Towards transverse-momentum-dependent splitting functions in kT-factorization
2019 July 08
We present a calculation of transverse momentum dependent real emission contributions to splitting functions within kT-factorization [EPJC 78 (2018), 174; JHEP 01 (2016) 181; PRD 94 (2016), 114013], giving special attention to the gluon-to-gluon splitting. The calculation is performed in a formalism that generalizes the framework of [NPB 175 (1980) 27; NPB 427 (1994) 475]. The advantage of the presented approach is that the obtain splitting functions fulfill appropriate limits. In particular, the gluon-to-gluon splitting function reduces to the leading order BFKL kernel in the low $z$ limit, to the DGLAP gluon-to-gluon splitting function in the collinear limit as well as to the CCFM kernel in the angular ordered region. In the last part of the contribution we comment also on the calculation of virtual corrections to the obtain splitting functions.