PhD defence by Luuk Vermunt: Hadronisation of heavy quarks
On May 16, 2022, Luuk Vermunt has successfully defended his thesis and received his doctorate with the distinction Cum Laude. Luuk studied Experimental Physics in Utrecht and finished his PhD at the Institute for Gravitational and Subatomic Physics (GRASP). The defense has taken place in the Senaatszaal of the Academiegebouw before an examining committee and his paranymphs, family, friends and colleagues and could also be followed online.
Summary PhD thesis
Hadronisation of heavy quarks; Production measurements of heavy-flavour hadrons from small to large collision systems
Particle physicists are in a sense some extreme historians; with our experiments we try to reproduce and understand the conditions of the universe a few microseconds after the Big Bang. Matter looked very different at the time, the temperature and density were so extremely high that quarks and gluons (the elementary particles that are confined in protons and neutrons in our current universe) could move freely in the so-called quark-gluon plasma. The ALICE experiment, located at the Large Hadron Collider (LHC) at the Swiss research institute CERN, aims to unravel the properties of this plasma, to get a better view of how this state of matter has influenced the evolution of the universe.
The quark-gluon plasma that we can create at CERN lives so extremely short that it is impossible to observe directly. The plasma 'evaporates' almost immediately into thousands of different (measurable) particles. Using the data from these particles, we try to reason back how the plasma behaved. Some types of particles are more interesting than others. In this dissertation, the focus is on particles composed of one charm quark and one or more lighter quarks (a charm hadron).
A good understanding of the process of how the (theoretically interesting) charm quark forms an (experimentally measurable) charm hadron is fundamental. This process cannot be calculated from the underlying theory, so it introduces a dependency on phenomenological models. This thesis presents four different experimental analyses with the ALICE experiment that are compared with predictions from different phenomenological models, resulting in significant constraints in the freedoms of these models.
Promotor: prof. dr. R.J.M. Snellings
Co-supervisors: dr. A. Mischke †and dr. A. Grelli