The Proton Has Been Lying to Us, and Apparently the Gluons Were in Charge the Whole Time
For most of my life, I was told that a proton was a relatively simple little thing. It contained two up quarks, one down quark, and enough scientific confidence to make the rest of us feel as though the matter had been settled. Draw three colored circles inside a larger circle, add a few labels, place the illustration in a textbook, and congratulations: you have explained one of the fundamental building blocks of the universe. Except, as usual, the universe neglected to consult the illustration. Physicists working with data from the STAR detector at Brookhaven National Laboratory’s Relativistic Heavy Ion Collider have found evidence that an important part of a proton’s identity may not belong to its three main quarks after all. It may instead be carried by a hidden, Y-shaped configuration of gluons connecting those quarks. In other words, the particles we casually describe as “glue” may not merely hold the proton together. They may be carrying the proton’s identification papers. I find...
