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 mu-eV, 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.

Abstract:  The Dark Energy Spectroscopic Instrument (DESI) is undertaking a five-year survey spanning 14,000 square degrees of the sky, with the goal of mapping 40 million extragalactic redshifts. These observations aim to refine our understanding of the universe’s expansion history through Baryon Acoustic Oscillations (BAO) and the growth of cosmic structure via Full Shape analyses. In 2024, the DESI collaboration released BAO (April 4) and Full Shape (November 19) cosmology results from the Data Release 1 (DR1) sample, assembled from the first year of data taking (2021 - 2022). This presentation will introduce the instrument and the survey and review the BAO and Full Shape measurements derived from DR1. I will discuss the cosmological constraints on the Hubble parameter, neutrino masses, dark energy and modified gravity obtained using DR1 data independently and in combination with complementary probes such as the CMB, supernova and weak lensing datasets. I will conclude by outlining potential improvements for standard analyses and providing an outlook on upcoming DESI future results.

Slides: https://slides.com/arnauddemattia/marseille_november2024

Abstract: The $K^+ \rightarrow \pi^+ \nu \bar{\nu}$  decay is a golden mode for flavour physics. Its branching ratio is predicted with a high precision by the Standard Model to be less than $\mathcal{O}(10^{-10})$. This decay mode is highly sensitive to indirect effects of new physics up to the highest mass scales. The NA62 experiment at the CERN SPS is designed to study the $K^+ \rightarrow \pi^+ \nu \bar{\nu}$ decay, and provided the world’s most precise investigation of this decay using 2016-18 data. Building on this success, the first results from a significantly improved analysis of new data, taken in 2021-22 after beam-line and detector upgrades, are presented, as well as the combination with the 2016-18 results.

ISOLDE (Isotope Separator On-Line DEvice) is a radioactive ion beam facility at CERN. ISOLDE provides radioactive ion beams with high intensity and excellent emittance, at a wide range of energies including post-accelerated beams. The beams from ISOLDE are used in a very rich and diverse scientific programme with a focus on the physics of exotic nuclei, but extending to atomic and molecular physics, solid-state physics, material science and medical isotopes. This seminar will provide an introduction to the facility and illustrate some of the physics highlights for non-experts.