Future prospects for parton showers

Abstract

In this brief Snowmass White Paper for the Theory Frontier, we argue that there have been important recent developments in the algorithms used to generate a simulated parton shower and that further progress can be achieved in the coming decade. A much more detailed exposition can be found in a corresponding White Paper of the Energy Frontier. * Herwig, however rearranges the ordering of splittings in its default parton shower so that larger angle splittings come first.

Electroweak radiative corrections in precision LHC measurements of W±/Z0+jets

“…In this case, our NLO predictions are generated with or without the inclusion of real and virtual EW corrections, allowing us to investigate different settings in the evaluation of EW-sensitive events in Herwig 7. The predicted signals are compared with the experimental measurements from the ATLAS collaboration [27,28] and against third-party theoretical predictions within the k t -factorisation framework [29][30][31], using the unintegrated parton distribution functions (UPDFs) of Kimber-Martin-Ryskin (KMR) [32,33]. The latter framework has been used as a control signal since its validity in accurately predicting the behaviour of experimental observations has been repeatedly proven to be independent of the use parton shower enhancements [34][35][36][37][38][39], while being computationally expensive and unsuitable for use in general-purpose event generators [45][46][47][48]. Note that the production of W ± and Z 0 bosons in association with hadronic jets have been studied extensively in the literature, e.g.…”