Contact
Fabio Maltoni
Position
Academic staff
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
Université catholique de Louvain
2, Chemin du Cyclotron - Box L7.01.05
B-1348 Louvain-la-Neuve
Belgium
Phone
+32 10 47 3166
Office
Personal homepage
UCL member card
Teaching at UCL
Quantum Mechanics
Relativistic Quantum Mechanics
Electroweak interactions
Strong interactions and symmetries
Seminars of theoretical and mathematical physics
Relativistic Quantum Mechanics
Electroweak interactions
PHY2224
Introduction to the Standard Model of the electroweak interactions.
22.5h, 4 ECTS (shared with J.M.Gerard)
Introduction to the Standard Model of the electroweak interactions.
22.5h, 4 ECTS (shared with J.M.Gerard)
Strong interactions and symmetries
Seminars of theoretical and mathematical physics
PHY2501
Invited lectures on special topics.
15h, 2 ECTS.
Invited lectures on special topics.
15h, 2 ECTS.
People responsibilities
Postdocs
PhD students
Master students
Visitors
Former members
Christopher Flett
My main activity at present is the implementation of quarkonium cross sections in the well-known event generator MadGraph5_aMC@NLO. The aim is to provide an efficient, all-encompassing tool that anyone can use to simulate quarkonium production at colliders and be versatile enough to handle final states with multiple quarkonium production in association with elementary particles. This will ultimately facilitate the first global NRQCD phenomenological analyses comparing theory and experiment, and enable sound physics-case constructions for current (LHC@CERN, Belle-II@KEK, RHIC@BNL,…) and future (EIC@BNL, FCC@CERN, …) experimental programs. In addition, I work on exclusive heavy-quarkonium production, with a focus on applying this knowledge to the gluon parton distribution function at moderate-to-low momentum fractions and scales, as well as contributing to future global generalised parton distribution extractions.
My main activity at present is the implementation of quarkonium cross sections in the well-known event generator MadGraph5_aMC@NLO. The aim is to provide an efficient, all-encompassing tool that anyone can use to simulate quarkonium production at colliders and be versatile enough to handle final states with multiple quarkonium production in association with elementary particles. This will ultimately facilitate the first global NRQCD phenomenological analyses comparing theory and experiment, and enable sound physics-case constructions for current (LHC@CERN, Belle-II@KEK, RHIC@BNL,…) and future (EIC@BNL, FCC@CERN, …) experimental programs. In addition, I work on exclusive heavy-quarkonium production, with a focus on applying this knowledge to the gluon parton distribution function at moderate-to-low momentum fractions and scales, as well as contributing to future global generalised parton distribution extractions.
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.).
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.
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.
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.
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.
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
Samuel Abreu
(Postdoc
in IRMP from October 2018 to October 2021)
Johan Alwall
(Postdoc
in IRMP from October 2005 to September 2006)
Current position: Postdoc at SLAC, Stanford (US). Since 1st Jan 2010, Postdoc at FNAL.
Current position: Postdoc at SLAC, Stanford (US). Since 1st Jan 2010, Postdoc at FNAL.
Federico Ambrogi
(Visitor
in IRMP)
Rafael Aoude
(Postdoc
in IRMP from October 2020 to September 2023)
Pierre Artoisenet
(Postdoc
in IRMP)
Mihailo Backovic
(Postdoc
in IRMP)
Zemrije Beca
(Administrative staff
in IRMP)
Matteo Becchetti
(Postdoc
in IRMP from March 2019 to February 2021)
Olga Bessidskaia Bylund
(Visitor
in IRMP)
Francesca Borzumati
(Visitor
in IRMP)
Diogo Buarque Franzosi
(Postdoc
in IRMP)
Xavier Calmet
(Postdoc
in IRMP from January 2008 to September 2009)
Current position: Permanent at University of Sussex (UK).
Current position: Permanent at University of Sussex (UK).
