Multiplicative NLO matching in DIS with Pythia 8

6 May 2026, 11:15
20m
Sala GIOVE A, Ground Floor (Hotel Carlton)

Sala GIOVE A, Ground Floor

Hotel Carlton

Talk WG4 QCD with Heavy Flavors and Hadronic Final States WG4 QCD with Heavy flavours and Hadronic Final States

Speakers

Ilkka Helenius (University of Jyväskylä) Joni Laulainen (University of Jyväskylä)

Description

We present a multiplicative matching scheme for neutral-current deep inelastic scattering implemented in the latest version of the Pythia 8 event generator. The method reweigths leading-order events to achieve next-to-leading-order (NLO) accuracy for inclusive observables. We compute NLO weights fully differential in Born variables and use matrix-element corrections to produce correct real-emission probabilities in the parton shower. The massless NLO structure functions are implemented with full interference between a photon and a Z boson with an option to consider each component separately. This is the first process that can be generated at NLO accuracy internally in Pythia without resorting to external tools for matrix-element generation. We validate the method against similar implementations in Sherpa and Powheg event generators, compare to cross sections measured at the HERA collider and discuss implications to the future Electron-Ion Collider.

Speaker confirmation No

Authors

Dr Christian Preuss (University of Göttingen) Ilkka Helenius (University of Jyväskylä) Joni Laulainen (University of Jyväskylä)

Presentation materials