2007/07/31 by François Arleo, Francois Arleo, Thierry Gousset · 2 citations
Physics and Astronomy · #Gluon #HERA #High-Energy Particle Collisions Research #Large Hadron Collider #Nuclear physics #Particle physics #Particle physics theoretical and experimental studies #Parton #Perturbative QCD #Photon #Physics #Production (economics) #Proton #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Rapidity #hep-ph
paper · pdf · doi:10.1016/j.physletb.2007.12.025
published as Phys.Lett.B660:181-187,2008 · 14 pages, 6 figures. Typo corrected in Eq. (4)
openalex publication_date 2008/01/07 · arxiv created 2008/10/23 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The possibility to observe the nuclear modification of the gluon distribution at small-x (gluon shadowing) using high-p⊥ prompt photon production at RHIC and at LHC is discussed. The per-nucleon ratio, σ(p+A→γ+X)/(A×σ(p+p→γ+X)), is computed for both inclusive and isolated prompt photons in perturbative QCD at NLO using different parameterizations of nuclear parton densities, in order to assess the visibility of the shadowing signal. The production of isolated photons turns out to be a promising channel which allows for a reliable extraction of the gluon density, RGA, and the structure function, RF2A, in a nucleus over that in a proton. Moreover, the production ratio of prompt photons at forward-over-backward rapidity in p–A collisions provides an estimate of RGA (at small x) over RF2A (at large x), without the need of p–p reference data at the same energy.