Eugenia Celada
(Visitor
in IRMP)
Andrew Cheek
(Postdoc
in IRMP from October 2019 to September 2021)
Riccardo Costa
(Master student
in IRMP from September 2016 to January 2017)
Antonio Costantini
(Postdoc
in IRMP)
Goutam Das
(Visitor
in IRMP from September 2015 to December 2015)
Priscila de Aquino
(Visitor
in IRMP from October 2008 to October 2013)
Karen De Causmaecker
(Visitor
in IRMP)
Arthur Dedieu
(Intern
in IRMP)
Antonio Del donno
(Master student
in IRMP)
Federico Demartin
(PhD student
in IRMP)
Nicolas Deutschmann
(PhD student
in IRMP)
Veronika Fedotova
(Master student
in IRMP)
Marco Feliciangeli
(PhD student
in IRMP from September 2007 to September 2011)
Roshan Foadi
(Visitor
in IRMP)
Roberto Franceschini
(Visitor
in IRMP from October 2017 to January 2018)
Rikkert Frederix
(PhD student
in IRMP from December 2005 to September 2009)
Current position: Post-doc in Zurich
Current position: Post-doc in Zurich
Lucchetti Gian Marco
(Intern
in IRMP)
Phillip Grajek
(Visitor
in IRMP)
Keith Hamilton
(Postdoc
in IRMP from October 2007 to August 2009)
Current position: Post-doc in Milan, Italy
Current position: Post-doc in Milan, Italy
Faten Hariri
(PhD student
in IRMP)
Kaoru Hawigara
(Visitor
in IRMP)
Jan Heisig
(Postdoc
in IRMP from October 2018 to September 2021)
Benoît Hespel
(PhD student
in IRMP)
Valentin Hirschi
(Visitor
in IRMP from September 2008 to January 2009)
Barthélemy Houben
(Master student
in IRMP)
Thomas in't Veld
(Visitor
in IRMP)
Stefan Krastanov
(Visitor
in IRMP from April 2013 to August 2013)
Prasanna Kumar Dhani
(Visitor
in IRMP)
Antoine Laureys
(PhD student
in IRMP from October 2009 to December 2012)
Will Link
(Visitor
in IRMP from September 2009 to March 2010)
David Lopez-Val
(Postdoc
in IRMP)
Jonathan Magerus
(Master student
in IRMP)
Benedikt Maier
(PhD student
in IRMP from March 2015 to June 2015)
Swarup Kumar Majee
(Postdoc
in IRMP from October 2008 to October 2010)
Current position: Post-doc at National Taiwan University
Current position: Post-doc at National Taiwan University
Manoj Kumar Mandal
(Postdoc
in IRMP)
Luca Mantani
(PhD student
in IRMP from September 2016 to August 2020)
Elisa Mariani
(PhD student
in IRMP)
Antony Martini
(PhD student
in IRMP)
Robin Marzucca
(PhD student
in IRMP from September 2015 to August 2019)
Daniele Massaro
(PhD student
in IRMP from May 2019 to October 2019)
Kentarou Mawatari
(Visitor
in IRMP)
Ken Mimasu
(Postdoc
in IRMP from October 2016 to August 2020)
Liam Moore
(Postdoc
in IRMP from December 2016 to November 2018)
Bettina Oexl
(Visitor
in IRMP)
Kiran Ostrolenk
(PhD student
in IRMP from April 2020 to July 2020)
Davide Pagani
(Postdoc
in IRMP)
Luca Pagani
(Visitor
in IRMP)
Nicolas Pierre
(Master student
in IRMP)
Antonio Santos
(Visitor
in IRMP)
Michele Selvaggi
(Research scientist
in IRMP)
Ambresh Shivaji
(Postdoc
in IRMP from September 2016 to September 2018)
Current position: Professor in India
Current position: Professor in India
Yoshitaro Takaesu
(Visitor
in IRMP from September 2011 to December 2011)
Ioannis Tsinikos
(Postdoc
in IRMP)
Maria Ubiali
(PhD student
in IRMP from September 2009 to August 2010)
Current position: Post-doc at Aachen University
Current position: Post-doc at Aachen University
Bram Verbeek
(PhD student
in IRMP from October 2015 to August 2019)
Stefan von Buddenbrock
(PhD student
in IRMP from February 2019 to May 2019)
Eleni Vryonidou
(Postdoc
in IRMP)
Ramon Winterhalder
(Postdoc
in IRMP from September 2021 to August 2024)
Cen Zhang
(Postdoc
in IRMP)
Xiaoran Zhao
(PhD student
in IRMP from April 2017 to September 2020)
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:
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:
- 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.
