Investigate the Standard Model using the power of exascale computing

August 17, 2022 — Thanks to a powerful new ability to probe the smallest known particles, understanding of the nature of matter throughout the universe could be about to take a big leap forward.

Andreas Kronfeld, a theoretical high-energy physicist at Fermi National Accelerator Laboratory, leads the ECP LatticeQCD subproject.

Scientists will use calculations made possible by exascale computing to create high-fidelity simulations of the atomic nucleus to reveal the organization of matter and its interactions at the subatomic level. As a result, answers to difficult questions in nuclear and high energy physics could be revealed, including the most fundamental of all: what is the universe made of?

“Humans have always been curious about how the world around them works,” said Andreas Kronfeld, a high-energy theoretical physicist at the US Department of Energy’s (DOE) Fermi National Accelerator Laboratory, or Fermilab, where particles are propelled at near the speed of light to collide with each other. “We like to think that’s what sets us apart from other life forms on planet Earth. We wonder about these things.

Kronfeld is principal investigator of the LatticeQCD subproject within the DOE’s Exascale Computing Project. LatticeQCD is a high-energy and nuclear physics effort to understand fundamental laws of nature and, perhaps, help uncover evidence of new particles and new laws of nature in the process.

Addition to the standard model

Besides the commonly known electrons, protons, and neutrons, atoms are also composed of other particles, such as quarks, muons, mesons, bosons, leptons, and photons. The Standard Model of particle physics contains all of these and eight more, but scientists believe there are more.

“We have to think there are other particles in the Standard Model,” said Kronfeld, who has studied particle physics at Fermilab for more than three decades. “It is the basis of all experimental programs in particle physics. But we need a lot of very fast computers to figure it all out.

Enter exascale computing. It could provide the power that LatticeQCD project algorithms need to simulate the nucleus of an atom to discover particles that might underlie known elementary particles. Thus, by capitalizing on the exascale, LatticeQCD promises to better understand fundamental matter at the subatomic level.

Additional Particle Tips

An area of ​​primary interest in the subatomic domain, for example, is that of muons. They have a charge and generate tiny magnetic fields as they spin like a top. The force emanating from the phenomenon is known as the magnetic moment. Physicists want to identify what influences magnetic fields and how muons interact with quarks and gluons in order to test the Standard Model of particle physics.

Measurements so far suggest there is something in the universe that scientists haven’t had the computing power to identify. Because the strong interactions between quarks and gluons account for almost all of the mass in the visible universe, understanding them is essential to explaining the universe.

At the DOE’s Oak Ridge National Laboratory, Frontier recently became the first supercomputer to break the exascale barrier, delivering 1.1 exaflops of performance and surpassing the target threshold of one quintillion calculations per second. The system will allow researchers to develop technologies critical to the country’s energy, economic and national security missions, helping solve problems of critical importance to the nation that lacked realistic solutions just five years ago.

“We can do this – measure quarks and gluons – but we need a lot of computers to do this,” Kronfeld said. “To calculate the quark-gluon impact on the magnetic moment of the muon, you have to calculate at about half a percent uncertainty. It’s only been in the last few years that we’ve had the high-performance computing power to be able to come up with something really interesting. But we need more precision, and to solve this problem we need exascale computers.

Test calculations demonstrate capability

Kronfeld thinks the magnetic moment is exciting because it implies that particles outside the Standard Model but contributing to the magnetic moment have been excluded from the calculations, and the exascale calculation could provide answers.

The LatticeQCD team designed six test calculations to demonstrate the capability of the exascale calculation. Kronfeld said these tests can be directly generalized to a wide variety of different physical problems in nuclear and high-energy physics, deepening and broadening knowledge about the fundamental properties of matter, space and time.

If cracks exist in the standard model, the coming years of exascale computing should reveal them. “Whether our calculations and the experiments of our colleagues are up to the task depends on what nature has to tell us,” Kronfeld said.

About this research

This research is part of the DOE-led Exascale Computing Initiative (ECI), a partnership between the DOE Office of Science and the National Nuclear Security Administration. The Exascale Computing Project (ECP), launched in 2016, brings together research, development, and deployment activities as part of an exascale computing ecosystem capable of ensuring sustainable exascale computing capability for the nation.

Source: Lawrence Bernard, Exascale Calculation Project

Sherry J. Basler