Lectures on Diffraction and Saturation of Nuclear Partons in DIS off Heavy Nuclei
Abstract
The Lorentz contraction of ultrarelativistic nuclei entails a spatial overlap and fusion (recombination, saturation) of partons belonging to different nucleons at the same impact parameter. In these lectures we present a consistent description of the fusion of partons in terms of nuclear attenuation of color dipole states of the photon and collective WeizsäckerWilliams (WW) gluon structure function of a nucleus. The point that all observables for DIS off nuclei are uniquely calculable in terms of the nuclear WW glue amounts to a new form of factorization in the saturation regime. We start with the theory of multichannel propagation of color dipoles in a nuclear medium including the colorsinglet to coloroctet to coloroctet transitions. We show how the GlauberGribov formulas are recovered from the multichannel formalism. Then we derive the twoplateau momentum distribution of final state (FS) quarks produced in deep inelastic scattering (DIS) off nuclei in the saturation regime. Then we comment on the signatures of saturation in exclusive diffractive DIS. A large body of these lectures is on the recent theory of jetjet inclusive cross sections. We show that for hard dijets the decorrelation momentum is of the order of the nuclear saturation momentum $Q_A$. For minijets with the transverse momentum below the saturation scale we predict a complete disappearance of the azimuthal jetjet correlation. We conclude with comment on a possible relevance of the decorrelation of jets to the experimental data from the STARRHIC Collaboration.
 Publication:

arXiv eprints
 Pub Date:
 December 2002
 DOI:
 10.48550/arXiv.hepph/0212161
 arXiv:
 arXiv:hepph/0212161
 Bibcode:
 2002hep.ph...12161I
 Keywords:

 High Energy Physics  Phenomenology;
 High Energy Physics  Experiment;
 Nuclear Experiment;
 Nuclear Theory
 EPrint:
 The notes of lectures presented by N.N.N. at the XXXVI St.Petersburg Nuclear Physics Institute Winter School on Nuclear and Particle Physics &