IP2I

Soutenance de thèse Elise Jourd'huy " Measurement of Higgs Boson Pair Production with CMS Using LHC Run II and Run III Data "
2025-11-04 14:00 - 16:00 (Europe/Paris)

Soutenance de thèse de David Amran : " Study of the fundamental symmetries of the Standard Model"
2025-10-24 10:00 - 12:00 | amphi dirac, 4, rue enrico fermi, Villeurbanne, 69622, France

Soutenance de thèse Nicolas Martini : Vers une mesure du CEvNS avec l'expérience RICOCHET à l'ILL : développement, installation et premiers résultats".
2025-10-17 14:00 - 16:00

Soutenance de thèse de Laura Parrado Ospina: "Compétition entre les mécanismes de relaxation post-collisionels du dimère de méthanol protoné
2025-10-17 09:00 - 13:00

Soutenance de thèse de Yann Monceaux : Mésons B, Facteurs de Forme et signes de Nouvelle Physique
2025-10-16 14:00 - 16:00

Soutenance de thèse Mattia Verzeroli : "Environmentally Friendly Gas Mixtures and Monitoring Systems for LHC Detectors"
2025-10-15 14:00 - 16:00

Soutenance de thèse de Amazigh Ouzriat : “Search for Compact Binary Coalescences during the First Part of the Fourth LIGO-Virgo-KAGRA Observing Run"
2025-09-30 10:00 - 12:00 | amphi dirac, 4, rue enrico fermi, Villeurbanne, 69622, France

Soutenance de thèse de Madeline Ginolin " Impact des biais astrophysiques associés aux supernovae de Type Ia sur la mesure des paramètres cosmologiques »
2025-09-12 16:00 - 18:00 | amphi dirac, 4, rue enrico fermi, Villeurbanne, 69622, France

Highlight on the X17 - Claudio Toni: "The X17 from the Atomki anomalies to the recent PADME result"
2025-06-17 11:00 - 12:00 | Dirac/RdC-Amphithéâtre (IP2I)
In view of the experimental anomalies observed by the Atomki collaboration, we critically re-examine the possible theoretical interpretation of them in terms of a new BSM boson X with mass around 17 MeV. Employing a low-energy effective field theory, we estimate the range of values of the nucleon couplings to the new light state in order to match the experimental observations, with the aim of identifying the viable spin/parity assignments. We then discuss the recent results from MEG-II and PADME searches.
https://indico.in2p3.fr/event/36380/

Nuclear Phenomenology - Pierre Arthuis: "The ab initio endeavour: Describing the nuclear chart from the ground up"
2025-01-17 14:30 - 15:30 | Dirac/RdC-Amphithéâtre (IP2I)
Ab initio methods for low-energy nuclear physics have vastly improved their range both in terms of isotopes and observables of interest over the past two decades [1]. Driven by formal and numerical advances, this progress now allows them to tackle phenomena from spectroscopy to deformation, from neutrinoless double-beta decay to reactions of astrophysical interest.In this talk, I will introduce ab initio methods as a set of consistent yet different approaches that all tackle nuclear phenomenology from inter-nucleonic interactions anchored in chiral Effective Field Theory. I will then review a set of diverse recent results from groups all over the world. Finally, I will focus on recent progress in the design of nuclear interactions and how it paves the way to exciting experimental efforts at radioactive ion beam facilities while connecting to nuclear astrophysics [2].[1] H. Hergert, A Guided Tour of ab initio Nuclear Many-Body Theory, Front. Phys. 8, 379 (2020)[2] P. Arthuis, K. Hebeler & A. Schwenk, Neutron-rich nuclei and neutron skins from chiral low-resolution interactions, arXiv:2401.06675 (2024)
https://indico.in2p3.fr/event/34909/

Nouvelles Approches de Machine Learning pour la Caractérisation des Détecteurs AGATA et Étude de la Structure Nucléaire des Isotopes de Niobium Riches en Neutrons
2024-12-12 14:00 - 16:00 | Amphi Paul Dirac, 4, rue enrico fermi, Villeurbanne, 69622, France
Soutenance de thèse de Mojahed Sameer Moh’D ABUSHAWISH — groupe Matière Nucléaire

