PARTICLES AND COSMOS · Particle Physics and cosmology: The interface

Final Activity Report Summary - PARTICLES AND COSMOS (Particle Physics and Cosmology: the Interface)

With the coming LHC era and the many astro/cosmological experiments being deployed, we are entering a period of extraordinary promise in fundamental science. Prologue experiment and the rapid expansion of theoretical knowledge in recent years tells us that the time is ripe for revolutionary discoveries that address some of the deepest questions needing answers in order for us to reach the next, beyond the Standard Model (SM), level of understanding of the fundamental laws of nature and the cosmos. These fundamental questions to be answered by a deeper theory of nature are: What is the origin of the electroweak scale? What explains the hierarchy of masses and couplings? What is the dark matter of the universe? What explains the predominance of matter over anti-matter in our universe? Can the inflation paradigm be embedded in the theory of elementary interactions? This implies that particles and cosmology must be investigated simultaneously. Indeed, at present there is emerging a new, interdisciplinary field of research which combines cosmology, astrophysics and particle physics. The theoretical tools are effective quantum field theories, symmetries including supersymmetry, extra space dimensions and new strong interactions. The objectives of this project were to face the above challenges at the interface of particle physics and cosmology at the training and research level. The Chair for Theory of Elementary Particles and Interactions, University of Warsaw, has very strong expertise in particle physics and the objective was to extend its competence in cosmology and astrophysics and to contribute significantly to the research on the challenging questions listed above. Those goals have been successfully reached. There have been organized 7 workshops with many lectures by leading scientists and talks by young researchers. Many speakers from abroad were invited to give talks at weekly seminars on particles and cosmology and on elementary interactions. 14 foreign specialists were employed in Warsaw for at least two months each (72 months altogether) and close collaboration with them of the members of the host has been established as well as they delivered very extensive training and transfer of knowledge activities. 9 Polish physicists have spent more than 50 months altogether as scientific visitors at CERN in Geneva, Max-Planck-Institut in Munich and Institute of Astroparticles and Cosmology in Paris. The successful training in cosmology and astrophysics enabled the Warsaw group to extend its research profile. The research has been focused on investigating the potential of beyond the SM theories for answering simultaneously the particle physics and cosmological questions and on studying experimental signatures of those theories. Here are several examples. Dark matter candidates and their phenomenological properties have been studied in theories that can explain the electroweak symmetry breaking. In supersymmetric theories one obtains then also interesting constraints on the mechanism of supersymmetry breaking and on the mechanism of baryogenesis via leptogenesis. Inflation and reheating after inflation have been investigated in supergravity theories. The pressing question of the (meta)stability of the vacuum in supersymmetric theories and of the cosmological vacuum selection has been studied. The obtained results support the expectations that the outstanding particle physics and cosmology questions can be simultaneously answered in a consistent theory based on such theoretical concepts as supersymmetry or extra dimensions and that its experimental signatures should be observed in the coming generation of experiments.

Data: CORDIS, © European Union