A trio of physicists at William & Mary are participating in two of the five topical theory collaborations in nuclear physics recently announced by the U.S. Department of Energy.

DOE is funding the $11.24 million, multi-institution initiative, announcing the goal is to “bring together leading nuclear theorists to collaboratively focus on solving challenging problems central to advancing knowledge in nuclear physics.”

“Advances in nuclear physics provide important new insights into the nature of our world as well as novel applications in the areas of national security, energy, health and space exploration,” said Timothy Hallman, associate director of science for nuclear physics at the Department of Energy. “Developing rigorous theoretical frameworks to underpin such advances enables new predictions of nuclear phenomena and a foundation for understanding how knowledge gained can be used to benefit society, such as exploring more clean energy options and new applications in nuclear medicine and industry.”

Assistant Professor Christopher Monahan and Professor Kostas Orginos are co-investigators on the Quark-Gluon Tomography Collaboration. Their specific project is titled “3D quark-gluon structure of hadrons: mass, spin and tomography” and includes Wally Melnitchouk and David Richards, staff scientists at the U.S. Department of Energy’s Thomas Jefferson National Accelerator Facility who are adjunct professors at W&M.

“Protons and neutrons are the basic building blocks of almost all visible matter, and account for 95 percent of the mass of the visible universe,” Monahan said. “Protons and neutrons are composed of smaller particles, quarks, bound together by the strong nuclear force, which is carried by gluons and is responsible for all nuclear matter, from hydrogen ions to neutron stars.”

He explained that the exact arrangement of quarks and gluons inside protons and neutrons is not well known, and this project will help understand the three-dimensional arrangement of gluons within protons and neutrons. Monahan said William & Mary will receive $104,500 in funds to support a graduate student.

“The student will work jointly with Kostas and myself and will analyze numerical data to determine the three-dimensional structure of protons and neutrons from first principles,” Monahan said. “In particular, the student will analyze results from computations using lattice quantum chromodynamics — the theory of the strong nuclear force that binds together quarks and gluons — carried out on large-scale supercomputers.”

Jozef Dudek is the principal investigator on a William & Mary subgrant that is a component of a $1.8 million grant based at Indiana University titled “Coordinated Theoretical Approach for Exotic Hadron Spectroscopy.”

Dudek, the Sallie Gertrude Smears Spears Associate Professor in William & Mary’s Department of Physics, noted that William & Mary will receive around $400,000 in DOE funding.

“The W&M funds are to be used to half-support, for four years, a new faculty member in the physics department who will work on topics of relevant to the topical collaboration,” Dudek said. He added that a search is underway, and he hopes to have a new physicist start in fall of this year.

Dudek explained that while the quarks and gluons of quantum chromodynamics can bind together to form the protons and neutrons of the atomic nucleus, they can also arrange themselves in exotic combinations – these are the focus of study for the new collaboration. Candidate states have been observed in experiments, and more are being sought in the GlueX and CLAS12 experiments at the Thomas Jefferson National Accelerator Facility in Newport News.

, Research Writer