Particle physics experiments make heavy use of the Geant4 simulation package to model interactions between subatomic particles and bulk matter. Geant4 itself employs a set of carefully validated physics models that span a wide range of interaction energies.
They rely on measured cross-sections and phenomenological models with the physically motivated parameters that are tuned to cover many application domains.
The aggregated sum of these components is what experiments use to study their apparatus.
This raises a critical question of what uncertainties are associated with a particular tune of one or another Geant4 physics model, or a group of models, involved in modeling and optimization of a detector design.
In response to multiple requests from the simulation community, the Geant4 Collaboration has started an effort to address the challenge.
We have designed and implemented a comprehensive, modular, user-friendly software toolkit that allows modifications of parameters of one or several Geant4 physics models involved in the simulation studies, and to perform collective analysis of multiple variants of the resulting physics observables of interest, in order to estimate an uncertainty on a measurement due to the simulation model choices.
Based on modern event-processing infrastructure software, the toolkit offers a variety of attractive features, e.g. flexible run-time configurable workflow, comprehensive bookkeeping, easy to expand collection of analytical components.
Design, implementation technology , and key functionalities of the toolkit will be presented and highlighted with selected results.
Keywords: Geant4 model parameters perturbation, systematic uncertainty in detector simulation
|Primary Keyword (Mandatory)||Simulation|