- provide the experimentalists at the colliders with the means to simulate events occurring at the energy frontier.
Projects
Research directions:
Experiments and collaborations:
Active projects
Non-active projects
Data analysis in HEP, astroparticle and GW experiments
Particle Physics
Phenomenology of elementary particles
Particle Physics
Phenomenology of elementary particles
Experiments and collaborations:
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).
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.
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.
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).
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.
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
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,...
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.
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.
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
Advanced Multi-Variate Analysis for New Physics Searches at the LHC
Agni Bethani, Christophe Delaere, Luigi Favaro, Andrea Giammanco, Vincent Lemaitre, Fabio Maltoni
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 have been part of AMVA4NewPhysics, a network of European institutions whose goal is to foster the development and exploitation of Advanced Multi-Variate Analysis for New Physics searches. The network offered between 2015 and 2019 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.
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 have been part of AMVA4NewPhysics, a network of European institutions whose goal is to foster the development and exploitation of Advanced Multi-Variate Analysis for New Physics searches. The network offered between 2015 and 2019 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.
Advanced Techniques for Fast Simulation and Data Analysis in High Energy Physics (ASAP)
Giacomo Bruno, Jérôme de Favereau, Christophe Delaere, Pavel Demin, Andrea Giammanco, Vincent Lemaitre, Fabio Maltoni, Olivier Mattelaer
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.
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.
ALOHA
Fabio Maltoni, Olivier Mattelaer
Create a code to create automatically HELAS routine in various format from the Feynman Rules.
Create a code to create automatically HELAS routine in various format from the Feynman Rules.
Automatic Matrix Element method and associated analyses techniques
Vincent Lemaitre, Fabio Maltoni, Olivier Mattelaer
Madweight is a algorithm to automatically reweight experimental events with the squared matrix element, and therefore provides the required computation techniques for a practical application of the matrix element method.
We also study the usefullness of MadWeight to estimate differential cross-section
via the marginal distributions of the the experimental weights 
.
External collaborators: Pierre Artoisenet (Ohio state university).
Madweight is a algorithm to automatically reweight experimental events with the squared matrix element, and therefore provides the required computation techniques for a practical application of the matrix element method.
We also study the usefullness of MadWeight to estimate differential cross-section
via the marginal distributions of the the experimental weights .
External collaborators: Pierre Artoisenet (Ohio state university).
Collider signatures of a low scale gravity
Fabio Maltoni
Study of the potential effects (such as black hole production) of a low scale gravity at the LHC.
Study of the potential effects (such as black hole production) of a low scale gravity at the LHC.
Double seesaw mechanism and leptogenesis in SUSY SO(10) GUT
Fabio Maltoni
We construct a supersymmetric grand unified model where the leptogenesis under the gravitino constraint is successfully implemented after determining the parameters of the dominated double seesaw mechanism by fitting the available data on neutrino masses and mixings.
External collaborators: M. K. Parida (NISER), Amitava Raychaudhuri (HRI).
We construct a supersymmetric grand unified model where the leptogenesis under the gravitino constraint is successfully implemented after determining the parameters of the dominated double seesaw mechanism by fitting the available data on neutrino masses and mixings.
External collaborators: M. K. Parida (NISER), Amitava Raychaudhuri (HRI).
Extra-dimensional Collider signal at LHC
Fabio Maltoni
We are mainly concentrated here on the electroweak scalars and vector bosons production in the higher dimensional model.
External collaborators: Gautam Bhattacharyy (SINP), Anindya Datta (CU) and Amitava Raychaudhuri (HRI).
