BSM-PM: Theory and Simulation for Beyond Standard Model Tests in Antihydrogen Experiments

The PI, graduate, and undergraduate students will provide theoretical support for the experimental search for asymmetry between matter and antimatter by the ALPHA collaboration. The current understanding of the laws of physics predict perfect symmetry between matter and antimatter which is in tension with the observation that the universe is almost universally composed of matter. Any difference between hydrogen and its antimatter counterpart, antihydrogen, would challenge our understanding of the universe. The PI, graduate, and undergraduate students will perform calculations of basic processes in the ALPHA experiment to improve the precision of measurements of antihydrogen leading to more stringent tests matter/antimatter symmetry. In addition to the insights about fundamental physics, this project is an ideal training ground for theoretically minded graduate and undergraduate students. All students develop their own programs to explain different aspects of the ALPHA experiment and present their results to other scientists and the general public. They perform all tasks of physics research, growing as scientists in the process. This research project will provide theoretical and computational support in the experimental search for differences between the hydrogen atom and its antimatter counterpart, antihydrogen, by the ALPHA collaboration. Basic theoretical principles predict that the properties of hydrogen and antihydrogen are identical except for some trivial sign changes. Several properties of the hydrogen atom have been measured to extraordinary levels of precision. The goal is to reach this same level of precision in antihydrogen measurements, enabling high precision tests of matter/antimatter symmetry. While this is fundamentally an experimental undertaking, theoretical and computational treatments of the ALPHA experiment increase the precision and accuracy of measured properties of antihydrogen. In addition, the simulations help improve the experiment. The PI, graduate, and undergraduate students will focus on simulating basic processes in the experiment including laser cooling, non-linear stochastic heating of antihydrogen, predictions of spectra in strong fields, and sympathetic cooling of plasmas. During this project’s time frame, we will greatly improve the antihydrogen measurements by increasing the number of trapped antihydrogen by more than 10X through improving the plasma conditions in the experiment. These improvements will lead to: at least 10X improvement in the spectral precision of the 1S2S transition, the ability to measure other transitions (e.g. 2S-2P or 2S-4P) for an independent determination of the antiproton radius and antihydrogen Rydberg constant, improved measurement of gravity on antihydrogen using ideas from non-linear dynamics, and precision measurement of the 1S hyperfine splitting. Antihydrogen synthesis, trapping, and measurements lie on the boundaries between atomic, plasma, and experimental particle physics and it cannot be studied properly without using tools from all these fields. 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.