The Physics & Astronomy Colloquium Series presents Kevin Fossez of Florida State University, discussing "Broad Many-body Resonances, Non-Hermitian Quantum Mechanics, AI, and the Superheavy H Isotopes" on March 7.

Abstract: In low-energy nuclear physics, studying general properties of highly unstable many-body quantum systems has become critical, not only to test our understanding of nuclear forces and quantum chromodynamics in nuclei with an extreme proton-to-neutron ratio, but also to understand how the limits of nuclear stability, or drip lines, emerge. With the advent of rare isotope beam facilities around the world, and in particular the Facility for Rare Isotope Beams (FRIB) in the U.S., the exploration of the drip lines is about to accelerate. In the next few decades, thousands of new neutron-rich isotopes are expected to be discovered, many of which play a critical role in astrophysical events, whose properties will be in part dictated by their unstable nature.

In this talk, I will first introduce the physics of nuclear open quantum systems and the challenge posed by broad many-body resonances. Then, I will present new theoretical developments in the Gamow density matrix renormalization group method to handle the entanglement in unstable states, as well as a new AI-inspired technique to extrapolate resonances into the resonant regime. Finally,  I will show how these advances can help us tackle the superheavy hydrogen isotopes and other nuclear oddities.