Large Hadron Collider prepares to probe more mysteries of the universe

25 Mar 2015

The Large Hadron Collider (LHC), site of the famous 2012 discovery of the elusive Higgs boson, (See: CERN researchers say new particle discovered is Higgs boson) is due to switch back on next week.

 
STFC/Imperial College London  
During the past two years of down-time, the LHC has been upgraded and it will now be able to smash particles together at higher energies than its previous run. The LHC will run at twice the energy of the experiments that discovered the Higgs boson, the long-hypothesised particle that gives all others mass.

The higher the energy of collision, the closer physicists can get to the conditions of the Big Bang, and they hope this will allow them to gain more insights into the workings of the universe.

Many Imperial College London researchers are involved in the work of the LHC. They were amongst those who designed, engineered and built the CMS detector - one of the LHC's two main experiments - and analysed its results.

Professor Jerome Gauntlett, head of the theoretical physics group at Imperial, says, ''The stakes are high, and physicists are tremendously excited about what it will reveal. We will certainly learn more about the properties of the Higgs boson, but we may also discover new elementary particles, including particles that could comprise the mysterious dark matter that pervades the universe.''

Astronomical observations point to an unseen source of gravitational force in the universe, and it's this missing component that physicists call 'dark matter'. It is thought to make up most of the matter in the universe, but has so far been impossible to detect. However, it must have been produced at the beginning of the universe, so creating conditions similar to the Big Bang might just create dark matter too.

Several scientists at Imperial are involved in experiments at the LHC. While the Higgs boson was a large piece in the puzzle of the so-called standard model of physics, there are still many questions to be explored.

Theoretical physicist Professor Arttu Rajantie of the department of physics at Imperial says, ''The re-start of the Large Hadron Collider takes us to exciting new territory. With the upgraded LHC, we can reach significantly higher energies, with the prospect of unexpected new discoveries. For example, the new MoEDAL experiment will be searching for magnetic monopoles, particles carrying a single magnetic pole, whose existence would shed new light on electromagnetism and the unification of forces.

''More precise measurements of the properties of the Higgs boson will also be very interesting, and may provide answers to some deep questions about the beginning and the ultimate fate of the Universe.''

While the machine's beams should be up and running full circle in the next week, collision experiments likely won't begin for another couple of months.

High energy physicist Dr David Colling from the department of physics at Imperial says, "The increase in the machine energy during this second running period gives great scope for discovering physics beyond the standard model.

"Some discoveries could come very quickly, within weeks after start up, while others would require the collection of large amounts of data over several years. Which, if either, of these we will find depends on physics that we don't yet understand."