Nucleus-nucleus scattering in the perturbative QCD

by Mikhail Brown (St. Petersburg University, Russia)

Tuesday 11 Nov 2003, 14:00 → 15:00 Europe/Zurich

40-S2-B01 (CERN)

Nucleus-nucleus interaction is studied in the framework of the perturbative QCD in the high-colour limit and with a fixed coupling constant. The pomeron tree diagrams are summed by an effective field theory. The classical field eqations reduce to the non-linear BFKL evolution equation, which can easily be solved numerically. The resulting nuclear gluon densities are found to scale with the "saturation momentum" which grows with 1/x as a power. The nuclear structure functions are found to grow with 1/x as log square. For nucleus-nucleus scattering the field equations are solved by iteration procedure, which is found convergent in a restricted domain of not too high energies and atomic numbers. The found gluon distributions do not scale, have their maxima close to 2 GeV independent of rapidity and fall towards the central rapidity region. The cross-sections slowly grow with energy due to the contribution from peripheral collisions, where evolution remains linear. Simple variational estimates at higer rapidities confirm this tendency.

Organiser(s): Yiota Foka and Urs Achim Wiedemann
More information: http://home.cern.ch/a/alicedoc/www/chic/

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