GQLink: an implementation of Quantized State Systems (QSS) methods in Geant4

Journal Article · 17 October 2018 · Journal of Physics. Conference Series

DOI: https://doi.org/10.1088/1742-6596/1085/5/052015 · OSTI ID:1525459

Santi, Lucio ^[1]; Bergero, Federico ^[2]; Jun, Soon Yung  ^[3]; Genser, Krzysztof  ^[3]; Elvira, Daniel  ^[3]; Castro, Rodrigo ^[1]

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1. Univ. of Buenos Aires (Argentina); ICC-CONICET (Argentina)
2. CIFASIS-CONICET (Argentina)
3. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

Simulations in high energy physics (HEP) often require the numerical solution of ordinary differential equations (ODE) to determine the trajectories of charged particles in a magnetic field when particles move throughout detector volumes. Each crossing of a volume interrupts the underlying numerical method that solves the equations of motion, triggering iterative algorithms to estimate the intersection point within a given accuracy. The computational cost of this procedure can grow significantly depending on the application at hand. Quantized State System (QSS) is a recent family of discrete-event driven numerical methods exhibiting attractive features for this type of problems, such as native dense output (sequences of polynomial segments updated only by accuracy-driven events) and lightweight detection and handling of volume crossings. In this work we present GQLink, a proof-of-concept integration of QSS with the Geant4 simulation toolkit which stands as an interface for co-simulation that orchestrates robustly and transparently the interaction between the QSS simulation engine and aspects such as geometry definition and physics processes controlled by Geant4. In conclusion, we validate the accuracy and study the performance of the method in simple geometries (subject to intense volume crossing activity) and then in a realistic HEP application using a full CMS detector configuration.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
• Grant/Contract Number: AC02-07CH11359
• OSTI ID: 1525459
• Report Number(s): FERMILAB-CONF-17-698-CD; 1700014
• Journal Information: Journal of Physics. Conference Series, Journal Name: Journal of Physics. Conference Series Journal Issue: 5 Vol. 1085; ISSN 1742-6588
• Publisher: IOP PublishingCopyright Statement
• Country of Publication: United States
• Language: English