Grant: Subatomic Physics Envelope - Individual

Eighty-four percent of matter in our Universe defies explanation within the Standard Model (SM) of particle physics. And yet, this dark matter (DM) is vital to our understanding of the formation of the Milky Way and physics in our galactic neighbourhood. I will develop theoretical extensions of the SM and experimental proposals to unveil the nature of DM, including its mass, interactions with SM particles and evolution in the early universe. My long-term goal is to accelerate the discovery of DM by exploring three distinct and highly complementary directions, namely: 1) Accelerator searches for DM that interacts strongly with familiar matter. Accelerator experiments with a proton or lepton beam striking a thick target produce a large number of exotic secondary particles. These particles offer a unique opportunity for testing DM models that have been unexplored thus far. In the short-term I will study the cosmological history of such DM models, identify the parameter space where they can account for all of DM and investigate their experimental signatures at thick target experiments, paying particular attention to near-term efforts like the proposed DarkQuest experiment at Fermilab. 2) Using integrated photonics to search for DM with feeble couplings to familiar matter. If DM has a mass near the electron-volt scale it can potentially be converted to optical photons. I will show for the first time that integrated photonics (devices with sub-micron-scale features used to guide and manipulate light) can be used to search for DM in this mass range. My short-term goal is explore how specific periodicity and symmetry properties of these devices can be used to optimize DM conversion to light and estimate their sensitivity to DM. Ultimately, I will collaborate with experimentalists to propose a realistic search. 3) Theory and observation of the spatial matter distribution to probe DM that interacts only gravitationally with SM particles. I will confront the possibility that DM interacts with familiar matter only through gravity. My short-term goal is to explore such DM models and determine their behavior at small (sub-Galactic) distance scales. I will show that recently-proposed observational techniques for measuring the DM distribution using highly-magnified extra-Galactic stars will provide a powerful probe of these DM models. In the long run, I will collaborate with astrophysicists to develop an observational program that will yield unprecedented insights into the creation of DM and its microphysical properties. This research is important to physicists hunting for DM, and to the general public interested in the origin of DM and in the early universe. As my group progresses toward our short-term objectives, my trainees will not only gain expertise in particle physics and cosmology, but also develop valuable skills in problem-solving, programming, and data analysis - skills applicable in both academic research and industry.