The Particle Zoo: The subatomic world and the latest results from CERN

On the 17th November, some of our A-Level Physics students, together with Bentley Wood students, attended a lecture held at The Chemistry Auditorium, UCL, given by Dr Gavin Hesketh who works in their Department of Physics & Astronomy. With an auditorium full of keen physicists, Dr Hesketh gave us an insight into the world of current particle physics by describing it as an ‘interesting time’, because we somehow understand everything but nothing at the same time. Dr Hesketh explained the difficulty of particle physics because understanding the smallest entities does not necessarily provide answers for how the universe works as a whole.

There are many unexplained phenomena that exist, and we were introduced to a number of different theories that try to fill in the gaps in our knowledge such as Supersymmetry, String Theory and the existence of dark matter. With what is known as dark matter and dark energy comprising an estimated 95% of our universe, it may play a crucial role in explaining why galaxies are rotating much quicker than what we had expected them to. Evidence for dark matter is being found by looking out to the cosmos, and with technology only set to develop to a more advanced level, who knows what may be found in the coming years!

In relation to CERN, Dr Hesketh described how the Large Hadron Collider is being used to find new particles. For example, Higgs boson particles will only be produced once in every 10 billion proton collisions, so protons are collided 40 million times every second. This means that large amounts of energy are needed for these collisions, hence the increasing sizes of the accelerators, with the Large Hadron Collider being the largest particle accelerator in the world. We were shown data that had been collected over several years from the LHC. Through this, we learned that discovering a new particle was essentially a waiting game, with trends in data that may indicate a new particle eventually levelling off and disappointing the many eager theorists who had already written essays explaining a possible theory.

In late May 2017, word got out that the physicists at CERN had fast-tracked the plans to build a larger, more powerful, more expensive accelerator with the hopes that it will yield more results despite more room for research with the LHC. With plans to have the LHC feed off into the larger accelerator, chances are that not too much will change about the LHC as we know it today.

All in all, the lecture was very engaging and educational. It informed us on current discoveries from the LHC and the ever-developing theories that help us understand more about the universe. To conclude, we will leave you with a quote that Dr Hesketh mentioned during the lecture.

‘If you think you understand quantum mechanics, you don’t understand quantum mechanics’ –  Richard Feynman

Written by Eidi Hibro (HEHS) and Shreya Sunwar (Bentley Wood)