Introduction to the topic
Particles from the Universe
Our Universe is filled with cosmic rays, gamma rays, neutrinos and with the hypothetical Dark Matter (DM) particles, which shape galactic environments, whole galaxies and the large-scale structures. The topic Matter and Radiation from the Universe addresses the question of the origin and nature of these particles and their role in the evolution of the Universe at different length and energy scales. Energetic cosmic rays, photons and neutrinos are the messengers of the ubiquitous high-energy phenomena in the Universe and form together the non-thermal Universe. To understand this important component of the cosmos we need to study the nature of cosmic accelerators, how matter and radiation interact under extreme conditions and how particles propagate over cosmic distances. On larger scales, a dark universe is revealed, where structures from the size of galaxies up to the entire Universe are shaped by the gravitational interaction of DM and massive neutrinos. To understand the role of these weakly interacting particles as cosmic architects, we have to measure the mass scale and mass hierarchy of neutrinos, and we have to detect or constrain Dark Matter particles, either directly in a detector on Earth, or indirectly through their annihilation or decay products in astrophysical objects.
Common research in a wide and diverse field
A common research in all the above mentioned areas is of major relevance in order to achieve a coherent picture of the evolution of our Universe ranging from galactic objects to the largest structures in the Universe. In our topic we utilise cosmic messengers of all types, i.e., cosmic rays, gamma rays and neutrinos, to understand how nature accelerates particles to very-high energies and how matter and radiation propagates over cosmic distances. With cosmic messengers detected by air shower arrays, neutrino and gamma-ray telescopes, we want to explore the fundamental laws of nature and search for New Physics in extreme cosmic environments and at energies beyond LHC energies. We want to measure the neutrino mass with the dedicated experiment KATRIN and neutrino mass hierarchy at the South Pole and to unambiguously detect DM particles in cryogenic bolometers in underground laboratories and through indirect measurements of DM annihilation with cosmic messenger instruments.
Enormous energy scales
The energy scales being investigated within our topic are enormous and span more than 20 orders of magnitude. They range from very low energies at the meV-scale (neutrino masses) and the keV-scale (direct DM detection) through the GeV and TeV scale (gamma-ray astronomy) up to the highest energies of 1015–1020eV (neutrino-astronomy and ultra-high energy cosmic rays). Our experimental methods are thus quite diverse and tailored to specific energy ranges. Theoretical efforts span over the whole topic with direct connections to the various experimental results, and there is a close cooperation of experimentalists and theorists on modelling experimental data.
Major progress in all fields
Recent years have seen major scientific results and breakthroughs as well as technological progress in all areas. Results achieved with large arrays of gamma-ray instruments like H.E.S.S., MAGIC and VERITAS, neutrino observatories like IceCube, and large air shower arrays like the Pierre Auger Observatory have revealed surprising results, documenting a rich discovery potential with cosmic rays, cosmic gamma rays and neutrinos. In neutrino physics the KATRIN design of combining a high luminosity tritium source with a huge electrostatic filter will enable major progress in neutrino mass sensitivity, and low background cryogenic bolometers for the EDELWEISS and EURECA/SuperCDMS experiments will do likewise in the search for DM particles.
KIT and DESY
As leading institutions Helmholtz groups from KIT and DESY are crucial to the success of experiments in our topic. KIT and DESY play leading roles in the design, prototyping, commissioning and/or long-term operation of large facilities at KIT (KATRIN, KASCADE-Grande), underground laboratories (EDELWEISS, EURECA/SuperCDMS) and at remote locations (Pierre Auger Observatory in Argentina, IceCube at the South Pole) and for future research infrastructures like CTA. For all research directions, relevant experimental technologies are further developed in the PoF 3 period, and advanced simulation packages such as CORSIKA and KASSIOPEIA are provided to a large user community.