Eur. Phys. J. A (2003) 18: 437-440
https://doi.org/10.1140/epja/i2002-10254-x

High-density QCD and saturation of nuclear partons

¹ Institut f. Kernphysik, Forschungszentrum Jülich, D-52425, Jülich, Germany
² Institute of Mathematics, Novosibirsk, Russia
³ L.D. Landau Institute for Theoretical Physics, Chernogolovka, Russia
⁴ NORDITA, Blegdamsvej 17, DK-2100, Copenhagen Ø, Denmark
⁵ Institute for Theoretical and Experimental Physics, Moscow, Russia

^* e-mail: N.Nikolaev@fz-juelich.de

Abstract

We review the recent finding of the two-plateau momentum distribution of sea quarks in deep inelastic scattering off nuclei in the saturation regime. The diffractive plateau which dominates for small p measures precisely the momentum distribution of quarks in the beam photon, the rôle of the nucleus is simply to provide an opacity. The plateau for truly inelastic DIS exhibits a substantial nuclear broadening of the momentum distribution. Despite this nuclear broadening, the observed final-state and initial-state sea quark densities do coincide exactly. We emphasize how the saturated sea is generated from the nuclear-diluted Weizsäcker-Williams because of the anti-collinear splitting of gluons into sea quarks.