Abstract: On 13^th February 2023, the KM3NeT neutrino telescope detected the most energetic neutrino candidate event ever observed, with a median neutrino energy of 220 PeV, and a 90% confidence interval from 72 PeV to 2.6 EeV. The discovery of a neutrino with such a high energy is a new milestone in neutrino astrophysics. KM3NeT is a neutrino telescope in the Mediterranean Sea still under construction. It consists of two sites: ARCA, in front of the coast of Sicily, and ORCA, offshore Toulon, with strong involvement of the CPPM KM3NeT group. While ORCA is optimised for neutrinos in the GeV energy regime, ARCA detects best neutrinos fom sub-TeV energies up to few PeV. KM3-230213A was observed by ARCA and at the time of the detection, 21 detection lines were in operation. Dedicated studies were performed to estimate the energy and the direction of the event. Its near horizontal direction make it highly improbable that KM3-230213A could be a background muon event, and the extreme energy makes it almost certainly being of astrophysical origin. However, the exact astrophysical origin remains uncertain. While it is very likely not produced within the Milky Way, several potential blazar counterparts exist within the directional uncertainty region, and other scenarios such as a cosmogenic origin are feasible too. In this seminar talk I will go into the details of the discovery of this extraordinary neutrino event as well as its potential origin.

Part 1:

In high-energy experiments, especially for those with high luminosity collider, data acquisition system is designed to be capable of handling large event rate and data size. Electronics devices with Application Specific Integrated Circuit (ASIC) and Field-Programmable-Gate-Array (FPGA) are essential to perform real-time processing on the data from particle detectors. In the entire data chain of DAQ system, the Front-End Electronics perform digitization on the analog data from detectors; the readout system collects and buffers the data from multiple detectors; and the trigger systems filter the data based on real-time reconstruction. We will give an overview of the data chain of DAQ, the design of each component, and the prospect of future upgrade in this field. 

Part 2:

The Belle II experiment is a flavor physics experiment conducted at the SuperKEKB e⁺e⁻ collider at KEK in Japan. Full-scale data acquisition began in 2019, and to date, the experiment has collected 575 fb⁻¹ of data. This dataset has been used for studying B meson decays to search for physics beyond the Standard Model. One of the important components of the experiment is the online DAQ system, which has been developed and operated to efficiently process the data generated by the Belle II detector in real time. In this talk, I will present an overview of the Belle II online DAQ system, its architecture, key functionalities, and performance for data-taking. I will also discuss the challenges encountered and ongoing improvements.

Résumé :

Les super-tempêtes géomagnétiques de 2024 et 2025, visibles jusqu’en Afrique, ont suscité un engouement mondial pour un phénomène d’une rare intensité. Les aurores représentent une opportunité unique de créer un lien entre l’émerveillement de tous et la recherche scientifique.

À travers les données d’instruments scientifiques et les images d’astronomes amateurs, cette conférence explore les mécanismes physiques des aurores polaires à basses latitudes, en mettant en lumière les défis qu’elles posent encore à notre compréhension des interactions entre le Soleil et la Terre.

Nous présenterons comment une collaboration enrichissante a été mise en place avec des élèves de lycée et des étudiants en physique, afin d'explorer des questions simples mais restées jusqu'ici sans réponse.

L’association F-HOU (Hands-On Universe, France) : Cette association s’inscrit dans le cadre de l’enseignement des sciences par l'astronomie et l’utilisation de nouvelles technologies, permettant d’attiser l’intérêt des élèves pour la science.

L'orateur : Astronome amateur et professeur à l'INSTN, Gilles utilise l’astronomie comme un outil pédagogique pour susciter l’intérêt pour les sciences et expliquer les sciences physiques. Il est à l’origine d’un projet financé par Aix-Marseille Université pour utiliser l’astronomie solaire dans les classes. Ce télescope solaire sera installé à l’Observatoire de Haute-Provence (OHP) et sera exploité du premier cycle scolaire et aux cycles universitaires en offrant des outils d’observation modernes, innovants et accessibles à tous.
À travers cette conférence, Gilles Barouch propose de partager un regard de physicien non spécialiste du domaine de la météorologie spatiale ou de la magnétohydrodynamique pour tenter de comprendre les phénomènes géomagnétiques majeurs visibles en France sur le cycle 25 du Soleil.

Abstract: The MAgnetized Disk and Mirror Axion eXperiment (MADMAX) is a future experiment aiming to detect dark matter axions from the galactic halo by resonant conversion to photons in a strong magnetic field. It uses a novel concept based on a stack of dielectric disks, called booster, to enhance the potential signal from axion-photon conversion over a significant mass range. In its final version, MADMAX will scan the uncharted QCD axion mass range around 100 μeV, favoured by post-inflationary theories. Several small scale prototypes have been tested these last three years, allowing to validate the dielectric haloscope novel concept and perform competitive axion and dark photon dark matter searches.
The seminar will give an overview of these results. The next foreseen steps will also be discussed, as well as the french contributions to the MADMAX project.