Topical Review - Raffaele T. D'Agnolo: "Naturalness for Gen Z"
2024-11-29 11:00 - 12:00 | Amphi Dirac (IP2I)
The value of the Higgs mass is one of the biggest mysteries in particle physics. In the past decades a set of experiments with unprecedented energy and sensitivity have been built to test its explanations. The absence of positive signals suggests that the guiding principles of the field might have been misleading. However, the question remains valid and existing experimental results have only made it sharper and harder to solve. Giving up on this problem cannot be done without giving up the Wilsonian picture of particle physics that underlies our whole understanding of Nature and our tremendous success in describing it. I will review the problem, its solutions and the unavoidable questions raised by its relation to the cosmological constant problem.
https://indico.in2p3.fr/event/34143/

Étude et développement de nouveaux détecteurs bas-seuils pour la recherche de matière noire légère avec CRYOSEL
2024-11-28 10:00 - 12:00 | Amphi Paul Dirac, 4, rue enrico fermi, Villeurbanne, 69622, France
Soutenance de thèse d’Elsa GUY — Groupe Manoir

Theory - Rhameez S. Herbst: "The Eigenvalues of Laplace Operators: From Analytical to Machine Learning Approaches"
2024-11-25 14:00 - 15:00 | Croix Rousse (IP2I)
In this presentation, eigenvalue problems are investigates. With particular focus on the eigenvalues of Laplace operators, we explore the analytical and numerical approaches to finding eigenfunction-eigenvalue pairs. While considerable detail is devoted to the analytical methods in their relation to how the solution is derived we use this as a means of demonstrating how numerical methods deviate from this practice. Lastly, the effectiveness of Machine Learning techniques, such as PINNS, is discussed and a few test problems are presented.
https://indico.in2p3.fr/event/34179/

Recherche d'une résonance se désintégrant en un quark top et un boson de Higgs dans un état final dileptonique même signe avec les données Run 2 de l'expérience CMS au LHC
2024-11-21 10:00 - 12:00 | amphi dirac, 4, rue enrico fermi, Villeurbanne, 69622, France
Soutenance de thèse de Benjamin BLANCON — Groupe CMS

Alejandro Perez : "Gravité Quantique et Matière noire : Une histoire d'avant le big bang"
2024-11-20 16:00 - 17:00 | Amphi Gouy (Bât. Lippmann)
La gravité quantique et ses applications possibles pour les trous noirs et la cosmologie.
https://indico.in2p3.fr/event/34586/

Highlight on Toponium - Afiq Anuar: "In Search of Spin-0 Resonances Decaying to Top Quark-Antiquark Pairs"
2024-11-07 14:00 - 15:00 | Amphi Dirac (IP2I)
The CMS Collaboration has recently publicized a search for heavy pseudoscalar or scalar bosons decaying to a top quark pair in final states with one or two charged leptons, using 138 fb-1 of proton-proton collisions at √s = 13 TeV. In this search, an excess of the data above the background prediction, as modeled using perturbative quantum chromodynamics only, is observed with a significance of above five standard deviations.In my presentation, I will discuss the properties of the excess as established within the scope of the search. This includes its position, which is close to the top pair production threshold, as well as its spin quantum numbers. In addition, I will discuss interpretations of the data in terms of a 1S0[1] bound state of top quark pairs, whose modelling is extremely challenging despite its formation being a prediction of the standard model, and in terms of a generic spin-0 boson whose resonant production interferes with the top pair continuum. I will also discuss this result in a wider context, in particular the interplay between it and existing experimental measurements.
https://indico.in2p3.fr/event/34332/

Mesures de la multiplicité des particules chargées vers l'avant et de la dépendance de la production des J/ψ vers l'avant avec la multiplicité en collisions pp, avec l'expérience ALICE au LHC
2024-10-24 09:00 - 11:00 | amphi dirac, 4, rue enrico fermi, Villeurbanne, 69622, France
Soutenance de thèse de Sarah HERRMANN — Groupe ALICE

