33 RD I NTERNATIONAL COSMIC RAY CONFERENCE,RIO DE JANEIRO 2013 THE ASTROPARTICLE PHYSICS CONFERENCE Dark Matter 2013 MARC SCHUMANN. Albert Einstein Center for Fundamental Physics, University of Bern, Switzerland marc.schumann@lhep.unibe.ch Abstract: This article reviews the status of the exciting and fastly evolving field of dark matter research as of summer 2013, when it was discussed at ICRC 2013 in Rio de Janeiro. It focuses on the three main avenues to detect WIMP dark matter: direct detection, indirect detection and collider searches. The article is based on the dark matter rapporteur talk summarizing the presentations given at the conference, filling some gaps for completeness. Keywords: ICRC2013, dark matter, direct detection, indirect detection, collider searches, WIMP. 1 Introduction The existence of dark matter is one of the stongest indica- tions that there must be physics beyond the standard model of particle physics. Numerous indirect observations at as- tronomical and cosmological scales [1], complemented by results of complex many-body simulations [2], point to the presence of a new form of matter in the Universe, which only interacts significantly via gravity. The most famous observational evidence is the rotation profiles of galaxies, the dynamics of galaxy clusters, the separation of dark and light matter in galaxy clusters, and the interpretation of the cosmic microwave background (CMB). Recently the Planck satellite mission [3] has published new and precise mea- surements of the CMB, which are in full agreement with the predictions of the ΛCDM model, describing a cosmos dominated by dark energy (Λ) and cold dark matter (CDM). The new values for the energy densities from Planck are Ω CDM = 0.268 and Ω Λ = 0.683, see Fig. 1. Figure 1: The latest results from the Planck satellite [3] on the energy densities attributed to dark energy, dark matter and ’ordinary’ baryonic matter. Even though dark matter makes up a sizeable fraction of the energy density of the Universe, and outnumbers ’ordi- nary’ baryonic matter by a factor 5, the particle(s) which constitute the dark matter remain unknown as of today. The absence of electromagnetic and strong interactions makes it experimentally ’dark’, however, interactions at the weak scale might be possible. Many theories beyond the standard model predict particles which are neutral, cold (i.e. non- relativistic), and stable (or have half-lifes longer than the age of the Universe). These are viable dark matter candi- dates, with the most prominent being the neutralino χ 0 in supersymmetric theories [4], the lightest Kaliza-Klein par- ticle (LKP) in theories with extra-dimensions [5], or the lightest T -odd particle in little Higgs models [6]. All are excellent examples of weakly interacting massive particles (WIMPs) [7], which are stable as their decays are prevented by some new symmetry. The search for the dark matter particle has become one of the most exciting topics in Astroparticle Physics, and tremendous progress is made on experimental and theo- retical research. For this reason, this year’s ICRC confer- ence in Rio de Janeiro (“The Astroparticle Conference”) featured, for the first time, a full branch dedicated to dark matter. This article is the attempt to summarize the main conclusions of the talks and posters presented at this occa- sion, complemented with some extra information added by the author. At this occasion, the author wants to apologize to all contributors to the ICRC 2013 dark matter session, whose work could not be mentioned in this highly-biased summary. The article contains three sections addressing the differ- ent methods to detect WIMP dark matter: by searching for signs of WIMPs scattering in low-background detectors (direct detection, Sect. 2), by looking for WIMP annihila- tion products (indirect detection, Sect. 3), and by searching for WIMPs produced in particle colliders such as the LHC (Sect. 4). The approaches are largely complementary and it is widely assumed that a convincing dark matter signal should be seen by more than one. We do not even attempt to provide detailed descriptions of the various experiments, but mainly focus on the underlying concepts and the recent results, and refer the reader to the references for further information. The article closes with a short section on more exotic (here: “non-WIMP”) dark matter models and a con- clusion. 2 Direct Detection It has been pointed out by Goodman and Witten [8] in 1985, that the signature of WIMPs scattering in a detector medium might be directly detectable by sensitive instruments [9], provided that the WIMP interacts not only gravitationally with ordinary matter but with weak-scale cross sections. Another prerequisite is that there is dark matter in our local solar neighborhood, which is assumed to be the case as confirmed by various astronomical studies [10]. The arXiv:1310.5217v1 [astro-ph.CO] 19 Oct 2013