Matrix element corrections in the Pythia8 parton shower in the context of matched simulations at next-to-leading order

Autor:	Frixione, Stefano, Amoroso, Simone, Mrenna, Stephen
Rok vydání:	2023
Předmět:	High Energy Physics - Phenomenology
Druh dokumentu:	Working Paper
Popis:	We discuss the role of matrix element corrections (MEC) to parton showers in the context of MC@NLO-type matchings for processes that feature unstable resonances, where MEC are liable to result in double-counting issues, and are thus generally not employed. By working with Pythia8, we show that disabling all MEC is actually unnecessary in computations based on the narrow-width approximation, and we propose alternative MEC settings which, while still avoiding double counting, allow one to include hard-recoil effects in the simulations of resonance decays. We illustrate our findings by considering top-antitop production at the LHC, and by comparing MadGraph_aMC@NLO predictions with those of POWHEG-BOX and standalone Pythia8. Comment: 16 pages, 9 figures
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/2308.06389 Zobrazit plný text záznamu View this record from Arxiv