European Grid Infrastructure (EGI) has released the third episode of Stories from the grid – an on-going series of mini documentaries. In this episode, we visit Marcel Vreeswijk and Hurng-Chun Lee to learn more about their research on top quark physics at NIKHEF, the Dutch National Institute for Subatomic Physics.

The top quark is the largest of the fundamental building blocks of the Universe. Together with the Higgs boson, it is one of the elementary particles being studied at the Large Hadron Collider (LHC), the world's largest and most complex scientific instrument. Particle physicists use the LHC to study variations from the Standard Model and potentially discover new laws of physics, governing everything from dark matter to extra dimensions. The particle known as the top quark is a window into this weird and wonderful world.

Marcel explains: “Top quark behaviour is predicted by the Standard Model of physics, but we expect to see deviations from this theoretical prediction in the experimental data from the LHC. And by studying these deviations, we can learn where the Standard Model is not so standard.”

“To put it simply, we have the experimental data, we know the predicted background values – so subtracting one from the other gives us the signal we are looking for.”


This is where grid computing is indispensable. In the video, Marcel and Hurng-Chun explain how customised grid computing workflows are key to filtering and sieving the massive sets of data down to a manageable size. Without these tools, it would be impossible to pick out the key results that could hold the clues to top quark behaviour.