We are mainly concentrated here on the electroweak scalars and vector bosons production in the higher dimensional model.
External collaborators: Gautam Bhattacharyy (SINP), Anindya Datta (CU) and Amitava Raychaudhuri (HRI).
Graviton phenomenology at the LHC
Fabio Maltoni
To study graviton production through multi-jet final state processes at hadron colliders taking into account the following models: ADD, RS and a massless graviton model.
External collaborators: Qiang Li (Paul Scherrer Institut - PSI, Switzerland) and prof. Kaoru Hagiwara (KEK Theory Center and Sokendai, Japan).
To study graviton production through multi-jet final state processes at hadron colliders taking into account the following models: ADD, RS and a massless graviton model.
External collaborators: Qiang Li (Paul Scherrer Institut - PSI, Switzerland) and prof. Kaoru Hagiwara (KEK Theory Center and Sokendai, Japan).
Heavy colored particles + jets
Fabio Maltoni
QCD radiation in heavy colored particle production at the LHC is studied.
In collaboration with Johan Alwall (SLAC)
QCD radiation in heavy colored particle production at the LHC is studied.
In collaboration with Johan Alwall (SLAC)
Herwig++
Fabio Maltoni
Herwig++ will be one of two or three, work-horse, multi-purpose event generators used in the analysis of LHC data.
In collaboration with Prof. Bryan Webber (Cambridge), Prof. Mike Seymour (CERN), Dr. Peter Richardson (Durham), Dr. Stefan Gieseke (Karlsruhe), Dr. David Grellscheid (Durham).
Herwig++ will be one of two or three, work-horse, multi-purpose event generators used in the analysis of LHC data.
In collaboration with Prof. Bryan Webber (Cambridge), Prof. Mike Seymour (CERN), Dr. Peter Richardson (Durham), Dr. Stefan Gieseke (Karlsruhe), Dr. David Grellscheid (Durham).
Loop induced processes at the LHC
Fabio Maltoni
We study a general approach to make predictions in terms of event generator of production processes induced by loops, such as gg>H.
Non UCL collaborators: Rikkert Frederix (ETH-Zurich), Valentin Hirschi (EPL-Lausanne), Stefano Frixione (CERN).
Keywords: Monte Carlo simulations, LHC, Higgs
We study a general approach to make predictions in terms of event generator of production processes induced by loops, such as gg>H.
Non UCL collaborators: Rikkert Frederix (ETH-Zurich), Valentin Hirschi (EPL-Lausanne), Stefano Frixione (CERN).
Keywords: Monte Carlo simulations, LHC, Higgs
MadDipole: Automatic Dipole subtraction
Fabio Maltoni
Automatizing the Catani-Seymour dipole subtraction formalism for NLO in QCD calculations within the MadGraph/MadEvent framework. Both for the subtraction terms for the real and the virtual contributions.
External collaborators: Thomas Gehrmann and Nicolas Greiner.
Automatizing the Catani-Seymour dipole subtraction formalism for NLO in QCD calculations within the MadGraph/MadEvent framework. Both for the subtraction terms for the real and the virtual contributions.
External collaborators: Thomas Gehrmann and Nicolas Greiner.
Modifications of the Higgs sector
Fabio Maltoni
We study modifications of the Higgs sector which involve Higgs bosons with anomalous scaling dimensions and/or hidden sectors.
We study modifications of the Higgs sector which involve Higgs bosons with anomalous scaling dimensions and/or hidden sectors.
Observability of a minimal extension of the scalar sectror: 2HDM at the LHC
Jean-Marc Gérard, Vincent Lemaitre, Fabio Maltoni
The goal of this work is to explore the phenomenology of a two Higgs doublet model with a custodial symmetry. It provides topologies that are unusual in the models usually considered in the literature. Notably, it opens the possibility of having an inverted mass spectrum with respect to MSSM with the lightest Higges being a pseudo-scalar and an heavier triplet of charged and neutral higgses.
External collaborators: Simon de Visscher (Zurich university).
