New Directions in Physics Beyond the Standard Model

New York University, New York NY

Investigators

Abstract

This award funds the research activities of Professors Neal Weiner and Joshua Ruderman at New York University. The Standard Model (SM) of Particle Physics has been exceptionally successful in describing observed phenomena. However, a number of motivations exist for physics beyond the Standard Model, not the least of which is the existence of the dark matter which dominates the galaxies of the universe. Searches for new phenomena are now providing copious amounts of experimental data. In recent years the Large Hadron Collider has collected a sizable dataset derived from the scattering of elementary particles after they are accelerated to great speeds and made to collide. Likewise, new searches for dark matter have tested many of the predictions of the most popular theoretical models of dark matter. So far all of these results seem consistent with the SM, and decisive non-gravitational evidence for dark matter has not emerged. But much more data is coming. The LHC has just begun operating at even higher energies and anticipates collecting twice as much data in the next few years as was collected previously. Future axion-detection experiments will probe the possible existence of dark matter with masses near those of the heavier elementary particles already discovered (such as the famous Higgs boson), and diverse experiments are emerging to probe dark matter at lighter mass scales as well. Moreover, theoretical studies now are pointing to what the next generation of experiments should look like. Understanding the implications of ongoing experiments and where they are lacking will help place the US in a central position to uncover new physical laws and/or discover new particles. As a consequence, it is in the national interest to fund theoretical research that helps leverage our already sizable investments in experiment. In this context, where significant data has arrived but much more is yet to come, Professors Weiner and Ruderman will carry out a diverse research program in theoretical particle physics, one which stretches across multiple length scales in anticipation of multiple emerging datasets from experiments. This research will also have significant broader impacts. The PIs will create a Math for Physical Sciences Bootcamp lecture series for high-school students. They will also give public lectures, and will grant Physics in Media Fellowships to support the travel of journalism and film students to visit physics experiments that will appear in their stories and movies. More technically, the PIs will develop a range of new models of dark matter and particle physics, aimed at understanding what the search capacity for existing and planned experiments will be and to motivate new experiments. In particular, the PIs will study models of interacting dark radiation and their impact on measurements of the Hubble parameter. They will develop new models where dark matter is produced by exponential growth or oscillations. They will also develop new models of dissipative and self-interacting dark matter, and will study their impact on structure formation. They will develop ways to exploit astrometric lensing and axion star explosions in order to provide novel tests of dark-matter properties. They will also develop a systematic procedure for treating CP violation in SMEFT using invariant objects, and will deploy this procedure to study the size of CP violation imprinted by various UV completions. Finally, the PIs will respond to new data as it emerges to determine their theoretical implications. 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.