Lattice gauge theory provides the framework to study the excited spectrum of hadrons. As such, this project will help unravel key aspects of the physics of quark confinement and hadron formation in quantum chromodynamics, the theory of the strong interactions and one of the fundamental forces of Nature. In fact, understanding the physics of confining gluons is an important intellectual challenge and was recognized as one of the seven so-called Millenium Prize problems announced by the Clay Mathematics Institute of Cambridge, Massachusetts. The masses of excited hadron resonances will be evaluated using Markov-chain Monte Carlo computer simulations of quarks and gluons on a space-time lattice. Results of these calculations are relevant to several ongoing experimental programs, such as the Hall B N* program and the GlueX experiment in Hall D at the Thomas Jefferson National Accelerator Facility. It is worth mentioning that in the past such calculations were performed with unrealistically large quark masses due to computational limitations. The current project continues the development of a new methodology to incorporate crucial multi-hadron operators into computations in order to reduce the quark masses to nearly their physical values.
The proposed research incorporates the participation of two graduate students, and possibly one or more undergraduate students, so the broader impact of this project concerns also the training of future researchers in the field of lattice QCD. The students are provided with an unique opportunity to learn and contribute to an important line of inquiry at the forefront of nuclear theory. Given the high-performance aspects of this projects, students will also acquire essentials skills in the use of state-of-the-art parallel computing resources. The broader impacts of the proposed activities will be strengthened by posting results with simplified background information on publicly accessible web pages.
