New Tools to Study Strong Interaction Physics

点击翻译按钮获取中文摘要

The accepted theory of the strong nuclear force that holds atomic nuclei together, called QCD (Quantum Chromodynamics) has been known for 35 years, but is extraordinarily difficult to use and is poorly understood in precisely the regions where it is most prominent; for example, we know that protons and neutrons (collectively, "nucleons") are made of smaller constituents named quarks and gluons, but exactly how they are assembled into nucleons remains murky at best. In this grant, Belitsky and Lebed will use a variety of high-powered mathematical tools, often ones borrowed from string theory, to make headway in this complicated landscape. Belitsky is an expert in the theory of generalized parton distributions, which are the most precisely defined observables possible for nucleons, while Lebed is an expert on large Nc QCD, in which solving QCD becomes paradoxically simpler to solve by adding more degrees of freedom than occur in nature. In addition, Belitsky has become adept in a powerful technique called integrability, in which QCD and similar theories can be mathematically related to the physics of systems like ferromagnets and other "spin-chains". Meanwhile, Lebed is studying "holographic QCD," which is based upon an idea from string theory, that QCD and related strongly-interacting theories can be related to weakly-interacting gravity on a curved space. Each of Belitsky and Lebed will mentor a Ph.D. student in these project areas.