Transverse momentum distributions in Semi-inclusive Deep Inelastic Scattering

Within a perturbative approach to Quantum Chromodynamics (QCD), we show how to extend ordinary DGLAP longitudinal evolution equations to include the radiative transverse momentum generated in the collinear branching regime. Considering Semi-inclusive Deep Inelastic Scattering as a reference process, we perform such a generalization both in the current and in the target fragmentation region. These distributions are then used to predict semi-inclusive Deep Inelastic Scattering cross-sections onto the whole phase space of the detected hadron.Comment: 6 pages. Invited talk at "Symmetries and Spin", Prague, July 19-2

Construction of nice nilpotent Lie groups

We illustrate an algorithm to classify nice nilpotent Lie algebras of dimension $n$ up to a suitable notion of equivalence; applying the algorithm, we obtain complete listings for $n\leq9$. On every nilpotent Lie algebra of dimension $\leq 7$, we determine the number of inequivalent nice bases, which can be $0$, $1$, or $2$. We show that any nilpotent Lie algebra of dimension $n$ has at most countably many inequivalent nice bases.Comment: v3: Condition (N3) has been changed to exclude diagrams with arrows with the same label as the starting node, this will not affect the rest of the paper or the results, since this condition was implicitly assumed through the paper. Added a final remark 3.9. Presentation improved and bibliography updated. Article 28 Pages; Tables in ancillary file 137 page