Professor Dr. HARVEY B. MEYER

Harvey Meyer was appointed Tenured Professor for Theoretical ParticlePhysics at the Cluster of Excellence PRISMA, Department of Physics,Mathematics and Computer Sciences of the Johannes Gutenberg Universityin Mainz in April 2014. His research area is strong interaction physics,with an emphasis on hadronic contributions to low-energy precision observables and on the properties of strongly interacting matter a tnon-zero temperature and density, making use of large-scale lattice QCD simulations.

In order to discover physics beyond the Standard Model, some experiments are carried out at the highest energies, others aim at the highest precision. In that case, it is essential to bring the effects of strong interaction physics under control, which requires input from theory. Examples of such precision observables are the anomalous magnetic moment of the muon and form factors of the nucleon. With this line of research Harvey Meyer contributes to PRISMA's research area C "Structure of Matter".

The properties of strongly interacting matter are also fascinating in their own right. In a hydrogen atom, the electron starts unbinding from the proton at about 150'000 degrees Celsius. The core of the Sun,where nuclear fusion takes place, is about 100 times hotter. To "melt" a proton into quarks and gluons, roughly 100'000 times the core temperature of the Sun is needed. Such a high temperature was only present in the Universe in the first few microseconds after the Big Bang. Nonetheless the properties of hot quark matter had an influence on the subsequent evolution of the Universe.

Professor Meyer has significantly contributed to the understanding of the properties of hot quark matter. The latter can be characterizedlargely by the same concepts and methods used to study the properties of ordinary gases, liquids and solids. Due to its quantum andrelativistic nature however, the properties of hot quark matter do not correspond completely to either of these three categories. Instead it is a strongly coupled "plasma". Since the system is strongly coupled, Professor Meyer has used non-perturbative Monte-Carlo simulations to quantify these properties. He compares the results of such calculations to experimental studies of the quark-gluon plasma. In these experiments at particle colliders (RHIC, LHC, and in the future FAIR) the enormous temperature is achieved very briefly by smashing two heavy nuclei together at high energies (typically, gold or lead). Fortunately the reactions appear to be so fast that the system has time to equilibrate to a plasma before falling apart.