Has HERA reached a new QCD regime?

Abstract

These notes are a summary of our efforts to answer the question in the title. Our answer is in the affirmative as: (i) HERA data indicate a large value of the gluon structure function; (ii) no contradictions with the asymptotic predictions of high density QCD have been observed; and (iii) the numerical estimates of our model give a natural description of the size of deviation from the routine DGLAP explanation. We discuss the alternative approaches and possible new experiments.

29 pages, 37 figures in eps files

References in corpus (32)

• Unitarization of the BFKL Pomeron on a Nucleus
• The Renormalization Group Equation for the Color Glass Condensate
• Relating different approaches to nonlinear QCD evolution at finite gluon density
• Parton Saturation at Small x and in Large Nuclei
• Solution to the evolution equation for high parton density QCD
• Saturation and Universality in QCD at small x
• Structure function of the nucleus in the perturbative QCD with $N_c\to \infty$ (BFKL pomeron fan diagrams)
• Measurement of the Proton Structure Function F_2 at Very Low Q^2 at HERA
• Toward Equilibration in the Early Stages After a High Energy Heavy Ion Collision
• HERA Collider Physics
• Diffractive Dissociation Including Multiple Pomeron Exchanges in High Parton Density QCD
• Diffractive parton distributions from the saturation model
• Measurement of diffractive photoproduction of vector mesons at large momentum transfer at HERA
• Unitarity and the QCD-improved dipole picture
• Scale Anomaly and "Soft" Pomeron in QCD
• Nonperturbative Gluon Radiation and Energy Dependence of Elastic Scattering
• Charm production at HERA
• The QCD description of diffractive processes
• An estimate of higher twist at small x and low Q^2 based upon a saturation model
• Predicting F2D(3) from the dipole cross-section
• Measurement of Di-jet Cross-Sections in Photoproduction and Photon Structure
• Shadowing Corrections and Diffractive Production in DIS on Nuclei
• Higher twists and maxima for DIS on nuclei in high density QCD region
• Screening Corrections in Photo and DIS Production of $J/\Psi$
• The Components of the ${\gamma }^{\ast }{\gamma }^{\ast }$ Cross Section
• The dipole picture of small x physics (a summary of the Amirim meeting)
• Scaling Violations in the $Q^2$ Logarithmic Derivative of $F_2$
• Higher Twist Corrections and Maxima for DIS on a Proton in the High Density QCD Region
• $\bar{d}-\bar{u}$ asymmetry and semi-inclusive production of pions in DIS
• Structure Functions in Deep Inelastic Lepton-Nucleon Scattering
• Total ${\gamma }^{\ast }$ p Cross Section
• Low-x Physics

Cited by in corpus (13)

• A Modification of the Saturation Model: DGLAP evolution
• A Linear Evolution for Non-Linear Dynamics and Correlations in Realistic Nuclei
• Signatures of the Color Glass Condensate in J/Psi production off nuclear targets
• Scattering of Dark Particles with Light Mediators
• Summing Pomeron loops in the dipole approach
• Gluon saturation effects on J/Psi production in heavy ion collisions
• J/Psi production in heavy ion collisions and gluon saturation
• QCD Saturation in the Semi-classical Approach
• Heavy Quark Photoproduction in k_T Factorization Approach
• Deep Inelastic Scattering at the TeV Energy Scale and the LHeC Project
• Unitarity Corrections to the Drell-Yan Process in the Target Rest Frame
• Unitarity Corrections to the Proton Structure Functions through the Dipole Picture
• Gluon saturation effects on J/Psi production in heavy ion collisions