Physics

Petabyte

Aerospace engineering

Mathematics

Structural engineering

Biology

Large Hadron Collider

Particle physics

Operating system

Algorithm

Statistics

Ranging

Engineering

Paleontology

Parameterized complexity

Atlas (anatomy)

Monte Carlo method

Range (aeronautics)

ATLAS experiment

Computer science

Big data

Substructure

Simulation

Computational science

Telecommunications

Detector

Computing and Software for Big Science

The ATLAS experiment at the Large Hadron Collider has a broad physics programme ranging from precision measurements to direct searches for new particles and new interactions, requiring ever larger and ever more accurate datasets of simulated Monte Carlo events. Detector simulation with Geant4 is accurate but requires significant CPU resources. Over the past decade, ATLAS has developed and utilized tools that replace the most CPU-intensive component of the simulation—the calorimeter shower simulation—with faster simulation methods. Here, AtlFast3, the next generation of high-accuracy fast simulation in ATLAS, is introduced. AtlFast3 combines parameterized approaches with machine-learning techniques and is deployed to meet current and future computing challenges, and simulation needs of the ATLAS experiment. With highly accurate performance and significantly improved modelling of substructure within jets, AtlFast3 can simulate large numbers of events for a wide range of physics processes.

AtlFast3: The Next Generation of Fast Simulation in ATLAS