Pavel Demin
Research scientist. Funding: UCL.

Centre for Cosmology, Particle Physics and Phenomenology - CP3
Université catholique de Louvain
2, Chemin du Cyclotron - Box L7.01.05
B-1348 Louvain-la-Neuve
+32 10 47 3165
UCL member card
I am involved in the following research directions:

a C++ software package to compute Matrix Element weights: MoMEMta

MoMEMta is a C++ software package to compute Matrix Element weights. Designed in a modular way, it covers the needs of experimental analysis workflows at the LHC. MoMEMta provides working examples for the most common final states (Formula: 0, WW, ...). If you are an expert user, be prepared to feel the freedom of configuring your MEM computation at all levels.
MoMEMta is based on:

- C++, ROOT, Lua scripting language
- Cuba (Monte-Carlo integration library)
- External PDFs (LHAPDF by default)
- External Matrix Elements (currently provided by our MadGraph C++ exporter plugin)

Development of a framework for fast simulation of a generic collider experiment: Delphes

Observability of new phenomenological models in High Energy experiments is delicate to evaluate, due to the complexity of the related detectors, DAQ chain and software. Delphes is a new framework for fast simulation of a general purpose experiment. The simulation includes a tracking system, a magnetic field, calorimetry and a muon system, and possible very forward detectors arranged along the beamline. The framework is interfaced to standard file format from event generators and outputs observable analysis data objects. The simulation takes into account the detector resolutions, usual reconstruction algorithms for complex objects (FastJet) and a simplified trigger emulation. Detection of very forward scattered particles relies on the transport in beamlines with the Hector software.

NA62 computing

NA62 will look for rare kaon decays at SPS accelerator at CERN. A total of about $10^{12}$ kaon decays will be produced in two/three years of data taking. Even though the topology of the events is relatively simple, and the amount of information per event small, the volume of data to be stored per year will be of the order of ~1000 TB. Also, an amount of 500 TB/year is expected from simulation.

Profiting from the synergy inside CP3 in sharing computer resources our group is participating in the definition of the NA62 computing scheme. CP3 will be also one of the grid virtual organization of the experiment.

External collaborators: INFN (Rome I), University of Birmingham, University of Glasgow.

The CMS silicon strip tracker upgrade

Development of the "phase II" upgrade for the CMS silicon strip stracker.

More precisely, we are involved in the development of the uTCA-based DAQ system and in the test/validation of the first prototype modules. We take active part to the various test-beam campaigns (CERN, DESY, ...)

This activity will potentially make use of the cyclotron of UCL, the probe stations and the SYCOC setup (SYstem de mesure de COllection de Charge) to test the response to laser light, radioactive sources and beams.

The final goal is to take a leading role in the construction of part of the CMS Phase-II tracker.

External collaborators: CRC and CMS collaboration.

Tomography of large structures using cosmic-ray muons

The general goal of this project is to develop muon-based tomography (“muography”), an innovative multidisciplinary approach to study geological structures, establishing a strong synergy between geophysics and particle physics.
Muography is an imaging technique that relies on the measurement of the absorption of muons produced by the interactions of cosmic rays with the atmosphere.
Applications span from geophysics (the study of the interior of mountains and the remote quasi-online monitoring of active volcanoes) to archaeology and mining.

We are part of international networks (G-ENDEAVOR, European Muography Network) that bring together particle physicists and geophysicists for the development and exploitation of high-resolution portable detectors.

We are using the local facilities at CP3 (e.g., the gRPC cosmic test bench) for further hardware developments.
We also participate to the MURAVES collaboration, now merged into the MIVAS collaboration, through algorithmic and data-analysis aspects like the implementation of time-of-flight capabilities, the analysis of control data for the optimization of the reconstruction algorithms, and the understanding of physics and instrumental backgrounds by data-driven and simulation techniques.

External collaborators: G-ENDEAVOR and European Muography Network (Japan, Italy, France, UK, Hungary); MIVAS Collaboration (France and Italy) including CNRS (France), INFN (Italy), INGV(Italy).

World LHC Computing Grid: the Belgian Tier2 project

The World LHC Computing GRID (WLCG) is the worldwide distributed computing infrastructure controlled by software middleware that allows a seamless usage of shared storage and computing resources.

About 10 PBytes of data are produced every year by the experiments running at the LHC collider. This data must be processed (iterative and refined calibration and analysis) by a large scientific community that is widely distributed geographically.

Instead of concentrating all necessary computing resources in a single location, the LHC experiments have decided to set-up a network of computing centres distributed all over the world.

