Dipole cross-section

This is a library of routines in order to compute the Fourier transform C(k) of the correlator (U(0)U^+(x)) that appears frequently in the Colored Glass Condensate model for high energy hadronic interactions (U(x) is a unitary matrix in the fundamental representation of SU(Nc) that appears in the eikonal interaction of a quark at the transverse position x). The average is evaluated here in the McLerran-Venugopalan model, but the code that performs the Fourier transform can be reused for any other model.
The main difficulty of this computation is to calculate accurately integrals of oscillating functions. This is done by rewritting the integrals as alternated sign series, which are then summed using Euler's convergence acceleration method.
The compressed tar archive containing the library is available at libCk.tar.gz. Although the core of the library is written in C, there is a wrapper library in order to make its routines callable from a program written in FORTRAN. Example programs using this library are provided both for C and FORTRAN.