ATLAS detector in CERN

CERN: A Frontier in Science and International Collaboration

What is mass? What are the organising principles of our universe? What processes have given rise to our existence? These may seem like grand questions, but there is one place where they can seem quite mundane: the European Organisation for Nuclear Research, more commonly known as CERN. Located on the border between Switzerland and France, this world-leading particle physics laboratory is home to the largest particle accelerator in the world: the Large Hadron Collider (LHC). Protons circulating in the 27-kilometer-long collider are steered by strong magnets and progressively accelerated by electrical fields to nearly the speed of light. Two beams of protons going in opposite directions cross at four interaction points rigged with numerous detectors. This system allows physicist to peer into the quantum realm and observe complex processes only possible in extremely high energy environments, such as in the early universe.

“This world-leading particle physics laboratory is home to the largest particle accelerator in the world: the Large Hadron Collider (LHC).”

In 2012, the LHC experiments ‘ATLAS’ and ‘CMS’ confirmed the existence of a new elementary particle: the Higgs boson. The following year the Nobel Prize in Physics was jointly awarded to François Englert and Peter W. Higgs for their theoretical prediction of its existence. Their prediction was derived from ‘the Standard Model’, one of the most influential theories in particle physics. The discovery of the Higgs boson, almost 50 years after its existence was first proposed, represents a great victory for modern physics – demonstrating how our current theoretical framework can explain and predict the basic building blocks of matter.

However, this framework remains incomplete and only includes about five percent of the total contents of our universe. The rest is thought to be composed of dark matter and dark energy – substances that remains far beyond our understanding. Another phenomenon that has not been fully understood yet is matter and anti-matter asymmetry. Energy can produce matter, and when this happens the process is symmetric – a particle and an anti-particle are produced simultaneously. However, in our current universe there is much more matter observed than antimatter, otherwise they would meet and return back to energy. Hence, some asymmetric processes must have taken place in the early universe for us to be able to exist now. In order to interrogate the limits of these theories, scientists need to design experiments which push the boundaries of current technology.

“In 2012, the LHC experiments ‘ATLAS’ and ‘CMS’ confirmed the existence of a new elementary particle: the Higgs boson.”

CERN was founded in 1954 through the international collaboration of 23 member states in Europe and has been constantly developing and expanding ever since. Thanks to the devotion of scientists from all over the world, CERN is home to experiments at the forefront of particle physics and dedicated computing centers for storing and processing petabytes of experiment data. It is a truly unprecedented example of cross-border cooperation within the scientific community. In publications from CERN experiments, every contributor can be found in the multiple-page-long author list. Regardless of whether an individual has worked on the development of the experimental apparatus, developed software tools, or analysed the data itself, all work is acknowledged and considered to contribute directly or indirectly to the final results.

The UK is one of CERN’s member states and supports the organization both financially and academically. At the University of Oxford, more than 50 scholars and students work on the CERN project. A third-year D.Phil. student working on the ATLAS experiment, Migle Stankaityte, shared her research experience: “I work in a big analysis team of about 20 people from institutes all over the world. I present in the group meetings regularly and get insight on my work both from the members of the analysis team and my group at Oxford. At CERN I can directly work with people from institutions on the other side of the globe, which is incredibly useful and productive”. She is currently working on a challenging project attempting to observe an experimentally elusive phenomenon known as Higgs decay.

To support its ongoing search for insight into the rules that govern our universe, CERN is planning to upgrade both their particle accelerator and detectors in coming years. This, they hope, will allow them to make precise observations of experiments involving even higher energy collisions. The future collider proposed is expected to achieve the record-breaking collision energy – seven times greater than the current system. To achieve this, it needs to have a larger circumference (around 100 kilometres) and occupy a land area equivalent to New York City. If it is implemented, the cost is approximately 23 billion pounds in total.

“The future collider proposed (…) needs to have a larger circumference (around 100 kilometres) and occupy a land area equivalent to New York City.”

You might be shocked by those vast numbers and even skeptical about the value of such a huge scientific undertaking.  After all, particle physics experiments seem to be really detached from our life. In reality, however, the impact of such a science project is often significantly underrated. Though you might not realise, CERN has fostered a range of technologies that now appear in most corners of our life. For instance, it is actually the birthplace of World Wide Web. The English scientist, Tim Berners-Lee, created and wrote the first web browser in 1990 while employed at CERN. Another successful example is in medical science. The magnet technology derived from the hadron collider has been adopted in the gantry design for hadron therapy, as a kind of cancer treatments.

The techniques developed in the project are not exclusive – they can also be used to solve other physics questions. In August this year, scientists created a device to monitor the motion of underground structures at CERN. It is extremely sensitive and can pick up very small seismic motion. Researchers now have an idea to use it at the Advanced Virgo detector in the States, whose collaboration with LIGO won the Nobel Prize in Physics in 2017 for successfully detecting gravitational waves. The device may help filter out the noise due to seismic events to the minimum limit from the desired wave signal.

You may wonder whether the CERN base is confidential and isolated with so many cutting-edge technologies being developed but, on the contrary, it is open and lively. “I cycle to the work place every day and I absolutely love the amazing views of fields and mountains on my way”, Migle said. CERN is accessible and attracts millions of visitors each year. It is iconic not only because of its world-famous discoveries but how it achieves them. The history has witnessed so many scientific breakthroughs in the chase and race between groups or nations, such as in satellite launch and space exploration. CERN lights up a pathway, to unite individuals’ efforts and overcome the common challenge. That could be the silver bullet to some major problems in the next century, such as climate change.

The author would like to thank Migle Stankaityte for the interview and helps on this article, and Gabija Zemaityte for the liaison.

Image Credit: Migle Stankaityte