The goal of this work is to explore the phenomenology of a two Higgs doublet model with a custodial symmetry. It provides topologies that are unusual in the models usually considered in the literature. Notably, it opens the possibility of having an inverted mass spectrum with respect to MSSM with the lightest Higges being a pseudo-scalar and an heavier triplet of charged and neutral higgses.
External collaborators: Simon de Visscher (Zurich university).
Phenomenology of Quantum Gravity
Fabio Maltoni
We study the renormalization of the Planck mass including quantum gravity effects and study potential experimental tests.
We study the renormalization of the Planck mass including quantum gravity effects and study potential experimental tests.
POWHEG
Fabio Maltoni
The POWHEG formalism of Prof. Paolo Nason allows the consistent combination of NLO calculations and parton shower simulations. We aim to exploit and realise this method for processes occuring in the LHC. Implementation of the method for various processes is a key part of the work. We are also interested in a general formulation of the method for automating 2->2 processes. Extensions of the method to NNLO, including realisations, are also to be addressed.
In collaboration with Prof. P.Nason (Milan), Dr. P.Richardson (Durham), J.Tully (Durham)
The POWHEG formalism of Prof. Paolo Nason allows the consistent combination of NLO calculations and parton shower simulations. We aim to exploit and realise this method for processes occuring in the LHC. Implementation of the method for various processes is a key part of the work. We are also interested in a general formulation of the method for automating 2->2 processes. Extensions of the method to NNLO, including realisations, are also to be addressed.
In collaboration with Prof. P.Nason (Milan), Dr. P.Richardson (Durham), J.Tully (Durham)
QCD and Twistors
Fabio Maltoni
The new approach from twistor spaces is applied to the study of the properties of multiparton amplitudes.
The new approach from twistor spaces is applied to the study of the properties of multiparton amplitudes.
Quarkonium
Fabio Maltoni
Production and decay of bound states of heavy quarks. Phenomenology and MC tools (MadOnia).
External Collaborators:
P. Artoisenet (Ohio), T. Stelzer (UIUC), J.P. Lansberg (Univ. Friburg, Germany), J. Campbell (Glasgow, UK), F. Tramontano (Univ. Napoli, Italy),...
Production and decay of bound states of heavy quarks. Phenomenology and MC tools (MadOnia).
External Collaborators:
P. Artoisenet (Ohio), T. Stelzer (UIUC), J.P. Lansberg (Univ. Friburg, Germany), J. Campbell (Glasgow, UK), F. Tramontano (Univ. Napoli, Italy),...
Renormalization group evolution and the neutrino physics
Fabio Maltoni
We are interested here to extract some new features of the neutrino physics with the use of renormalisation group equations.
External collaborators: Rathin Adhikari (CTP, JMI), Anindya Datta (CU).
We are interested here to extract some new features of the neutrino physics with the use of renormalisation group equations.
External collaborators: Rathin Adhikari (CTP, JMI), Anindya Datta (CU).
Simulation of events with QCD radiation
Fabio Maltoni
The aim of this project is to quantify the impact of using jet matching techniques in the context of the production of multi-jets processes, in the Standard Model and beyond. Such methods mix the PS simulation and the matrix-element calculation, leading notably to a strong reduction of the sensitivity to parton shower parameterization.
The aim of this project is to quantify the impact of using jet matching techniques in the context of the production of multi-jets processes, in the Standard Model and beyond. Such methods mix the PS simulation and the matrix-element calculation, leading notably to a strong reduction of the sensitivity to parton shower parameterization.
Top quark phenomenology
Fabio Maltoni
Top pair and single-top production is investigated, both for SM measurements and BSM searches.
External Collaborators:
J. Campbell (Glasgow, UK), F. Tramontano (Univ. Napoli, Italy),
+ E. Laenen (NIKHEF), S. Frixione (CERN), C. White (NIKHEF)
+ EXP group at CP3 (A. Giammanco, V. Lemaitre,...)
Top pair and single-top production is investigated, both for SM measurements and BSM searches.
