From Pentaquarks to the Proton's Matter Structure: Novel Insights from J/ψ-007*

Heavy quarkonium production offers a unique avenue to probe the gluonic structure of the nucleon. In the 12 GeV era, the latest generation of experiments at Jefferson Lab employs near-threshold J/ψ production to delve into topics such as the matter structure of the proton, the dynamic origins of its mass, and the hidden-charm pentaquarks first observed by LHCb.

I will present new findings from the J/ψ-007 experiment conducted in Hall C at Jefferson Lab. I will discuss the latest updated results regarding the search for LHCb hidden-charm pentaquarks, including a first look at our combined J/ψ → ee and J/ψ → μμ datasets. I will then focus on our determination of the proton's gluonic gravitational form factors based on our 2-D J/ψ cross section measurement from our J/ψ → ee dataset, which we recently published in Nature. Remarkably, our results suggest the existence of a dense, energetic core within the proton, localized at a substantially smaller radius than the proton's electric charge radius. I will follow this with new results from our combined J/ψ → ee and J/ψ → μμ datasets, including a preliminary analysis of the pressure and shear forces of the gluonic fields in the proton.