4th July 2012 was a big day for the global physics community as CERN released data which showed the presence of a Higgs-like particle. The discovery was confirmed in March 2013, a great result for the theories developed in the 1960’s by Professor Peter Higgs and others.
So one year on from the greatest particle physics discovery of recent history, what else have scientists at CERN and the Large Hadron Collider (LHC) been up to?
After a three year running cycle culminating in the discovery of the long sought-after Higgs Boson the LHC was turned off this February until 2015. This long shutdown period allows for essential maintenance and upgrades but also allows scientists to analyse the unprecedented amount of data gathered. It is scheduled to resume at a much higher collision energy of 14 TeV. (What does 7 TeV mean?)
In the weeks before the LHC shutdown, the data stored in the CERN computing system surpassed 100 petabytes (a million gigabytes) – equivalent to 700 years of HD movies! The UK makes a significant contribution to the handling of this data as part of the worldwide LHC Computing Grid (wLCG), including the Tier 1 computing facility at STFC’s Rutherford Appleton Laboratory.
The main aim of the long shutdown is for major consolidation and maintenance work to be carried out across the whole of CERN’s accelerator chain with the LHC readied for higher energy running. This work should double the energy of what's already the most powerful particle accelerator in the world. Scientists believe the upgrade will enable them to discover new particles which will lead to a more complete theory of how the Universe works. The upgrade will enable the UK to continue to be at the forefront of the research being undertaken on the ATLAS and CMS detectors and maintain its leadership in this area.
By observing subtle differences between matter and antimatter, physicists at the LHCb experiment are working to understand why our Universe is made solely out of matter and what happened to all the antimatter. The first matter-antimatter asymmetry was observed at the LHCb in late April 2013 through the decays of a subatomic particle known as the B0s, only the fourth such particle known to exhibit such behaviour. The researchers hope that further experiments into other differences will eventually shed light on the dominance of matter over antimatter.
Not all research at CERN is done using the LHC. Other experiments, such as ISOLDE answer questions in nuclear physics. Most nuclei have a standard, predictable rugby ball shape. However, the same theories used to calculate the shapes of these nuclei also predict an uneven distribution in mass for nuclei with particular numbers of protons and neutrons. These asymmetric pear-shaped nuclei are extremely short – lived, and until recently it was difficult to observe them experimentally. A technique developed at the ISOLDE radioactive beam facility at CERN has for the first time been able to successfully study the shape of some of these short-lived nuclei.
The experimental observation of these shapes is important for understanding the theory of nuclear structure. Pear-shaped nuclei are also important for more complex physics, such as potential use in the observation of electric dipole moments (EDMs) in atoms. The Standard Model predicts that these EDMs (the separation of positive and negative charges within atoms) are so small as to be unobservable, but new and refined theories state that they could be measurable. This could be a sign of new physics beyond the Standard Model.
CERN’s science and engineering needs have driven new technological advances in fields as diverse as medicine and computing. This year has seen the launch of a partnership between CERN and STFC, so that UK entrepreneurs and small businesses will be able to harness these advances and translate them into marketable services and products. The scheme, which is open to applications from entrepreneurs, research groups, or small start-up companies, provides an outstanding support package to five companies per year which includes funding for intellectual property protection and access to CERN and STFC expertise.
By bridging the gap between science and industry it is hoped that small high-tech businesses will evolve to become profitable companies.
For more information on any of these discoveries, and to find out what else has been going on at CERN, why not have a look at the website at http://home.web.cern.ch/.
STFC pays the UK contribution to the CERN budget as well as supporting UK participation in the four LHC experimental detector projects, including the Higgs boson detectors ATLAS and CMS, which will all undergo essential maintenance during the long shutdown. With nearly 600 UK scientists regularly working at CERN the UK has made major strategic investments in the LHC and the development of the experimental detectors and played a central role in much of the research that has taken place at the LHC in the last three years.