Speaker
Description
We discuss Transverse Momentum Dependent (TMD) gluon distributions within high energy factorization at next-to-leading order in the strong coupling within the framework of Lipatov's high energy effective action. Unlike previous results obtained within high energy factorization, our framework allows to recover the complete anomalous dimension associated with Collins-Soper-Sterman (CSS) evolution of the TMD distribution, including also single-logarithmic terms in the CSS evolution. Another interesting feature concerns the relation between unpolarized and linearly polarized gluon TMD in the BFKL limit. While our calculation confirms that both distributions agree in the BFKL limit at leading order, we find that they differ, once next-to-leading order corrections are being included. We furthermore establish a link between the QCD operator definition of the TMD gluon distribution and a previously derived off-shell TMD gluon-to-gluon splitting function, which is within the present framework obtained as the real 1-loop correction.
