Contact
Name
Fabio Maltoni

Position
Academic staff

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
https://maltoni.web.cern.ch

UCL member card
https://www.uclouvain.be/en/people/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
Postdocs
Yang Ma
My main research interest lies in elementary particle physics theory, focusing on high-energy collider physics as well as connections to astro-particle physics and cosmology. While the Standard Model (SM) of particle physics provides a remarkably successful description of elementary matter and forces, it fails to address a number of outstanding conceptual and empirical mysteries, such as the naturalness of electroweak scale, the strong CP problem, the nature of dark matter (DM), and the origin of neutrino masses. Clearly the SM must be extended and become part of a deeper structure that will explain these shortcomings, with new physics beyond the SM expected to emerge at some high energy scale. I aim to test the SM itself and search for possible new physics at high-energy colliders such as the Large Hadron Collider (LHC) and other future collider programs (ILC, CLIC, CEPC/SPPC, FCC-ee/hh, muon colliders, etc.).

PhD students
Tommaso Armadillo (member since January 2022)
I am working on the development of methods and tools to advance our ability to perform precision studies at colliders and apply them to key novel computations. In particular, we aim at introducing new techniques for two-loop integrals that are currently the bottleneck of next-to-next-to-leading order (NNLO) electroweak and use them to obtain predictions for Drell-Yan process at the LHC and for ZH production at future electron-positron colliders.
Valentin Durupt (UCL-FSR) (member since October 2024)
Studying particle physics phenomenology at colliders, Standard Model and Beyond with Effective Field Theory framework. Specialising in the use of Quantum Information (QI) observables (such as entanglement) to study fundamental interactions and their interpretation as QI processes.
Leonardo Satrioni (IISN - IISN THEORY) (member since May 2025)
Simone Tentori (member since January 2023)
I study particle physics phenomenology in colliders, both SM and BSM, with particular attention to top-philic interaction and light new states.
Zeqiang Wang
I am currently engaged in research on future collider projects, including the Future Circular Collider (FCC-ee) and the muon collider. My work focuses on g-2 and tau-related studies, as well as investigations into the electron Yukawa coupling.

Master students

Visitors

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:
Data analysis in HEP, astroparticle and GW experiments
Particle Physics
Phenomenology of elementary particles

Experiments and collaborations:
CMS

Active projects
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, 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
MadGraph suite of software
Fabio Maltoni, Olivier Mattelaer

CP3 is coordinating and leading the development of the MadGraph suite of tools. Tools use for the simulation of High-Energy Physics collision.
This project includes:
- NLO computation
- MadNIS: Neural Importance Sampler (AI for the phase-space integration)
- HardWare: How to port the code on modern facility (GPU, quantum computer, ...)

External collaborators: Benjamin Fuks, Kentarou Mawatari, Kaoru Hagiwara, Tim Stelzer, Stefano Frixione, Marco Zaro, Rikkert Frederix, Valentin Hirschi, Paolo Torrielli, Hua-Sheng Shao, Richard Ruiz, Ramon Witherhalder, Tilman Plhen,...
Search for nonresonant Higgs boson pair production in the llbb+MET final state
Agni Bethani, Christophe Delaere, 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 IRMP
All my publications on Inspire

Number of publications as IRMP member: 145
Last 5 publications

2025

IRMP-CP3-25-22: Double neutral-current corrections to NLO electroweak leptonic cross sections
Stefano Frixione, Fabio Maltoni, Davide Pagani, Marco Zaro

Refereed paper. May 31.
IRMP-CP3-25-21: Precision phenomenology at multi-TeV muon colliders
Stefano Frixione, Fabio Maltoni, Davide Pagani, Marco Zaro

Refereed paper. May 31.

2024

IRMP-CP3-24-32: Quantum tops at circular lepton colliders
Maltoni, Fabio and Severi, Claudio and Tentori, Simone and Vryonidou, Eleni

[Abstract] [PDF] [Journal] [Dial]
Refereed paper. October 22.
IRMP-CP3-24-31: Quantum detection of new physics in top-quark pair production at the LHC
Maltoni, Fabio and Severi, Claudio and Tentori, Simone and Vryonidou, Eleni

[Abstract] [PDF] [Local file] [Journal] [Dial]
Refereed paper. October 22.
IRMP-CP3-24-29: Higgs-muon interactions at a multi-TeV muon collider
Yang Ma, Eugenia Celada, Tao Han, Wolfgang Kilian, Nils Kreher, Fabio Maltoni, Davide Pagani, Jürgen Reuter,Tobias Striegl and Keping Xie

[Abstract] [PDF]
Contribution to proceedings. October 9.

More publications