- Broida 3302
- Physics Special Seminar
Far from being quickly and simply resolved, the discovery in 1933 of anomalous dynamics in galaxy clusters has evolved into one of the richest fundamental problems in physics today. Indeed, this "dark-matter problem" provides arguably the strongest evidence we have of phenomena beyond the Standard Model of particle physics. Accordingly, experiments searching for direct evidence of dark matter over the past thirty years have voraciously developed deeper and deeper sensitivity at breakneck pace. The rapid pace at which experimental sensitivity has improved has been made possible by particle detectors utilizing liquid xenon, and I will describe two such world-leading experiments: the now-completed LUX experiment, and the upcoming LZ experiment, currently under construction. Experiments like these have primarily targeted the Weakly Interacting Massive Particle (WIMP), which is an attractive dark-matter candidate that simultaneously addresses anomalies on the largest scales in the universe---dark matter---and the smallest scales---electroweak naturalness. However, with the continued non-observation of the WIMP in dark-matter searches, and with no sign of electroweak naturalness in particle colliders, the attractiveness of the WIMP has waned in recent years. In response, much attention in the theoretical community has shifted towards alternative solutions to dark matter, in particular, hidden sectors of new physics whose dark-matter candidates have masses in the range of keV to GeV. This shift has spawned the beginnings of a new arms race among experimentalists to invent and develop future technologies that will be capable of probing these new interesting regions of parameter space. I will discuss strategies needed to search for these new candidates and introduce two promising experiments.