Speaker
Description
Gravitational form factors (GFFs) encapsulate fundamental information about a hadron's internal structure including its mass distribution and mechanical quantities such as the pressure and shear forces. Recently, significant efforts have been made to access these GFFs experimentally and via ab initio lattice calculations. In this talk, I will focus on measurement of near-threshold $J/\psi$ photoproduction t-channel cross section which provides a unique tool to probe gluon GFFs of the nucleon. $J/\Psi$-007 experiment (E12-16-007) was conducted in Hall-C at the Thomas Jefferson National Accelerator Facility to measure near threshold 2-D $J/\psi$ exclusive photoproduction cross sections as a function of photon energy $E_{\gamma}$ and Mandelstam variable $t$. The experiment utilized a high intensity real photon beam produced by incidence of a 10.6 GeV incident electron beam on a copper radiator situated upstream of a hydrogen target. The produced $e^-e^+$ ($\mu^-\mu^+$) pair from decay of $J/\Psi$ was detected using two arm spectrometers in Hall C: the HMS and the SHMS. The bremsstrahlung photon energy range $E_{\gamma}$ and momentum transfer $|t|$, are between 9.1 GeV and 10.6 GeV and up to 4.5 GeV$^2$, respectively. I will focus on the recently published results on extracted gluon GFFs from the electron channel data. In addition, I will also present preliminary results from analysis of muon channel data and its impact on the uncertainties of the extracted form factors.
