AdS/CFT for the early stages of heavy ion collisions

I give a brief introduction to the AdS/CFT correspondence targeted at heavy-ion physicists. I also review some insights to our understanding of the early stages of heavy-ion collisions coming from selected studies made using methods of the AdS/CFT correspondence.Comment: 8 pages, 4 figures. Plenary talk at the Quark Matter 2014 conferenc

QCD, diffraction and string theory

Recently, string theory on some specific curved backgroud spacetime geometries has been conjectured to be equivalent to certain gauge theories (AdS/CFT correspondence). This correspondence may be used to investigate the non-perturbative regime of gauge theories. I describe its application to the study of soft scattering amplitudes in a confining gauge theory. I describe two qualitatively different applications: amplitudes with vacuum quantum number exchange (Pomeron-like), amplitudes with Reggeon exchange. The last case requires going beyond eikonal approximation on the gauge theory side.Comment: 5 pages. Presented at the 10th International Workshop on Deep Inelastic Scattering, DIS2002, Krakow, Polan

The Lund Model at Nonzero Impact Parameter

We extend the formulation of the longitudinal 1+1 dimensional Lund model to nonzero impact parameter using the minimal area assumption. Complete formulae for the string breaking probability and the momenta of the produced mesons are derived using the string worldsheet Minkowskian helicoid geometry. For strings stretched into the transverse dimension, we find probability distribution with slope linear in m_T similar to the statistical models but without any thermalization assumptions.Comment: 12 pages, 2 .eps figures, footnotes added, results unchanged, version to be published in Phys.Lett.