Cosmologie avec les sirènes sombres et populations de binaires de trous noirs avec les ondes gravitationnelles de LIGO-Virgo-KAGRA
2024-10-03 10:00 - 12:00 | amphi dirac, 4, rue enrico fermi, Villeurbanne, 69622, France
Soutenance de thèse de Grégoire Pierra — groupe Ondes Gravitationnelles

Propriétés de la matière dense dans le cadre du modèle chiral avec confinement
2024-09-18 09:00 - 11:00 | Amphi Paul Dirac – IP2I
Soutenance de thèse de Mohamad CHAMSEDDINE — groupe Théorie

Johannes Jahan: The MUSES project
2024-06-19 14:00 - 15:00 | Amphi Dirac (IP2I)
The will to provide a complete picture for the phase diagram of nuclear matter has led researchers from nuclear physics, neutron stars and heavy-ion communities to join efforts by creating the Modular Unified Solver of the Equation of State (MUSES) project. This theoretical collaboration aims at delivering a cyber-infrastructure modular tool, which offers the possibility to get a wide set of observables from several equations of states, over different regions of the phase diagram. It gathers hence many different approaches that can be used to address some of the most active research topics of these times: exploring the large density region of the phase diagram, searching for the existence of a critical point of nuclear matter, or studying neutron star properties through gravitational waves detection.We present here the main goals and features of the MUSES project, giving insights into the different features and models planned to be accessible, as well as the different functionalities to be provided.Seminar by Johannes Jahan (University of Houston, USA) =================Open to all IP2I & LMA members, as well as UCBL and CNRS students and collaborators. More information on seminars: https://intranet.ip2i.in2p3.fr/vie-scientifique/seminaires-ip2iIP2I agenda: https://www.ip2i.in2p3.fr/agendav2/
https://indico.in2p3.fr/event/33352/

Exploring Proton Structure and QCD with the LHC
2024-06-13 14:00 - 15:00 | Amphi Dirac (IP2I Lyon), 4, rue enrico fermi, Villeurbanne, 69622, France
Speakers: Bugra Bilin (Université Libre de Bruxelles)
The Large Hadron Collider (LHC) at CERN provides data shedding light to a previously unexploited territory. Despite the absence of discoveries beyond the Higgs boson towards new physics, the wealth of information gleaned from these experiments has sparked a renewed interest in unraveling the mysteries of the Standard Model. In this seminar, we embark on an exploration of proton structure and the subtle intricacies of Quantum Chromodynamics (QCD) extending to these unprecedented territories, and we will walk through several LHC precision measurements that provides stringent tests. We will also walk through the indispensable role of Monte-Carlo simulations in modeling soft and hard QCD processes. =================Open to all IP2I & LMA members, as well as UCBL and CNRS students and collaborators. More information on seminars: https://intranet.ip2i.in2p3.fr/vie-scientifique/seminaires-ip2iIP2I agenda: https://www.ip2i.in2p3.fr/agendav2/
https://indico.in2p3.fr/event/33038/

Black holes and their perturbations in the search for new physics
2024-06-11 14:00 - 16:00 | amphi dirac, 4, rue enrico fermi, Villeurbanne, 69622, France
Soutenance de thèse d’Anna CHRYSOSTOMOU — groupe Theorie

Justine Zeghal: Simulation-Based Inference: estimating posterior distributions without analytic likelihoods
2024-05-24 14:00 - 15:00 | Amphi Dirac (IP2I)
Galaxy surveys have already made it possible to probe our universe and improve our understanding of it. Upcoming stage IV surveys (such as LSST or Euclid) are expected to be larger and deeper offering the opportunity to refine our estimations even further. To analyze the vast amount of data these surveys will produce and enable new discoveries, we need to update our inference techniques for constraining cosmological parameters. To date, inference techniques typically rely on suboptimal compression of data (most of the time, into the power spectrum) and the use of a Gaussian likelihood function.
Recently, there has been a promising shift from analytical likelihood-based approaches to simulations-based inference. This new paradigm allows for precise inference, enabling to extract all the information embedded in the data, even when the likelihood of the data given the parameters is unknown.
In my presentation, I will explain the two ways of performing inference using a simulation model, whether it is explicit (when you can evaluate the likelihood of your simulation model) or implicit (when you only have simulations). I will discuss the pros and cons of these techniques specifically regarding the number of simulations they need. I will use the example of weak gravitational lensing, but the inference method remains the same in any case!
Seminar by Justine Zeghal (Laboratoire Astroparticule & Cosmologie, Paris)
=================
Open to all IP2I & LMA members, as well as UCBL and CNRS students and collaborators.
More information on seminars: https://intranet.ip2i.in2p3.fr/vie-scientifique/seminaires-ip2i
IP2I agenda: https://www.ip2i.in2p3.fr/agendav2/
https://indico.in2p3.fr/event/33158/

