Journal Club

In the search for physics beyond the Standard Model (SM), long-lived particles (LLPs) have emerged as promising signatures and are being actively explored in ongoing experiments. In this talk, I explore searches for a light scalar LLP produced in rare B-meson decays at future colliders. I present complementary strategies at FCC-ee and FCC-hh, including the physics case for the proposed forward detector FOREHUNT (FORward Experiment for HUNdred TeV) at a 100 TeV FCC-hh. For FCC-ee, I assess the sensitivity of the proposed IDEA (Innovative Detector for an Electron-Positron Accelerator) detector across several benchmark scenarios. Different LLP decay final states are analyzed, together with a careful treatment of long-lived Standard Model backgrounds. These results demonstrate the strong discovery potential for light, weakly coupled scalars at next-generation collider facilities.