Théorie

The Alpha Magnetic Spectrometer (AMS) is a general purpose high energy particle detector, which was successfully deployed on the International Space Station on May 19, 2011. It conducts a unique, long-duration mission of fundamental physics research in space. To date, the detector has collected over 255 billion cosmic ray events. This talk presents the latest AMS measurements of cosmic ray elementary particles. The latest results up to the energies of few Tera-electronvolts reveal distinctive properties of particle fluxes and indicate the existence of a primary source of high-energy electrons and positrons, associated with either Dark Matter or an Astrophysical origin. AMS is poised to continue its mission through 2030, providing unique insights into the origins of cosmic ray matter and antimatter and exploring new physics phenomena within the cosmos.

The QCD axion, a fascinating hypothetical particle proposed about 50 years ago, might hold the key to explaining one of the universe’s lingering mysteries: why strong interactions don't seem to break CP symmetry. Perhaps more importantly, it remains one of the most exciting dark matter candidates. 

What would we give to see an even younger image of the Universe from relics of the Big Bang?  And how can one even imagine how to do that?  One of the most subtle and important discoveries in elementary particle physics was to find that the tiny neutral particles that Enrico Fermi called the neutrinos have mass.  This mass was discovered indirectly through an effect predicted by Bruno Pontecorvo, now probed to high precision by KM3Net.

Discussion of the paper 

Love numbers beyond GR from the modified Teukolsky equation
Pablo A. Cano
https://arxiv.org/pdf/2502.20185

Precise nuclear physics theories and models are playing an increasingly important role in neutrino physics. While this has long been recognized in low-energy neutrino experiments, recent advances in accelerator-based neutrino oscillation studies have further highlighted the importance of nuclear many-body effects. Modern experiments such as T2K and NOvA require accurate simulations of nucleon correlations, a necessity that will persist in future experiments like ORCA and IceCube-Upgrade, DUNE, and Hyper-Kamiokande.

Motivated by the phenomenology of MOND, we propose a theory based on a fundamental non Abelian Yang-Mills gauge field with gravitational coupling constant (a "graviphoton") emerging in a regime of weak acceleration, i.e. below the MOND acceleration scale. Using the formalism of the effective field theory and invoking a mechanism of gravitational polarization of the dark matter medium, we show that generic solutions of this theory reproduce the deep MOND limit without having to introduce in an ad hoc way an arbitrary function in the action.