of it, a minority phenomenon”, says Leif Lönnblad.
Text: Jan Olsson
Facts on the conference
The Large Hadron Collider Physics Conference (LHCP2016) is completely dedicated to research and findings from the particle accelerator at the CERN laboratory. The conference is the largest of its kind in the world. This year’s conference is the fourth edition and will be held in Lund 13–18 June. Around 360 researchers from all over the world will take part.
The six-day conference will include a special event for the general public on Thursday 16 June. The event moderator, Lisa Kirsebom, will address questions to Ulf Danielsson, professor of Theoretical Physics in Uppsala. Among other subjects, they will discuss dark matter and dark energy and what new knowledge will come to mean for people’s concept of the world. The general public will have the opportunity to ask questions and meet local researchers. Place: Academic Society’s Large Hall. Time: 20:00–21:30.
More information can be found on the website: lhcp2016.hep.lu.se