Cosmic strings and dark matter in the axiverse
2024-05-06 14:00 - 15:00 | Tete d’Or (IP2I Lyon)
Speakers: Quentin Bonnefoy (Université de Strasbourg – IPHC)
I will discuss cosmic strings associated with axions arising from extra-dimensional gauge fields, with a focus on their impact on axion dark matter. Unlike more common 4D setups, the string cores are fundamentally singular, demanding a UV-complete description to make sense of their properties and cosmology. I will take it to be the string theory axiverse, for which one finds that the presence of cosmic strings can lead to overproduction of axion dark matter regardless of the axion mass. I will then argue that the multiple axions of the axiverse alleviate that conclusion, and that future gravitational waves observatories might probe this scenario.
https://indico.in2p3.fr/event/33041/

Caractérisation et modélisation du miroir dichroïque du télescope spatial Euclid
2024-05-03 14:00 - 16:00 | Amphi Paul Dirac, 4, rue enrico fermi, Villeurbanne, 69622, France
Soutenance de thèse de Maël BARON – LMA – Cosmologie

Veronique Boisvert: Looking for beauty using truth: top and bottom quark results from ATLAS
2024-04-19 14:30 - 15:30 | Salle Croix-Rousse (3e) (IP2I Lyon)
The top quark is the heaviest particle observed so far and as such plays a fundamental role in the electroweak symmetry breaking mechanism. The LHC has produced very large datasets of top quark pair events as well as single top events. The ATLAS and CMS collaborations have a very extensive program of top quark physics probing precision QCD calculations, anomalous couplings and new physics searches. I will report on measurements of the top quark using the ATLAS detector at the LHC. In particular I will mostly cover recent top quark mass measurements done by ATLAS, including a method using a muon from a semileptonic decay of a b-hadron meson. I will also discuss how this method was also used at 8 TeV to perform novel measurements of CP-violation in the b-quark sector. This is currently being updated by ATLAS with the full Run 2 dataset at 13 TeV. Seminar by Veronique Boisvert (Royal Holloway, University of London) =================Open to all IP2I & LMA members, as well as UCBL and CNRS students and collaborators. More information on seminars: https://intranet.ip2i.in2p3.fr/vie-scientifique/seminaires-ip2iIP2I agenda: https://www.ip2i.in2p3.fr/agendav2/
https://indico.in2p3.fr/event/31223/

Veronique Boisvert: The Climate Emergency: can Particle Physics ever be sustainable?
2024-04-19 11:00 - 12:00 | Amphi Dirac (IP2I Lyon), 4, rue enrico fermi, Villeurbanne, 69622, France
We live in a climate emergency and consequently all countries are putting in place measures to reduce their carbon emissions in order to reach a so-called “net zero emissions” by 2050. All aspects of economic life will be affected by such measures, including particle physics research. I will present some examples of sources of carbon emissions within the field of particle physics. This will include emissions associated with building and running accelerators, detector operations, high-performance computing and activities associated with our research life like travel. I will also present solutions being developed for addressing this in the near and long term as well as recommendations for the field. Seminar by Veronique Boisvert (Royal Holloway, University of London) =================Open to all IP2I & LMA members, as well as UCBL and CNRS students and collaborators. More information on seminars: https://intranet.ip2i.in2p3.fr/vie-scientifique/seminaires-ip2iIP2I agenda: https://www.ip2i.in2p3.fr/agendav2/
https://indico.in2p3.fr/event/31222/

PHDAYS
2024-04-18 09:00 - 17:30, 2024-04-16 09:00 - 17:00
