Electroweak Interactions and Fundamental Symmetries in Effective Field Theories

Atoms are composed of the positively charged nucleus and negatively charged electrons. The nucleus itself is made up of protons and neutrons. The properties of nuclei are an important aspect of our understanding of the universe, such as big bang nucleosynthesis or stellar evolution.

In addition, experiments with nucleons can inform us about the fundamental forces that exist in nature. Nucleons, however, are composite particles themselves built from elementary particles called quarks and gluons and have therefore a finite size. This feature complicates the modeling of the nuclear interaction and of the determination of uncertainties that are important to interpret possible disagreements between theoretical calculations and experiments.

This project will use a tool called effective field theory to calculate how nuclear systems interact with the weak and electromagnetic interaction and provide predictions for a number of important experimentally relevant observables. Effective field theory is one tool that can provide reliable uncertainty estimates and it will be used to reduce uncertainties on a number of important observables. This work will thereby also improve our understanding of the nuclear interaction.

This project aims at improving the understanding of electroweak processes using effective field theory (EFT). EFT is a systematic expansion in a ratio dictated by a system-inherent scale separation. The PI will use two EFTs, the EFT for short-range interactions (SREFT) and chiral EFT (CEFT).

The PI and his collaborators will calculate structure functions for the 3-nucleon system using SREFT and CEFT. In turn, that will allow for improved predictions for nuclear corrections to the hydrogen spectrum that will be used to connect atomic physics experiments with nuclear physics properties. With the SREFT the PI will consider electric dipole moments (EDM) and try to understand how the Coulomb interaction and finite range effects impact the EDM form factors.

Here, SREFT provides a guide to understanding the renormalization/uncertainties for such a calculation that, through experiments, can provide possible insights into features of physics beyond the standard model.

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.