QCD on the light cone and heavy ion collisions: the CGC, the Glasma and multi-gluon correlations

High energy heavy ion collisions are efficiently described as the collision of two sheets of Color Glass Condensate. The dynamics of the collision can be studied ab initio in a light cone effective field theory approach. Factorization theorems allow one to separate the initial state evolution of the wave functions with energy from the final state interactions that produce matter with high energy densities called the Glasma. We discuss how this matter is formed, its remarkable properties and its relevance for understanding thermalization of the Quark Gluon Plasma. We discuss multi-gluon correlations in the Glasma. In particular, long range rapidity correlations, reflected in a Glasma flux tube picture of the collision, are not washed out by subsequent final state interactions and may provide a sensitive probe of early time dynamics. A near side "ridge"-like structure observed in two particle correlation studies of central heavy ion collisions can be explained as resulting from radially flowing flux tubes.