May 2021
The life and death of the Higgs particle
“When the Higgs particle was discovered at CERN in July 2012, it was a scientific sensation. Since then, we have succeeded in studying its properties further – but it still poses many mysteries.
In my research, I use a new theoretical model to understand how Higgs particles are created from two gluons or decay back into them. The theoretical understanding of these and other processes in turn helps us to simulate and interpret corresponding experiments on large accelerators. The big question behind this is: does the Higgs particle behave as predicted by the standard model of particle physics? Or does it show anomalies that point to previously unknown physics?
©: Angelika Stehle
What sounds like a simple production or decay process is not easy to describe theoretically, as strong interaction effects play a role. In an intermediate step, “virtual quarks” are created that only exist during the process but cannot be measured experimentally.
I use a new approach based on an effective field theory: the so-called Soft Collinear Effective Theory. With SCET, I can break down the process into individual components. These factors in turn can be calculated most easily on a specific energy scale, whereby this scale varies from factor to factor. At the end, all factors are brought together again.
Although we know that such a factorization theorem must exist in our case, we do not know the individual proportions and it is precisely these that we need to find out. The SCET method is the first to allow sufficiently precise analytical calculations. This is a highly topical research subject that has only really picked up speed in recent years due to its complexity. Being at the forefront of this is incredibly exciting.”
Marvin Schnubel is a PhD student in Professor Matthias Neubert's group and holds a PhD fellowship at the Mainz Physics Academy. He is fascinated by the idea of theoretically understanding processes that are omnipresent around us.