RUI: Theories of Dark Matter and Baryogenesis Confront Experiment

This RUI award funds the research activities of Professor David Tucker-Smith at Williams College. Despite its spectacular successes, the Standard Model (SM) of particle physics fails to address certain questions of fundamental importance. The SM has nothing to say about the nature of dark matter, a mysterious component of our universe that has played a crucial role in its evolution. Nor does the SM shed light on matter-antimatter asymmetry: if the SM were the whole story, virtually identical quantities of particles and antiparticles produced by the big bang would have annihilated each other nearly completely, leaving too little behind to form the structures around today (galaxies, people, and so on). In his work, Professor Tucker-Smith will explore theories of dark matter and matter-antimatter asymmetry, with a focus on understanding how these theories can be tested at existing and planned experiments. Research on these topics advances the national interest by promoting the progress of science in an essential direction: learning about the makeup of our universe and the physical laws that govern it. Significant broader impacts of this project will come from undergraduate involvement. By engaging in this research, Williams College students will learn important ideas, results, and methods relating to particle physics and cosmology. They will also develop broadly applicable skills through activities that will include computer programming, statistical analysis, manuscript preparation, and oral presentation of research findings. In more technical terms, Professor Tucker-Smith will conduct research in physics beyond the Standard Model along the following four directions. First, he will develop and study freeze-in baryogenesis models in which dark matter interacts with the Standard-Model Higgs particle. Second, he will perform detailed Monte Carlo studies of the collider phenomenology of electroweak-charged "portal" particles that appear in freeze-in baryogenesis models and many others. Third, he will assess how Lyman-alpha forest surveys and other cosmological observations constrain scenarios with multiple non-cold dark-matter particles. Finally, he will carry out a comprehensive study of a model of electroweak baryogenesis in which dark matter plays a central role in asymmetry generation. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.