Event Generation at the HL-LHC with Sherpa and Pepper

by Enrico Bothmann (CERN)

Thursday 26 Mar 2026, 14:00 → 15:00 Europe/Zurich

Aula Caldirola (University of Milan Statale)

The High-Luminosity LHC (HL-LHC) era presents unprecedented challenges for Monte Carlo event generators, demanding both higher theoretical accuracy and significantly increased computational throughput. In this talk I present recent developments in the Sherpa event generator framework and the portable parton-level event generator Pepper, addressing both of these fronts.

In the first part, I discuss advances in physics accuracy and capabilities in Sherpa, including a new method to calculate polarised cross sections for electroweak studies, progress toward a fully next-to-leading-logarithmic accurate parton shower, new results for photon-induced processes, and a new tool for systematic hadronisation uncertainty studies, among others.

In the second part, I turn to the computational challenges of the HL-LHC physics programme and present our strategy for fast event generation on high-performance computing clusters and heterogeneous architectures. I describe efforts to adapt amplitude evaluation for modern GPU hardware, and present benchmarks for performance, energy efficiency, and numerical accuracy. I further discuss integration with machine-learning methods, and offer a preliminary look at the prospects for porting one-loop amplitudes to highly parallel computing architectures.

slides_bothmann.pdf