William & Mary’s two-man team of Kostas Orginos and Andreas Stathopoulos is instrumental in a new U.S. Department of Energy initiative at the Thomas Jefferson Accelerator Facility (JLab) in Newport News.
Orginos, the Calkins-Ritter Professor of Physics, and Stathopoulos, professor of computer science, have key roles in the JLab component of SciDAC, or Scientific Discovery through Advanced Computing, according to Robert Edwards, senior staff scientist in the JLab Theory Group.
“We have budgeted a full PD (postdoc position) plus some additional personnel for each of the five years of the project to W&M,” Edwards wrote in an email message to Jeff Nelson, chair of William & Mary’s Department of Physics. “For the budget, we have to list project milestones and the lead person responsible for a project thrust. Kostas is one of our four leads, in this case, for a new method to (radically) improve the statistical averaging we use for measurements key to the JLab 12GeV and Electron Ion Collider programs.”
The JLab work is itself just one component of three joint projects funded by the DOE for the partnership between its Nuclear Physics and Advanced Scientific Computing Research groups. The DOE announced some $35 million in funding for the five-year project.
“The total budget for Kostas’s task is listed as $6M. Kostas is to lead over contributions from 7 of the 8 institutions,” Edwards wrote in his email to Nelson. “Kostas…is a Joint JLab/W&M staff member. Kostas and Andreas have close, close connections to JLab staff. It is through these strong connections that I have full confidence in the success of the project.”
Orginos is a member of the executive committee of the group USQCD — US Quantum Chromodynamics; Edwards is the chair. The group is devoted to using lattice quantum chromodynamics to solve the mysteries of the strong force, the interaction governing the quarks and gluons that make up the neutrons and protons in the nucleus of the atom.
Orginos explained that he, Stathopoulos and the rest of their SciDAC group are working on improving the calculations involved in QCD.
“The calculations we perform go under the name of Monte Carlo calculations,” he said. “It boils down to the computation of a very high dimensional integral. The guts of the calculation that we’re doing are stochastic; they involve random variables and our answers come out with uncertainties. So, our goal is to reduce the uncertainties on our final product.”
The calculations involve almost unimaginable amounts of data, which is where Stathopoulos and other computer scientists and mathematicians come in. The Orginos-Stathopoulos partnership dates back to 2007 and their work has regularly included post-docs, graduate students and even undergrads. Stathopoulos noted that the principles and skills students acquire in working on QCD questions with him and Orginos have applications beyond QCD and even far beyond physics.
“That’s the beauty of what we are working on,” Stathopoulos said. “It’s not only physics; it’s the computational part of physics. The students are learning valuable tools. Some of our students go on to work in the finance industry, making four times our salary.”
Orginos added that a student who worked with him and Stathopoulos on lattice QCD is now conducting unrelated work as a staff scientist at Lawrence Livermore National Lab.
“Do I know what kind of projects he’s working on?” Orginos asked. “He’s not allowed to tell me.”
Stathopoulos said his own involvement in their partnership began as a sort of mirror image of their students who took their acquired skills outside of the physics world.
“When we first started, I had no idea about physics — zero,” he said. “I was coming from the computer science, numerical mathematics point of view. I could develop algorithms for the computations required by the physics problems, but I didn’t understand the underlying physics problem at all.”
He added that, in the early days of the collaboration, he often started at the end of the project, taking on a computational problem that needed to be solved.
“And as time goes by, just by having more meetings and trying to understand the problem better, I can now address not just the end projects, but the main project itself,” he said. “Now, I can have algorithmic ideas that improve the entire project, not just pieces of it.’’
In addition to providing new generations of seasoned physics-literate computer scientists and physicists comfortable with advanced algorithms, the interdisciplinary Orginos-Stathopoulos partnership has attracted funding from the National Science Foundation as well as the Department of Energy.
“And that’s the cool thing,” Stathopoulos said. “Because what has been nice with this collaboration is not only do we improve the state-of-the-art in physics, but the new algorithms and software that come out of that are valuable throughout the community.”
Joseph McClain, Research Writer