Scaling in ${\gamma }^{\ast }p$ total cross sections, saturation and the gluon density

Abstract

Including the new HERA data, the ${\gamma }^{\ast }p$ total cross section is analysed in the generalized vector dominance/colour-dipole picture (GVD/CDP) that contains scaling in $\eta =(Q^2+m_0^2)/{\Lambda }^2(W^2)$, where ${\Lambda }^2(W^2)$ is an increasing function of $W^2$. At any $Q^2$, for $W^2\to \infty$, the cross sections for virtual and real photons become identical, ${\sigma }_{{\gamma }^{\ast }p}(W^2,Q^2)/{\sigma }_{\gamma p}(W^2)\to 1$. The gluon density deduced from the colour-dipole cross section fulfills the leading order DGLAP relationship. Evolution à la DGLAP breaks down for $η\lsim 0.1$.

15 pages, Latex using epsfig, 6 figures using 8 ps files

Cited by in corpus (18)

• S-Matrix Unitarity, Impact Parameter Profiles, Gluon Saturation and High-Energy Scattering
• Geometric scaling in diffractive deep inelastic scattering
• The Color Dipole Picture of low-x DIS: Model-Independent and Model-Dependent Results
• The Color Dipole Picture and the ratio of R(W, Q) = sigma L/sigma T
• Color Dipole Picture of Deep Inelastic Scattering, Revisited
• The energy dependence of the saturation scale in DIS at low x
• J/Psi photo- and electroproduction, the saturation scale and the gluon structure function
• Diffractive production and the total cross section in deep inelastic scattering
• The total virtual photoabsorption cross section, deeply virtual Compton scattering and vector-meson production
• Deep inelastic scattering and "elastic" diffraction
• On Ultrahigh-energy Neutrino Scattering
• The color dipole picture of low-x DIS
• Physical limits in the Color Dipole Model Bounds
• Comment on "The New F_L Measurement from HERA and the Dipole Model"
• Saturation in DIS at low x
• From Static Potentials to High-Energy Scattering
• Nuclear transverse momentum imbalance in the color dipole approach at the LHC regime
• On the Color Dipole Picture