A proton’s identity as a particle called a baryon may reside with a Y-shaped gluon structure (yellow) at the center the particle, rather than its two up quarks (u) and one down quark (d). If that’s true, a collision can separate the quarks from the junction, and the baryon number. New quarks and antiquarks will appear out of the vacuum to accompany the freed quarks and gluons.
Valerie A. Lentz/Brookhaven National Laboratory