Searching for New Phenomena with Flavor Physics: Quarks, Leptons & Neutrinos

by Florian Bernlochner (Uni Bonn)

Monday 26 May 2025, 15:00 → 17:00 Europe/Berlin

Something is at odds with our understanding of the Universe: although highly anticipated by our field, no new particles apart from the Higgs boson and exotic hadrons have materialized at the Large Hadron Collider (LHC). We have, however, good reasons to believe that our understanding of fundamental particles and their interactions is incomplete: for example, matter dominates the universe, astrophysical observations strongly suggest the existence of dark matter, neutrinos oscillate and therefore possess mass, and the strong force appears to be invariant under charge-parity transformations. The list goes on. In this presentation, I will touch on how we are trying to reveal cracks in the Standard Model of particle physics by studying the decay properties of heavy quarks at the Belle II experiment and by probing neutrinos and searching for feebly interacting particles at the FASER experiment. Belle II is a next-generation B-factory located in Tsukuba, Japan, just an hour north of Tokyo. The experiment aims to record an unprecedented number of beauty-quark decays in the clean environment of electron–positron collisions by the 2040s. It has just completed its first long shutdown to upgrade the pixel detector and is now on a mission to collect enough collision data for competitive measurements at the precision frontier. FASER is a small detector located about 480 meters downstream of the ATLAS experiment at CERN. It has started collecting its first dataset and aims to shed light on the long-lifetime frontier and explore the properties of neutrinos produced in LHC collisions. Both Belle II and FASER promise to provide new insights, and I firmly believe that our greatest discoveries still lie ahead of us. Let’s embark together on a journey to explore why — and glimpse what may come next.