Numerical solution of the nonlinear evolution equation at small x with impact parameter and beyond the leading logarithmic approximation

The nonlinear evolution equation at small x with impact parameter dependence is analyzed numerically. The saturation scales and the radius of expansion in the impact parameter are extracted as functions of rapidity. Running coupling is included in this evolution, and it is found that the solution is sensitive to the infrared regularization. Kinematical effects beyond the leading logarithmic approximation are taken partially into account by modifying the kernel which includes the rapidity-dependent cuts. These effects are important for the nonlinear evolution with the impact parameter dependence.