Parallel Monte-Carlo event generation for HPC

We develop programs that allow for a convenient use of HPC resources for the task of Monte-Carlo event-generation. Data parallelism is based on HDF5 while computational parallelism is using ASCR’s DIY.
For the time being we have two prototypes that can be used in physics applications that require significant CPU resources.

One of them uses Pythia8 for all simulation purposes while the other has an additional step, namely reading in matrix-level events in the common “Les Houches Event” (LHE) format — albeit converted for scalability to HDF5. In the latter application, Pythia8 is then used for the particle level event simulation step as well as multijet-merging.

Both applications are hooked up with Rivet in order to analyse the simulated collision events and write out histograms suitable for immediate comparison with the experimentally measured counterparts.

A pictorial representation of the program flow can be found below.


Schematic program flow of our parallel event generation program.

CPU-cost analysis of event-generation for matrix element (ME) and particle level simulation. This example is a simulation of W+ up to 8 jets.