Title: Exploring physics beyond the Standard Model to understand dark matter and other outstanding issues

Speaker: Tanmoy Mondal (Osaka University)

Abstract: There is mounting evidence that the Standard Model(SM) of particle physics is incomplete. In this seminar, I will discuss some of the outstanding issues of the Standard Model. First, I will discuss astrophysical signatures of dark matter (DM) in a model agnostic way and what kind of new physics we can observe. Such astrophysical signatures can establish the particle nature of DM and are independent of any specific DM genesis mechanism. In general, to stabilize a DM particle, a stabilizing symmetry is assumed, which is often not well motivated. Next, I will discuss the freeze-in decaying dark matter model without a stabilizing symmetry, where the DM phenomenology is intertwined with neutrino mass generation. Finally, I will briefly discuss a scalar extension of the SM, which can explain the newly observed muon anomalous magnetic moment. However, in a UV complete scenario, such scalar extensions are strongly constrained, leaving a small parameter space. Future lepton colliders can be crucial in exploring such models.