Andrei Leonidov

Nonlinear gluon evolution in the color glass condensate. 1.

We consider a nonlinear evolution equation recently proposed to describe the small-

Wilson renormalization group for low {bold {ital x}} physics: Towards the high density regime

x

The BFKL equation from the Wilson renormalization group

hadronic physics in the regime of very high gluon density. This is a functional Fokker-Planck equation in terms of a classical random color source, which represents the color charge density of the partons with large

The renormalization group equation for the color glass condensate

x

The quark?gluon medium

. In the saturation regime of interest, the coefficients of this equation must be known to all orders in the source strength. In this first paper of a series of two, we carefully derive the evolution equation, via a matching between classical and quantum correlations, and set up the framework for the exact background source calculation of its coefficients. We address and clarify many of the subtleties and ambiguities which have plagued past attempts at an explicit construction of this equation. We also introduce the physical interpretation of the saturation regime at small

Cherenkov glue in opaque nuclear medium

x

On Collective Properties of Dense QCD Matter

as a Color Glass Condensate. In the second paper we shall evaluate the expressions derived here, and compare them to known results in various limits.

Quantum spectrum of Cherenkov glue

We continue the study of the effective action for low {ital x} physics based on a Wilson renormalization group approach. We express the full nonlinear renormalization group equation in terms of the average value and the average fluctuation of extra color charge density generated by integrating out gluons with intermediate values of x. This form clearly exhibits the nature of the phenomena driving the evolution and should serve as the basis of the analysis of saturation effects at high gluon density at small x. {copyright} {ital 1998} {ital The American Physical Society}

On the kinetic theory of energy losses in a randomly heterogeneous medium

Abstract We discuss the Wilson renormalization group approach to the effective action for low x physics. It is shown that in the linearized, weak field regime the RG equation reduces to the BFKL equation for the evolution of the unintegrated gluon density. We discuss the relation of this approach with that of Lipatov.

Measuring Hadronization Length in e^+ e^- \rightarrow K^0 {\bar{K}}^0 \gamma

Abstract We present an explicit and simple form of the renormalization group equation which governs the quantum evolution of the effective theory for the Color Glass Condensate (CGC). This is a functional Fokker–Planck equation for the probability density of the color field which describes the CGC in the covariant gauge. It is equivalent to the Euclidean time evolution equation for a second quantized current–current Hamiltonian in two spatial dimensions. The quantum corrections are included in the leading log approximation, but the equation is fully non-linear with respect to the generally strong background field. In the weak field limit, it reduces to the BFKL equation, while in the general non-linear case it generates the evolution equations for Wilson-line operators previously derived by Balitsky and Kovchegov within perturbative QCD.