More than 50 participants from around the world and from experiment and theory alike met in Patras for the 3rd Joint ILIAS–CERN–DESY Axion–WIMPs training workshop on 19–25 June. Josef Jochum of the University of Tübingen and Axel Lindner of DESY organized the meeting with Konstantin Zioutas of the University of Patras and CERN as chair. It provided stimulating talks with new results and much discussion.

A main focus was, naturally, on axions and other light particles coupled to photons. There were status reports and first results from the new generation of the "light shining through walls experiments" (ALPS, BMV, GammeV, LIPSS, OSQAR, PVLAS), which aim to detect such particles in the laboratory. These experiments direct a strong laser at an opaque wall and then search for photons on the other side. In the presence of a magnetic field, for instance, the laser photons could convert into axions which would pass through the walls before being reconverted into photons by the inverse process on the other side of the wall.

There were also results from the upgraded apparatus of the PVLAS collaboration, which last year seemed to have found indications for such a new particle in a polarization experiment. Now with an improved setup with better sensitivity and reduced systematic uncertainties, the collaboration is unable to confirm its earlier results. The CERN Axion Solar Telescope collaboration presented new bounds from searches for axion-like particles coming from the Sun. For the first time, these are better than constraints from the energy balance in helium-burning stars. Last, but not least, the meeting heard of progress in the Axion Dark Matter Experiment, which is searching for axions that could make up part or all of the dark matter in the universe.

Other dark matter candidates also featured prominently at the workshop. There was news from the searches for weakly interactive massive particles (CRESST II, EDELWEISS II and XENON 10) as well as from sky searches via X-ray and gamma-ray observations. Another way to gain new insights into fundamental physics is to test symmetries. On this front, there was a report on the cryoEDM experiment, which is searching for an electric dipole moment of the neutron; this would indicate a new source of CP violation.

On the theory side, participants heard about the wide variety of particles that can exist at low energies and that are predicted by extensions of the Standard Model, such as string theory and models with extra dimensions. Talks looked at what we can learn about the underlying fundamental theory by finding/constraining such particles, and what kinds of experiments are needed for the most efficient searches and how they can be improved. Although last year's results from PVLAS were the original motivation for many of the theoretical investigations, it became clear during the meeting that independent of this there is a huge discovery potential for new fundamental physics using low-energy experiments. In his talk just prior to the conference dinner, Dimitri Nanopoulos highlighted another important aspect of fundamental physics at low energies: the mystery of the dark energy that drives the accelerated expansion of the universe.

All in all it was an active meeting, with fundamental physics at low energies as an emerging theme. Searching for new particles and their interactions in small scale, low energy, high-precision experiments could prove to complement conventional accelerator physics in the search to discover the fundamental laws of nature.

• The next workshop will be at DESY in June 2008. For more details about the meeting in Patras see http://axion-wimp.desy.de.