Particle Physics

Posted on: 10/07/2019

On 2nd April 2019, Year 12 physics students visited UCL in order to participate in a masterclass on Particle physics and learn about the particle behind the property of mass – the elusive Higgs boson. Professor Jon Butterworth introduced us to the 3 elementary particles that make the Standard Model in Physics; going into detail about Hadrons, Bosons (exchange particles) and Fermions as the fundamental building blocks for everything. Fermions have two groups- Leptons (the lightest particles) and quarks (which combine to form Hadrons). ATLAS Dr Ben Waugh then went into detail about the ATLAS detector, which discovered the Higgs Boson.

is one of the seven particle detector experiments constructed at the Large Hadron Collider, a particle accelerator at CERN in Switzerland and is one of the largest and most complex scientific instruments ever constructed. ATLAS is located at Interaction Point 1 of the Large Hadron Collider (LHC). It is a general-purpose particle physics experiment run through international collaboration and is designed to exploit the full discovery potential and the huge range of physics opportunities that the LHC provides.

 Dr Waugh then demonstrated a piece of software called HYPATIA that allows physicists to see what the ATLAS detects. We explored some data and tried to understand and identify electrons (as well as positrons), muons (and anti-muons), photons, neutrinos, and other more complicated particles – hadrons like the proton - that are often produced in form of “jets”.

Dr Rafi then took the stage and discussed photon therapy and how photons help with cancer research. One key point of the presentation was about Tumour Evaluation showing how cells mutate into tumours and the tumours spread around the body. She then went through three cancer treatments, which are chemotherapy, radiotherapy and phototherapy. Chemotherapy are drugs which kill dividing cells by damaging the part of the cell’s control centre that makes it divide. Other drugs interrupt the chemical processes involved in cell division. Radiotherapy (Radiation therapy) uses highenergy particles or waves, such as x-rays, gamma rays, electron beams, or protons, to destroy or damage cancer cells. Radiation works by making small breaks in the DNA inside cells. Phototherapy uses UV light, which uses two photons to kill cancer cells in the skin. The drug passes through the blood to reach cells throughout the body. When these cells are then exposed to UVA light, the drug is activated, killing them.

After a short break, we came back energised and ready to analyse a specific group of data set to using the HYPATIA software. We analysed up to 50 particle collisions (events) to try to find heavy neutral particles e.g. 2-boson or Higgs boson. First, we identify particles and look at each of the particle footprint visualisations, which then could allow us to identify the visualisation. After students analysed live events from Atlas, the data was then uploaded and plotted to show similarities and differences.

For the last activity of the day, we along with 3 others schools from Europe participating in the workshop, joined a Skype call with professors at CERN to discuss our findings and results. Sameer and I were chosen by Dr Waugh to represent England. Once the discussion was over, we were then able to ask questions about the ATLAS project at CERN. The conference finished at 3:30 p.m. and then everyone thanked the people involved in the workshop.


Shania Doughty - Sixth Form