9-13 July 2018
Sofia, Bulgaria
Europe/Sofia timezone

Deployment of a Matrix Element Method code for the ttH channel analysis on GPU's platform

12 Jul 2018, 12:15
15m
Hall 9 (National Palace of Culture)

Hall 9

National Palace of Culture

presentation Track 6 – Machine learning and physics analysis T6 - Machine learning and physics analysis

Speaker

Gilles Grasseau (Centre National de la Recherche Scientifique (FR))

Description

In the proton-proton collisions at the LHC, the associate production of the Higgs boson with two top quarks has not been observed yet. This ttH channel allows directly probing the coupling of the Higgs boson to the top quark. The observation of this process could be a highlight of the ongoing Run 2 data taking.

Unlike to supervised methods (neural networks, decision trees, support vector machines, …), the Matrix Element Method (MEM) allows to classify events by computing the probability that a final state occurs thanks to the physic laws involved. This sophisticated method is however very CPU time consuming to explore all possible final states and requires huge powerful computing platform to perform the CMS analyses carried out at our laboratory in a reasonable time.

The Matrix Element method is based on the computation of high dimensional integrals. We will describe how we develop and deploy our MEM production code on GPU's platform. Especially, how we adapted the main components of these computations into OpenCL kernels: VEGAS, the MadGraph code generator to compute the Matrix Element terms and the parton distribution function calculations for LHAPDF part.

We will conclude by discussing about the gain obtained on GPU's platforms (> 20 GPUs) compared with classical CPU's platforms.

Primary author

Gilles Grasseau (Centre National de la Recherche Scientifique (FR))

Co-authors

Florian Beaudette (Centre National de la Recherche Scientifique (FR)) Alexandre Zabi (Centre National de la Recherche Scientifique (FR)) Cristina Martin Perez (Centre National de la Recherche Scientifique (FR)) Mr Arnaud Chiron (Centre National de la Recherche Scientifique (FR)) Thomas Strebler (Imperial College (GB)) Gabriel Hautreux (GENCI - FR)

Presentation materials