Researchers at Argonne National Laboratory used a Department of Energy supercomputer to map the internal structure of a pion with greater precision than ever before. The team published their findings in the Journal of High Energy Physics.
Pions are subatomic particles that mediate the strong nuclear force, the fundamental interaction holding atomic nuclei together. Understanding their structure provides insight into how quarks and gluons organize within these particles and how they behave under extreme conditions.
The supercomputer simulations used lattice quantum chromodynamics, a computational approach that models quark and gluon interactions on a discrete spacetime grid. This method allows researchers to calculate properties that cannot be directly measured in experiments. The team performed calculations with unprecedented precision by using refined computational grids and running extended simulations across thousands of processor cores.
The detailed internal maps reveal how quarks and gluons distribute their momentum and spin within the pion. These distributions affect how pions interact with other particles and influence processes occurring in neutron stars and early universe conditions. Previous calculations lacked the computational power to resolve these internal details with confidence.
Argonne's supercomputer capabilities were essential for this work. The facility houses some of the world's fastest machines, capable of performing quintillions of calculations per second. Without this computational infrastructure, achieving the precision required for these calculations would be impractical.
The research advances the field of hadronic physics by providing theoretical predictions that experimentalists can test using particle accelerators. Collaborations at facilities like Thomas Jefferson National Accelerator Facility are actively measuring pion properties, creating opportunities to compare theoretical predictions with experimental data.
Limitations remain. Simulations still operate under approximations, including the omission of certain quantum effects and the use of artificial boundary conditions. Computational costs also constrain how much the researchers can refine their calculations. Despite these constraints, the work demonstrates how supercomputing enables