Coherent $J/\psi$ electroproduction on ${}^4$He and ${}^3$He at the Electron-Ion Collider: probing nuclear shadowing one nucleon at a time

Abstract

While the phenomenon of gluon nuclear shadowing at small $x$ has been getting confirmation in QCD analyses of various LHC measurements involving heavy nuclei, it has not been possible so far to establish experimentally the number of target nucleons responsible for nuclear shadowing in a given process. To address this issue, we study coherent $J/\psi$ electroproduction on ${}^4$He and ${}^3$He in the kinematics of a future electron-ion collider and show that this process has the power to disentangle the contributions of the interaction with a specific number of nucleons $k$, in particular, with two nucleons at the momentum transfer $t\ne 0$. We predict a dramatic shift of the $t$-dependence of the differential cross section toward smaller values of $|t|$ due to a non-trivial correlation between $x$ and $k$. This calculation, which makes use for the first time of realistic wave functions, provides a stringent test of models of nuclear shadowing and a novel probe of the 3D imaging of gluons in light nuclei. In addition, thanks to this analysis, unique information on the real part of the corresponding scattering amplitude could be accessed.

7 pages, 7 figures, Supplemental Material. Final published version

References in corpus (4)

• J/Psi production in ultraperipheral Pb+Pb and p+Pb collisions at energies available at the CERN Large Hadron Collider
• Transverse nucleon structure and diagnostics of hard parton-parton processes at LHC
• Accessing transverse nucleon and gluon distributions in heavy nuclei using coherent vector meson photoproduction at high energies in ion ultraperipheral collisions
• Nuclear suppression from coherent $J/\psi$ photoproduction at the Large Hadron Collider

Cited by in corpus (1)

• 50 Years of Quantum Chromodynamics