Speaker is Kirsten Tollefson, associate professor in the MSU Department of Physics and Astronomy and a Collider Detector at Fermilab (CDF) team co-leader: What we’re trying to find is something that’s very rare, so we’re expecting one of these single top quarks in about 20 billion collisions of protons and anti-protons at this giant particle accelerator in Chicago. So there’s first of all only one place in the world that can make these top quarks and we have two experiments that live across the ring, this accelerator ring, from each other and partly we’re doing cross-checks of each other. [Aerial photo of Fermilab accelerator, then video of Fermilab particle detector installation.]
We work on the same kinds of physics processes but we use slightly different technologies and it’s independent scientists on each one. So we use similar techniques to look at similar types of physics processes, but with completely independent cross-checks, different sets of data and different manpower. So this is one way, when we are looking for something that’s one in 20 billion, you can make sure you have actually found what you thought you were looking for.
MSU is unique in that its one of the few universities in the world that’s on both these two experiments and in fact is the only university that has colleagues or professors that were working on searching for the single top on both the experiments. So, myself and Dr. Schwienhorst have been working on this for three or four years.
Speaker is Reinhard Schwienhorst, assistant professor in the MSU Department of Physics and Astronomy and DZero research team co-leader: This all happens at Fermilab in principle, but for us it’s not just a lot of resources that we need in terms of working with people and having different people all contributing, but it’s also resources on the intellectual side -- working with Professor Yuan from Michigan State who guided us in how exactly we should analyze the data and exactly what we should look for. [Graphics of two single top quart events: the DCF team’s particle collision event display, then the DZero team’s graphic of a proton-antiproton collision.] And also using computing resources, the computer cluster we have here at Michigan State, which we use both to prepare samples for this analysis and to also do the final analysis, but really also running on computer clusters all over the world.
[Photo of an MSU-built component of the Large Hadron Collider at CERN in Switzerland.] Several of us here at Michigan State are actually involved in doing the follow-up analysis of exactly this single top search at the LHC at CERN, so we’re looking forward to not just understanding what it is, but really going beyond it and understanding top quarks at a much, much deeper level at the LHC.
Speaker is Chien-Peng Yuan, professor in the MSU Department of Physics and Astronomy and a particle physics theorist: We are all familiar with the Einstein equation E=MC2, and we know about C – the speed of light -- and people know about Special Relativity, and also that we know about the energy. However we really don’t know about the mass -- M. And the whole object of the electroweak symmetry breaking has to do with the understanding of this mass. Where does this mass come from? [Fermilab animation illustrating 3-D view of aftermath of particle collisions.]
And the reason that the top quark is so heavy, as heavy as what we call the vacuum expectation value, which has the deep connection to the mass generation, is still unknown and that’s a very important question. Once we know about that, then we could then go back to understand the whole evolution of the universe that’s described today by the Standard Model, and plus some additional things such as dark matter we have not yet found.
Speaker is Jorge Benitez, doctoral candidate in the MSU Department of Physics and Astronomy and a key researcher on the DZero team: Being involved with a discovery is something unique that doesn’t happen to every grad student, so I’m very excited that I was involved with this project, and I’m happy that everything came out the way it did.
[Videography and production by Mark Fellows, Department of University Relations]
[Additional video, animation and photos courtesy of Fermilab, Batavia, Ill.]