Axions and WISPs

Bad Honnef Physics School

19 Aug - 24 Aug 2021


Physikzentrum Bad Honnef

Scientific organizers:

Dr. Igor Garcia Irastorza, University of Zaragoza, Spain • Prof. Dr. Joerg Jaeckel, Universität Heidelberg • Prof. Dr. Klaus Desch, Universität Bonn

This school has been postponed from August 2020 to August 2021 due to the corona pandemic.

Over the last decade there has been a remarkable renaissance in the search for axions and other light particles. The axion, a hypothetical fundamental particle, was originally predicted by Wilczek and Weinberg as a consequence of the Peccei-Quinn mechanism that explains a severe puzzle related to the theory of the strong interaction, QCD. While QCD conceptually allows for the presence of CP violation in the strong interaction, no such CP violation (e.g. through a neutron dipole moment) has ever been observed, putting unnaturally strong constraints on value of the corresponding free parameter. Axions, if existing, are automatically produced in the early universe and are an interesting candidate for cold dark matter. Several generalizations of the axion idea, ALPs (axion-like particles) or WISPs (weakly interacting slim particles) are motivated by theory and/or inspired by unexplained astrophysical anomalies.

Theoretical model building has shown that such very light and very weakly interacting particles are a common feature of fundamental extensions of the Standard Model and have been argued to provide a resolution to important open questions such as the nature of dark matter. In parallel experimental efforts have increased, new ideas have been developed and many new experiments are being realized. Overall the field is in a process of rapid development and expansion. Therefore, the time is right to hold a Bad Honnef Physics School targeted on the next generation of axion experimentalists and theorists.

The school aims at providing solid foundations to those who want to start working in the field while rounding the overview for those already engaged in aspects of axion research, experimentally or in theory. The school is targeted at Master and PhD level students as well as young postdocs either already working in the field or just interested in this emerging hot topic.