arXiv subjects
Publications and source records attributed to Christopher Wever.
This is a contribution to the proceedings of the 2016 "Loops and legs" conference, based on the talk by HF. The talk was based on the paper "On the reduction of Generalized Polylogarithms to $\text{Li}_n$ and $\text{Li}_{2,2}$ and on the reduction thereof" by the three authors, published in March 2016 in JHEP.
We give expressions for all generalized polylogarithms up to weight four in terms of the functions log, $\text{Li}_n$, and $\text{Li}_{2,2}$, valid for arbitrary complex variables. Furthermore we provide algorithms for manipulation and numerical evaluation of $\text{Li}_n$ and $\text{Li}_{2,2}$, and add codes in Mathematica and C++ implementing the results. With these results we calculate a number of previously unknown integrals, which we add in App. C.
We present the calculation of massless two-loop Master Integrals relevant to five-point amplitudes with one off-shell external leg and derive the complete set of planar Master Integrals with five on-mass-shell legs, that contribute to many $2\to 3$ amplitudes of interest at the LHC, as for instance three jet production, $γ, V, H +2$ jets etc., based on the Simplified Differential Equations approach.
We calculate the complete set of two-loop Master Integrals with two off mass-shell legs with massless internal propagators, that contribute to amplitudes of diboson $V_1V_2$ production at the LHC. This is done with the Simplified Differential Equations approach to Master Integrals, which was recently proposed by one of the authors.
A short review is given of the simplified differential equations approach to Master Integrals, which was recently proposed by one of the authors. We show its applicability by calculating some non-trivial two-loop planar Master Integrals, namely those contributing to amplitudes of massive diboson VV' production at the LHC with massless internal lines.
We present predictions for the total cross sections for pair production of squarks and gluinos at the LHC including a combined NNLL resummation of soft and Coulomb gluon effects. The NNLL corrections can be up to 25% relative to previous NLL results and reduce the theoretical uncertainties to the 10% level.
We study the implication of finite squark and gluino decay widths for threshold resummation of squark and gluino production cross sections at the LHC. We find that for a moderate decay width (Gamma/m < 5%) higher-order soft and Coulomb corrections are appropriately described by NLL calculations in the zero-width limit including the contribution from bound-state resonances below threshold, with the remaining uncertainties due to finite-width effects of a similar order as the ambiguities of threshold-resummed higher-order calculations.