External Collaborators:
J. Campbell (Glasgow, UK), F. Tramontano (Univ. Napoli, Italy),
+ E. Laenen (NIKHEF), S. Frixione (CERN), C. White (NIKHEF)
+ EXP group at CP3 (A. Giammanco, V. Lemaitre,...)
Top quark Physics
Fabio Maltoni
We study the phenomenology the top quark at colliders as well as at low energy via loops.
External collaborators: Christophe Grojean, Geraldine Servant, Scott Willenbrock, Benjamin Fuks.
We study the phenomenology the top quark at colliders as well as at low energy via loops.
External collaborators: Christophe Grojean, Geraldine Servant, Scott Willenbrock, Benjamin Fuks.
Vector boson + heavy flavors
Fabio Maltoni
Various SM backgrounds to new physics or SM measurements are considered.
* Z+heavy quarks + jets @ NLO
* W+heavy quarks + jets @ NLO
Collaborators: J. Campbell (Glasgow, UK), R.K. Ellis (Fermilab, US), S. Willenbrock (UIUC, US),
+ M.L. Mangano (CERN, Switzerland), F. Tramontano (Univ. Napoli, Italy),...
Various SM backgrounds to new physics or SM measurements are considered.
* Z+heavy quarks + jets @ NLO
* W+heavy quarks + jets @ NLO
Collaborators: J. Campbell (Glasgow, UK), R.K. Ellis (Fermilab, US), S. Willenbrock (UIUC, US),
+ M.L. Mangano (CERN, Switzerland), F. Tramontano (Univ. Napoli, Italy),...
Z' at the LHC
Fabio Maltoni
Study of vector boson (very peculiar) phenomenology at the LHC.
In collaboration with Francesco Tramontano (Univ. Napoli,IT) and Valentin Hirschi (EPL, CH)
Study of vector boson (very peculiar) phenomenology at the LHC.
In collaboration with Francesco Tramontano (Univ. Napoli,IT) and Valentin Hirschi (EPL, CH)
Publications in IRMP
All my publications on Inspire
Number of publications as IRMP member: 146
Last 5 publications
More publications
Number of publications as IRMP member: 146
Last 5 publications
2025
IRMP-CP3-25-34: Automated computation of spin-density matrices and quantum observables for collider physics
Valentin Durupt, Fabio Maltoni, Olivier Mattelaer
Refereed paper. October 20.
Refereed paper. October 20.
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.
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.
Refereed paper. May 31.
2024
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.
[Abstract] [PDF] [Local file] [Journal] [Dial]
Refereed paper. October 22.
More publications
2024
IRMP-CP3-24-17: Top-quark pair production as a probe of light top-philic scalars and anomalous Higgs interactions
Maltoni, Fabio and Pagani, Davide and Tentori, Simone
[Abstract] [PDF] [Local file] [Journal] [Dial]
Refereed paper. June 10.
[Abstract] [PDF] [Local file] [Journal] [Dial]
Refereed paper. June 10.
2023
IRMP-CP3-23-74: Probing Higgs-muon interactions at a multi-TeV muon collider
Eugenia Celada,Tao Han, Wolfgang Kilian,Nils Kreher, Yang Ma, Fabio Maltoni, Davide Pagani, Jurgen Reuter, Tobias Striegl, and Keping Xie.
[Abstract] [PDF] [Local file] [Journal] [Dial]
Refereed paper. December 17.
[Abstract] [PDF] [Local file] [Journal] [Dial]
Refereed paper. December 17.
IRMP-CP3-23-71: Phenomenology of superheavy decaying dark matter from string theory
Rouzbeh Allahverdi, Chiara Arina, Marco Chianese, Michele Cicoli, Fabio Maltoni, Daniele Massaro and Jacek K. Osinski
[Local file]
Refereed paper. November 30.
[Local file]
Refereed paper. November 30.
IRMP-CP3-23-69: Top-philic ALP phenomenology at the LHC: the elusive mass-window
Blasi, Simone and Maltoni, Fabio and Mariotti, Alberto and Mimasu, Ken and Pagani, Davide and Tentori, Simone
[Abstract] [PDF] [Local file] [Journal] [Dial]
Refereed paper. November 27.
