Professor Laura Baudis, University of Zurich, discusses the nature of dark matter.
One of the major challenges of modern physics is to decipher the nature of dark matter. Astrophysical observations provide ample evidence for the existence of an invisible and dominant mass component in the observable universe. The dark matter could be made of new, yet undiscovered elementary particles, with allowed masses and interaction strengths with normal matter spanning an enormous range. Among these, weakly interacting massive particles (WIMPs), which froze out of thermal equilibrium with a relic density matching the observations, represent a well-motivated class of candidates. They could be directly observed via scatters off atomic nuclei in underground, ultra-low-background detectors, or indirectly, via secondary radiation produced when they pair annihilate. They could also be generated at particle colliders such as the LHC, where associated particles produced in the same process are to be detected. After an introduction to the dark matter problem and the phenomenology of direct dark matter detection, I will discuss the most promising direct detection techniques, addressing their current and future science reach, as well as their complementarity.