DARK MATTER

    

     As Dr. Akerib explains, “Overwhelming observational evidence indicates that most of the matter in the Universe consists of dark matter -- material unseen except for it's gravitational effects. One possibility is that the dark matter is Weakly-Interacting Massive Particles (WIMPs) that were produced in the early Universe. These relics could be in the Milky Way and be detectable through scattering off of atomic nuclei in a terrestrial detector.  The detecting of WIMPs is a great experimental challenge because they interact at a low rate with small energy depositions, amidst much higher sources of background.”

     Dr. Akerib will introduce the dark matter problem and the WIMP hypothesis, and he will discuss a range of the different techniques that he and his colleagues use in their attempts to detect them. These approaches include pucks of germanium operated at 50mK, buckets of liquified xenon instrumented with light-sensitive photomultiplier tubes, and the resurgence of bubble chambers from the heyday of accelerator-based particle physics.