paper / alexeyguzey / Jun 11
The authors present a theoretical framework (GγA–FONLL) for calculating diffractive D⁰ meson photoproduction in ultraperipheral Pb–Pb and p–Pb collisions at the LHC, using nuclear diffractive parton distributions with leading twist shadowing and corrected photon fluxes. They specifically quantify the coherent diffractive contribution that is rejected by the Xn0n neutron-tagged event selection used in the first LHC measurement of D⁰ photoproduction in Pb–Pb collisions, and extend the model to p–Pb UPCs where photon–proton scattering dominates.
diffractive-photoproductionultraperipheral-collisionsheavy-ion-physicslhc-physicscharm-physicsquantum-chromodynamicshep-ph
“Diffractive D⁰ photoproduction in ultraperipheral Pb–Pb collisions can be calculated within the GγA–FONLL framework using nuclear diffractive parton distributions from the leading twist shadowing approach.”
paper / alexeyguzey / Jun 11
The VALO1.0 analysis presents new parton distribution functions (PDFs) for real photons determined from a global QCD fit to photon structure function F2^γ data from e+e- scattering, at both LO and NLO. By using Monte Carlo replica methods, the authors propagate experimental uncertainties into the PDFs, yielding robust quark distributions at both orders and a well-constrained gluon at NLO (though LO gluons remain largely unconstrained). The resulting photon PDFs are released publicly alongside the γEKO evolution code and VALOfitter framework, and broadly agree with existing parameterizations while establishing a baseline for future fits incorporating photoproduction data.
high-energy-physicsquantum-chromodynamicsparton-distribution-functionsmonte-carlo-simulationsphoton-structure-functionhadron-like-ansatz
“VALO1.0 provides both LO and NLO photon PDFs determined from a global QCD analysis of F2^γ data from e+e- scattering.”
paper / alexeyguzey / Jun 11
This review focuses on nuclear parton distribution functions (PDFs), particularly in the small-x regime where nuclear shadowing is prominent. It synthesizes experimental evidence and theoretical models explaining these modifications, alongside model-agnostic PDF extractions that support collinear factorization and leading-twist dominance. Future research directions include precision studies at the LHC and the upcoming Electron-Ion Collider.
high-energy-physicsparton-distribution-functionsnuclear-shadowingquantum-chromodynamicsparticle-physicsnuclear-theory
“Nuclear parton distribution functions (PDFs) are significantly modified in the small-x region due to nuclear shadowing.”
paper / alexeyguzey / May 14 / failed