2024/03/13 by V. Guzey, Guzey, V., M. Strikman +1
Engineering · Physics and Astronomy · #Crystallography and Radiation Phenomena #FOS: Physical sciences #Geophysical Methods and Applications #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph) #Nuclear Experiment (nucl-ex) #Nuclear Physics and Applications
paper · pdf · doi:10.48550/arxiv.2403.08342
openalex publication_date 2024/03/13 · openalex created_date 2024/03/15 · openalex updated_date 2026/08/01
Using the leading twist approach (LTA) to nuclear shadowing, we calculate the ratios of diffractive and usual parton distributions for a heavy nucleus (Pb) and the proton, RA/p=(fi/AD(3)/fi/A)/(fi/pD(3)/fi/p), for coherent and summed (coherent plus quasi-elastic) nuclear deep-inelastic scattering. We find that RA/p ≈ 0.5-1 for quarks as well as for the ratio of the diffractive and total cross sections [(dσ\rm diff/dMX2)/σ\rm tot]eA/[(dσ\rm diff/dMX2)/σ\rm tot]ep and RA/p ≈ 0.5-1.3 for gluons in a broad range of x, including the kinematics of the Electron-Ion Collider, which reaffirms the difference from the nuclear enhancement of RA/p predicted in the gluon saturation framework. We demonstrate that the magnitude of RA/p is controlled by the cross section of the interaction of hadronic fluctuations of the virtual photon with target nucleons, which explains an enhancement of RA/p in the color dipole model and its suppression in LTA. We argue that the black disk limit corresponds to RA/p=1 and R\rm cohA/p=0.86 for the summed and coherent scattering, respectively. Relying on an intuitive definition of the saturation scale, we show that the ratio of the saturation scales of a heavy nucleus and proton QsA2(b)/Qsp2(b) ≈ 1 at small impact parameters b due to the strong leading twist nuclear shadowing and diluteness of the nuclear density.