SEZIONE DI FIRENZE
Seminario di Andrea Tesi:
Abstract: In this talk I will briefly introduce the QCD axion, its behavior as cold Dark Matter candidate, and the existing experimental probes. Later, motivated by the foreseen progress in axion detection experiments, I will focus on a model where the axion can have an exponentially large coupling to photons, relying on the "clockwork" mechanism. I will comment on the theoretical motivations of such mechanism and analyze the resulting axion phenomenology. As a bonus, the model predicts a large number of pseudo-scalars which can be light and observable at the LHC.
In the last part of the talk I will focus on the cosmological implication of long-lived topological defects originating from the rich structure of the model, with an emphasis on their contribution to the axion dark matter abundance and on a possible upper bound on the scale of new physics.