Special Particle Physics Seminar: Gluons in Nuclei: From Near-Threshold J/ψ to universality

Abstract:

The quark structure of nuclei has been studied extensively over the past four decades, yielding transformative insights into how nuclear interactions modify the structure of bound nucleons. In contrast, much less is known about the gluonic structure of nuclei, even though gluons carry much of the momentum and dynamics that bind quarks together. 

In this talk I will present new measurements of near- and sub-threshold J/ψ photoproduction off light nuclei, which provide the first direct access to the gluonic structure of bound protons and uncover surprising evidence of enhanced gluon distributions in high-virtuality nucleons. I will then place these results in the broader context of short-distance nuclear structure, showing how the dynamics of correlated nucleons can drive universal modifications of quark and gluon distributions in nuclei. Together, these advances point toward a consistent description of atomic systems across scales—from quarks and gluons to nucleons. This work was recently highlighted as one of Physics World’s Top 10 Breakthroughs of 2024.
 

Seminar Organizer: Dr. Igor Korover