The B+ -> K+ nu nu decay is mediated by a flavor-changing neutral current, which makes this decay quite rare in the Standard Model, happening about 6 times every million B+ decays, according to the theory. Moreover, the presence of two undetected neutrinos in the final state and of only one visible charged track makes searching for this decay particularly challenging. 

We perform an analysis using electron-positron collisions recorded by the Belle II experiment between the years 2019 and 2022, using the properties of the accompanying B meson in the event to suppress background from other decays of the signal B candidate and light-quark pair production. We determine the branching fraction of the decay to be 2.7 sigma above the Standard Model expectation, providing the first evidence for this decay with a significance of 3.6 standard deviations.

Euclid is an ESA mission aiming at studying the geometry and nature of the dark Universe. Over a span of six years, Euclid will meticulously survey nearly 15,000 square degrees of the extragalactic sky. Equipped with optical capabilities spanning from 530 to 920 nanometers and near-infrared imaging in Y, J, and H bands, as well as slitless spectroscopy ranging from 1206 to 1892 nanometers, Euclid will capture detailed data on distant galaxies between redshift of 0.84 and 2. Launched successfully on July 1, 2023, Euclid was placed in orbit around the second Lagrange point where both of its cutting-edge instruments, the VIS and the NISP, underwent meticulous commissioning and calibration over the initial six months of the mission. As the Euclid survey commenced in February 2024, this presentation will provide insights into the mission's status at Lagrange 2 and showcase the initial scientific images and results captured by both instruments.

The Standard Model successfully describes the fundamental interactions of elementary particles up to TeV energies. Nonetheless, we know there is new physics beyond, although the energy scale at which it becomes manifest is unknown. The common belief is that new phenomena arise only at TeV energies or higher. However, much lighter particles could still be hiding due to their very weak interactions with known ones. Ultra-high precision measurements in atomic and molecular spectroscopy offer an interesting set of probes for such scenarios, complementing the efforts invested at high-energy colliders. In this presentation, we will explore two different approaches based on hydrogen spectroscopy and atomic clocks.

Document to collect questions:

https://docs.google.com/document/d/1_NEaFIEQfeKQCADn3IKZEznWSi6OYO5WGSslyQbe5-A/edit

The JUNO experiment located at Jiangmen in the south of China nearby Macau is primarily a reactor neutrino experiment at a baseline of 53 km. With a total target mass of 20 kt liquid scintillator, it can measure precisely the reactor neutrino spectrum to determine the mass hierarchy and to improve the precision of neutrino mixing parameters by an order of magnitude. It is one of the best experiment for supernova neutrinos, solar neutrinos and geoneutrinos, as well as searches for new physics. In this talk, I will report the design, the technology development and the construction status of the detector. Data taking of the JUNO experiment is expected to be around the end of this year. Possible upgrades in the future will be also discussed.

Wang Yifang is a Chinese particle and accelerator physicist. He is director of the Institute of High Energy Physics (IHEP) of the Chinese Academy of Sciences in Beijing and known for contributions to neutrino physics, in particular his leading role (with Kam-Biu Luk) at Daya Bay Reactor Neutrino Experiment to determine the last unknown neutrino mixing angle θ 13.
After earning his bachelor's degree in physics at Nanjing University (1984) he was with Samuel CC Ting at the L3 experiment the Large Electron-Positron Collider (LEP) of CERN. Wang worked and studied at the University of Florence obtaining PhD in Physics, then worked at Laboratory for Nuclear Science of the Massachusetts Institute of Technology and at Stanford University and joined the Institute of High Energy Physics(IHEP), China in 2001 as a researcher and became the Director in 2011.

Marie Curie, première femme lauréate du prix Nobel de physique, puis de chimie, première femme nommée professeur à la Sorbonne, a fait exploser de multiples plafonds de verre, quand ce n’étaient pas les murs de pierre de la société russe, puis française, puis internationale. Outre son activité de premier plan en physique, elle a pris de nombreuses initiatives novatrices moins connues comme  ses actions envers l’enseignement des sciences aux enfants, la médecine, son implication dans Commission Internationale de Coopération Intellectuelle (CICI), ancêtre de l’UNESCO, la formation de radiologues sur le front de la Grande Guerre… 
Cette conférence informelle s’adresse à tous, non-physiciens comme physiciens, curie-eux et curie-euses de l’histoire de notre science et de cette femme hors du commun.

The existence of nonbaryonic dark matter (DM) in the Universe is compelling, as suggested by astrophysical and cosmological observations. The most commonly assumed production mechanism for DM in the early universe corresponds to the weakly interacting massive particle (WIMP) paradigm, in which DM has mass and couplings at the electroweak scale. However, the current null experimental results and severe constraints on the natural parameter space are forcing us to search beyond the standard WIMP paradigm. In this talk, I will review alternative DM production mechanisms in the early universe, both thermal and non-thermal, like the FIMP and the SIMP paradigms. The possible impact of alternative non-standard cosmological scenarios will also be analyzed. Finally, experimental avenues for DM detection are discussed.

Document to collect questions:

https://docs.google.com/document/d/1_NEaFIEQfeKQCADn3IKZEznWSi6OYO5WGSslyQbe5-A/edit