[Abstract] [PDF] [Local file] [Journal] [Dial]
Refereed paper. November 27.
IRMP-CP3-23-34: Quantum SMEFT tomography: Top quark pair production at the LHC
Aoude, Rafael and Madge, Eric and Maltoni, Fabio and Mantani, Luca
[Abstract] [PDF] [Local file] [Journal] [Dial]
Refereed paper. July 2.
[Abstract] [PDF] [Local file] [Journal] [Dial]
Refereed paper. July 2.
IRMP-CP3-23-33: Resummation effects in the bottom-quark fragmentation function
Maltoni, Fabio and Ridolfi, Giovanni and Ubiali, Maria and Zaro, Marco
[Abstract] [PDF] [Local file] [Journal] [Dial]
Refereed paper. July 2.
[Abstract] [PDF] [Local file] [Journal] [Dial]
Refereed paper. July 2.
IRMP-CP3-23-32: Quantum information and CP measurement in H->tau+tau- at future lepton colliders
Altakach, Mohammad Mahdi and Lamba, Priyanka and Maltoni, Fabio and Mawatari, Kentarou and Sakurai, Kazuki
[Abstract] [PDF] [Local file] [Journal] [Dial]
Refereed paper. July 2.
[Abstract] [PDF] [Local file] [Journal] [Dial]
Refereed paper. July 2.
2022
IRMP-CP3-22-56: MadNIS -- Neural Multi-Channel Importance Sampling
2021
CP3-21-64: Studying dark matter with MadDM: lines and loops
Daniele Massaro, Chiara Arina, Jan Heisig, Fabio Maltoni and Olivier Mattelaer
[Abstract] [PDF] [Local file]
Proceedings of the "17th International Conference on Topics in Astroparticle and Underground Physics" (TAUP 2021).
Contribution to proceedings. November 12.
[Abstract] [PDF] [Local file]
Proceedings of the "17th International Conference on Topics in Astroparticle and Underground Physics" (TAUP 2021).
Contribution to proceedings. November 12.
CP3-21-62: Single top production in association with a WZ pair at the LHC in the SMEFT
Hesham El Faham, Fabio Maltoni, Ken Mimasu, Marco Zaro
[Abstract] [PDF] [Local file] [Journal] [Dial]
Refereed paper. November 4.
[Abstract] [PDF] [Local file] [Journal] [Dial]
Refereed paper. November 4.
2020
2019
CP3-19-02: A Monte Carlo global analysis of the Standard Model Effective Field Theory: the top quark sector
2018
2017
2016
2015
CP3-15-25: Higher-order QCD predictions for dark matter production at the LHC in simplified models with s-channel mediators
2014
CP3-14-18: The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
CP3-14-12: The Top Quark
Liss, T. , Maltoni, F., and Quadt, A.
[Full text]
52 pages, to be published in the Review of Particle Physics (PDG).
Refereed paper. February 6.
[Full text]
52 pages, to be published in the Review of Particle Physics (PDG).
Refereed paper. February 6.
2013
2012
2011
CP3-11-14: An effective approach to same sign top pair production at the LHC and the forward-backward asymmetry at the Tevatron
2010
2009
2008
CP3-08-77: MadGraph/MadEvent: A multipurpose event generator
Michel Herquet, Fabio Maltoni
[Full text]
Published in Nucl.Phys.Proc.Suppl.179-180:211-217,2008
Contribution to proceedings. December 31.
[Full text]
Published in Nucl.Phys.Proc.Suppl.179-180:211-217,2008
Contribution to proceedings. December 31.
CP3-08-43: Radiation of Extra-Jets in Inclusive SUSY Samples
Simon de Visscher, Johan Alwall, Fabio Maltoni
[Full text]
Proceeding for the talk of S. de Visscher at SUSY08 conference
Contribution to proceedings. September 15.
[Full text]
Proceeding for the talk of S. de Visscher at SUSY08 conference
Contribution to proceedings. September 15.
2007
2006