antiquark

Models made different predictions for how the ratio of down and up antiquarks should change as you count antiquarks that carry more energy.

Then, a decade later, another group saw hints of puzzling variations in the down-to-up antiquark ratio.

Yet Miller calls this rival model “descriptive, rather than predictive,” since it’s tuned to fit data rather than to identify a physical mechanism behind the down antiquark excess.

When the “NuSea” experiment at Fermilab measured the down-to-up ratio as a function of antiquark momentum in 1999, their answer “just lit everybody up,” Alberg recalled.