The overall WLCG computing resources needed by the CMS experiment alone in 2016 amount to about 1500 kHepSpec06 of computing power, 90 PB of disk storage and 150 PB of tape storage. Working in the context of the WLCG translates into seamless access to shared computing and storage resources. End users do not need to know where their applications run. The choice is made by the underlying WLCG software on the basis of availability of resources, demands of the user application (CPU, input and output data,..) and privileges owned by the user.

Back in 2005 UCL proposed the WLCG Belgian Tier2 project that would involve the 6 Belgian Universities involved in CMS. The Tier2 project consists of contributing to the WLCG by building two computing centres, one at UCL and one at the IIHE (ULB/VUB).

The UCL site of the WLCG Belgian Tier2 is deployed in a dedicated room close to the cyclotron control room of the IRMP Institute and is currently a fully functional component of the WLCG.

The UCL Belgian Tier2 project also aims to integrate, bring on the GRID, and share resources with other scientific computing projects. The projects currently integrated in the UCL computing cluster are the following: MadGraph/MadEvent, NA62 and Cosmology.

External collaborators: CISM (UCL), Pascal Vanlaer (Belgium, ULB), Lyon computing centre, CERN computing centre.

Past projects
Hide past projects.

I am involved in the following research directions:

Advanced Techniques for Fast Simulation and Data Analysis in High Energy Physics (ASAP)

The discovery of the 125GeV Higgs boson by the LHC experiments has finally opened a new era in the exploration of the TeV scale. The physics programs of CMS and ATLAS aim far beyond the simple discovery, and vigorously pursue the full characterization of the newly discovered state and the full exploration of the TeV scale in search of new phenomena. A key lesson drawn from first two years of LHC running is that most probably first discoveries and then identification of new states/interactions will not be easy. On the one hand, model-independent searches in simple topologies such as single/multi lepton at high transverse momenta have not shown any hint of new physics so far. On the other, topologies with jets and/or missing transverse energies, much more challenging experimentally, do strongly depend on the underlying theoretical models so that efficiently identifying signal enhanced regions of the phase space is quite involved. In this context, multi-variate techniques have become more and more central in the analysis of data from hadron collider experiments, to maximally exploit the information available on the signal and on the backgrounds. Amongst the most advanced techniques and certainly the most powerful one from the theoretical point of view, the so called matrix element method stands out. The main goal of this proposal is to advance the use and the scope of the matrix-element method so to significantly extend the range of physics applications at the LHC to the search of new physics. First we aim at providing the experimental HEP community with complete and automatic simulation tools, such as MadWeight/MoMEMta and Delphes, that overcome the technical limitations of the method. Second we propose to test and apply the new tools to current analyses in signatures that involve final state leptons and b-jets. Finally, we explore new and original applications of the method to both model-dependent or model-independent searches of new physics at the LHC.

External collaborators: CMS collaboration.

Publications in CP3
All my publications on Inspire


DELPHES 3, A modular framework for fast simulation of a generic collider experiment
de Favereau, J. and others
[Abstract] [PDF] [Journal] Published in JHEP
Refereed paper. 25th July.


CMS Tracking Performance Results from early LHC Operation
CMS collaboration
[Abstract] [PDF] [Journal] [Full text] Published in Eur.Phys.J.C70:1165-1192,2010.
Refereed paper. 21st December.


Alignment of the CMS Silicon Tracker during Commissioning with Cosmic Rays
CMS Collaboration
[Abstract] [PDF] [Journal] [Full text] CMS PAPER CFT-09-003
Published in JINST

Refereed paper. 26th December.
Commissioning and Performance of the CMS Pixel Tracker with Cosmic Ray Muons
CMS Collaboration
[Abstract] [PDF] [Journal] [Full text] CMS-CFT-09-001.
Published in JINST

Refereed paper. 26th December.
CMS Data Processing Workflows during an Extended Cosmic Ray Run
CMS Collaboration
[Abstract] [PDF] [Journal] [Full text] Published in JINST
Refereed paper. 21st December.


The CMS experiment at the CERN LHC
The CMS Collaboration
[Journal] [Full text] The CMS Collaboration, "The CMS experiment at the CERN LHC", 2008 JINST 3 S08004, 361pp doi: 10.1088/1748-0221/3/08/S08004.
Refereed paper. 10th December.


Tagging b jets with electrons and muons at CMS
P. Demin, S. de Visscher, A. Bocci, R. Ranieri
[Full text] CERN-CMS-NOTE-2006-043
Public experimental note. 31st December.

[UCLouvain] - [SST] [IRMP] - [SC]
Contact : Jérôme de Favereau
Job opportunities Postdoctoral position: Search for Hidden Sector mediations at NA62 experiment
EOS be.h : 10 PhD positions
Postdoctoral position: Data Analysis and GTK operation for NA62 experiment
Postodoctoral position in precision and BSM Phenomenology
Postdoctoral Position in Precision Computations for the LHC