Contact
Name
Fabio Maltoni

Position
Professor

Email
fabio.maltoni@uclouvain.be

Address
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
Belgium

Phone
+32 10 47 3166

Office
E.247

Personal homepage
http://maltoni.home.cern.ch

UCL member card
http://www.uclouvain.be/fabio.maltoni
Teaching at UCL
Quantum Mechanics
PHY1222
First course on Quantum Mechanics.
45h+30h, 5 ECTS

Relativistic Quantum Mechanics
PHY2125
Introduction to the Dirac Equation.
15h+15h, 4 ECTS

Electroweak interactions
PHY2224
Introduction to the Standard Model of the electroweak interactions.
22.5h, 4 ECTS (shared with J.M.Gerard)

Strong interactions and symmetries
PHY2223
Introduction to perturbative QCD and symmetries
30h, 5 ECTS (shared with J.M.Gerard)

Seminars of theoretical and mathematical physics
PHY2501
Invited lectures on special topics.
15h, 2 ECTS.
People responsibilities
Research scientists
Olivier Mattelaer (UCL-cadre - UCL) (member since September 2005)
Responsible software maintenance and development of MadGraph 5, AMC@NLO (including MadSpin and ALOHA). Study of new experimental approaches using the matrix element re-weighting.

Postdocs
Jan Heisig (FNRS)
Michele Lucente (IISN - H2020-MSCA-IF-2016) (member since January 2016)
I work on extensions of the Standard Model of particle physics aimed at accounting for the observed neutrino masses and flavour mixing, the origin of the baryon asymmetry of the Universe and the nature of dark matter. I am currently developing a new computer tool (MadbaM) devoted to precision computations of the baryon asymmetry of the Universe in beyond the Standard Model realisations.
Manoj Kumar Mandal (member since October 2016)
Ken Mimasu (UCL-cadre - PAI, MSCA) (member since October 2016)
Collider phenomenology beyond the Standard Model, particularly on extended scalar sectors (two-Higgs doublet models, axion-like particles). Probing the Electroweak phase transition at the LHC. Confronting Baryogenesis via a strong electroweak phase transition with collider signatures at the LHC and beyond. Precision Higgs measurements and global fits in the framework of effective field theory.
Ambresh Shivaji (Move-In Louvain) (member since September 2016)
I work in the area of collider physics. My current research interests include phenomenology of loop-induced processes in the SM and beyond, higher order quantum corrections and model independent approach to the study of new physics effects (mainly in the Higgs sector) at colliders.

Visitors
Roberto Franceschini (member since October 2017)
Probing fundamental interactions ...
Antonio Santos
BSM physics and dark matter.

PhD students
Luca Mantani (UCL-cadre - MCnetITN3) (member since September 2016)
I work on LHC phenomenology, in particular how to detect new interactions among SM and interpret them via the SMEFT.
Stefan von Buddenbrock (member since February 2019)
Xiaoran Zhao (UCL-cadre - MCnetITN3) (member since April 2017)
Higgs phenomonology.

Master students

Former members
Research statement
The high energy and luminosity of the present and future colliders, from the Tevatron (FNAL) to the Large Hadron Collider (CERN) to a Tev Linear Collider, will offer the widest range of physics opportunities to the exploration of the high-energy frontier. Among the highest priorities is understanding not only the nature of the electroweak symmetry breaking (EWSB) but also the mechanism through which the electroweak scale stabilizes. Simple and very robust arguments indicate that this scale should be less than one TeV, very much in the reach of the above mentioned colliders. At this energy, spectacular events take place and mulijet final states in association with leptons or missing energy constitutes the most interesting data samples. The quest for the Higgs boson(s) and/or for supersymmetric particles will rely on our ability of predicting both the signal and the standard model processes which are the backgrounds of these searches.

The difficulty of detecting such signatures asks for a dedicated and joint effort of all the high-energy physics community. Not only the best theoretical predictions for the expected signals will be necessary, but also a very good understanding of the large QCD backgrounds and the detectors responses will allow us to unreveal the mechanism of EWSB. In this respect, I consider of primary importance for theorists to work in close contact with experimentalists.

In the next crucial years which will see the first new data from the LHC, I plan to focus my efforts in two main directions:

  1. provide new and/or more precise evaluations of the most important signatures that probe the the EWSB mechanism, such as top and Higgs boson(s) production both in the standard model and its extensions.
  2. provide the experimentalists at the colliders with the means to simulate events occurring at the energy frontier.
Projects
Research directions:
Phenomenology of elementary particles
Data analysis in HEP experiments

Experiments and collaborations:
CMS

Active projects
Advanced Multi-Variate Analysis for New Physics Searches at the LHC
Christophe Delaere, Andrea Giammanco, Vincent Lemaitre, Fabio Maltoni, Alessia Saggio

With the 2012 discovery of the Higgs boson at the Large Hadron Collider, LHC, the Standard Model of particle physics has been completed, emerging as a most successful description of matter at the smallest distance scales. But as is always the case, the observation of this particle has also heralded the dawn of a new era in the field: particle physics is now turning to the mysteries posed by the presence of dark matter in the universe, as well as the very existence of the Higgs. The upcoming run of the LHC at 13 TeV will probe possible answers to both issues, providing detailed measurements of the properties of the Higgs and extending significantly the sensitivity to new phenomena.

Since the LHC is the only accelerator currently exploring the energy frontier, it is imperative that the analyses of the collected data use the most powerful possible techniques. In recent years several analyses have utilized multi-variate analysis techniques, obtaining higher sensitivity; yet there is ample room for further improvement. With our program we will import and specialize the most powerful advanced statistical learning techniques to data analyses at the LHC, with the objective of maximizing the chance of new physics discoveries.

