Axions and WISPs

Bad Honnef Physics School

Th, 19.08.2021 18:30  –   Tu, 24.08.2021 14:00
Igor Garcia Irastorza (Zaragoza), Joerg Jaeckel (Heidelberg), Klaus Desch (Bonn)
Physikzentrum Bad Honnef
Hauptstr. 5, Hauptstr. 5, 53604 Bad Honnef, Germany

Contact person:
Dr. Victor Gomer (Physikzentrum Bad Honnef),


Scientific organizers:
Igor Garcia Irastorza (University of Zaragoza), Joerg Jaeckel (Universität Heidelberg), Klaus Desch (Universität Bonn)

August 19 - 24, 2021, Physikzentrum Bad Honnef, Germany

supported by





The school will take place in-person at the Physikzentrum Bad Honnef (PBH) unless Covid-19-situation should worsen significantly (currently infection rate in Germany and in the region is quite low). PBH has well established and carefully worked out hygiene concept for your safety. According to current regulations, participation in the school is possible for fully vaccinated or recovered persons as well as for those who have a negative Covid-19 antigen test less than 48h old.

Some lectures have to be given remotely due to travel restrictions for the lecturers. For participants, remote participation in the lectures will be possible if participants cannot travel to Bad Honnef due to the pandemic. In this case, a reduced fee applies.

We hope to see as many of you as possible in Bad Honnef!

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.

Lecturers and Topics:

  • Andreas Ringwald (DESY): Axion theory
  • Igor G. Irastorza (Zaragoza): Axion experiments
  • David J. E. (Doddy) Marsh (Göttingen): Axion cosmology
  • Javier Redondo (Zaragoza): Axion astrophysics
  • Felix Kahlhöfer (Aachen) ALPS at XENON1t + elsewhere
  • Paride Paradisi (University of Padova and INFN): "News from ALPs and g-2“
  • Torben Ferber (DESY) Axions and light particles at accelerators
  • Special lecture: Pierre Sikivie, Laureate of the Sakurai Prize 2020

The participants have the opportunity to present their own work during a poster session on Friday afternoon. This event will also serve to trigger discussions among the participants. Two blocks of exercise classes will take place Saturday and Sunday afternoon.

⇒ Schedule

FEES: 200 € full board and lodging (for DPG* members 100 € )
* The German Physical Society (DPG)