8–12 Sept 2025
Hamburg, Germany
Europe/Berlin timezone

Autoregressive Models for the Fast Calorimeter Simulation of the ATLAS Calorimeter

11 Sept 2025, 16:40
20m
ESA M

ESA M

Oral Track 1: Computing Technology for Physics Research Track 1: Computing Technology for Physics Research

Speaker

Florian Ernst (Heidelberg University (DE))

Description

For high-energy physics experiments, the generation of Monte Carlo events, and particularly the simulation of the detector response, is a very computationally intensive process. In many cases, the primary bottleneck in detector simulation is the detailed simulation of the electromagnetic and hadronic showers in the calorimeter system.

ATLAS is currently using its state-of-the-art fast simulation tool AtlFast3, which employs a combination of histogram-based parameterizations and Generative Adversarial Networks (GANs) to provide a highly efficient yet accurate simulation of the full detector response.

Motivated by the Fast Calorimeter Simulation Challenge, which concluded with a community paper demonstrating the superiority of modern generative models — such as diffusion models, transformers and (continuous) normalizing flows — over more traditional approaches like GANs and variational autoencoders, the applicability of these next-generation techniques to the ATLAS fast calorimeter simulation was explored.
In this talk, first physics performance results of these novel models are presented. The models are trained on a newly generated input dataset with extended pseudorapidity coverage and optimized granularity that allows to reproduce the detailed simulation with a reduced number of voxels.

Significance

This presentation will provide first performance results of new generative models for fast calorimeter simulation that are expected to replace the currently used GAN-based simulation in ATLAS's state-of-the-art fast simulation toolkit AtlFast3

Experiment context, if any ATLAS Experiment

Authors

Federico Andrea Corchia (Universita e INFN, Bologna (IT)) Florian Ernst (Heidelberg University (DE)) Joshua Falco Beirer (CERN) Peter McKeown (CERN) Rui Zhang (Nanjing University (CN))

Presentation materials