We are part of a network of European institutions whose goal is to foster the development and exploitation of Advanced Multi-Variate Analysis (AMVA) for New Physics searches. The network offers extensive training in both physics and advanced analysis techniques to graduate students, focusing on providing them with the know-how and the experience to boost their career prospects in and outside academia. The network develops ties with non-academic partners for the creation of interdisciplinary software tools, allowing a successful knowledge transfer in both directions. The network studies innovative techniques and identifies their suitability to problems encountered in searches for new physics at the LHC and detailed studies of the Higgs boson sector.

External collaborators: University of Oxford, INFN, University of Padova, Université Blaise Pascal, LIP, IASA, CERN, UCI, EPFL, B12 Consulting, SDG Consulting, Yandex, MathWorks.
Complementarity of dark matter searches in simplified models
Chiara Arina, Fabio Maltoni

Study of the complementarity between dark matter relic abundance, direct detection, indirect detection and collider searches applied to the dark matter simplified models. These models consider a dark matter candidate communicating to the quark (especially top) sector of the standard model via a bosonic or vectorial mediator.

External collaborators: Eric Conte (GPRHE), Benjamin Fuks (LPTHE), Jun Guo (Chinese Academy of Science), Jan Heisig (RWTH), Kentarou Mawatari (LPSC Grenoble), Michael Kraemer (RWTH), Mathieu Pellen (University of Wuerzburg).
EFT@NLO
Céline Degrande, Fabio Maltoni

Implementation of the SMEFT at NLO in QCD in the Feynrules MadGraph5_aMC@NLO chain and phenomenological studies

External collaborators: Cen Zhang, Celine Degrande.
Electroweak corrections
Fabio Maltoni

Automation of the calculation of NLO Electroweak corrections and phenomenological studies of their impact on Standard-Model and Beyond-the-Standard-Model processes at colliders.
FeynRules
Céline Degrande, Claude Duhr, Zhengwen Liu, Fabio Maltoni

An automated framework for BSM phenomenology that allows one to compute Feynman rules from a Lagrangian.

External collaborators: Céline Degrande (CERN) Benjamin Fuks (Jussieu).
Higgs phenomenology at the LHC
Fabio Maltoni

We study the Vector Boson Fusion production channel for the Higgs boson and other particles at the LHC, mainly focusing on the role of QCD corrections.
Loop-induced processes in the SM and Beyond
Fabio Maltoni, Olivier Mattelaer

Automation within MadGraph5_aMC@NLO and phenomenological studies of loop-induced processes for the LHC
MadGraph5_aMC@NLO
Fabio Maltoni, Olivier Mattelaer

Monte Carlo development.

External collaborators: Benjamin Fuks, Kentarou Mawatari, Kaoru Hagiwara, Tim Stelzer, Stefano Frixione, Marco Zaro, Rikkert Frederix, Valentin Hirschi, Paolo Torrielli, Johan Alwall, Hua-Sheng Shao, Mihailo Backovic,...
Search for nonresonant Higgs boson pair production in the llbb+MET final state
Christophe Delaere, Martin Delcourt, Vincent Lemaitre, Fabio Maltoni

The discovery of a Higgs boson (H) by the ATLAS and CMS experiments fixes the value of the self-coupling λ in the scalar potential whose form is determined by the symmetries of the Standard Model and the requirement of renormalisability. Higgs boson pair production is sensitive to the self-coupling and will play a major role in investigating the scalar potential structure.

This project consists in a search for nonresonant Higgs boson pair production via gluon fusion in the final state with two leptons, two b jets and missing transvere energy – gg → H(bb) H(WW) asking for the leptonic decay of the W's. The analysis is conducted in close collaboration with phenomenologists to ensure the approach is theoretically sound and future-proof.
Study of processes with heavy quarks in the initial state
Fabio Maltoni

The difference between predictions obtained with a massive scheme, where a heavy quark is treated as a finale massive state and the massless scheme, where the heavy quark is viewed as an initial parton may be extremely sizable. The aim of the project is to gain a better understanding of the size of the collinear logarithms arising when a heavy quark is treated as a final massive state and to investigate its kinematical origin.

External collaborators: Maria Ubiali, Giovanni Ridolfi.

Non-active projects
Publications in CP3
All my publications on Inspire

Number of publications as CP3 member: 110 Download BibTeX

Last 5 publications

2019

CP3-19-16: Top-quark electroweak interactions at high energy
Fabio Maltoni, Luca Mantani, Ken Mimasu

Refereed paper. April 11.
CP3-19-02: A Monte Carlo global analysis of the Standard Model Effective Field Theory: the top quark sector
Hartland, Maltoni, Nocera, Rojo, Slade, Vryonidou, Zhang

72 pages, to be submitted to JHEP
Refereed paper. January 17.

2018

CP3-18-82: Top-quark effects in diphoton production through gluon fusion at NLO in QCD
Fabio Maltoni, Manoj K. Mandal, and Xiaoran Zhao

Refereed paper. December 20.
CP3-18-70: Event generation for beam dump experiments
L. Buonocore, C. Frugiuele, F. Maltoni, O. Mattelaer, F. Tramontano

to be submitted
Refereed paper. December 3.
CP3-18-69: Probing the scalar potential via double Higgs boson production at hadron colliders
Borowka, Sophia and Duhr, Claude and Maltoni, Fabio and Pagani, Davide and Shivaji, Ambresh and Zhao, Xiaoran

[Abstract] [PDF] [Journal]
Refereed paper. November 29.

More publications