String Phenomenology: A Top-Down Approach to Phenomenology and the Swampland Program

by Prof. Alon Faraggi

Wednesday 16 Apr 2025, 16:00 → 17:00 Europe/Rome

0M03

With the discovery of the Higgs boson at the LHC, the experimental confirmation of the Standard Particle Model is complete. I argue that the Standard Model indicates the realisation of unification structures in nature. String theory is a perturbatively consistent theory of quantum gravity that replicate these unification structures and produces benchmark models to study the phenomenology of the Standard Model and unification within a consistent theory of quantum gravity. In particular, the string constructions can be used to study the favour structure of the SM which is facilitated due to the existence of fundamental scalar Higgs representations in the massless string spectrum. A pivotal question from an experimental point of view is whether the Higgs is fundamental or composite.  The string constructions also give rise to different BSM scenarios, like dark matter , axions, extra gauge symmetries, and dark energy models. Given this breadth, I propose that from a string phenomenology perspective, the experimental particle physics priority is the nature of the Higgs boson and the electroweak symmetry breaking mechanism. The optimal facility in the near future to study this sector is a hadron collider at 50–60TeV that utilises contemporary magnet technology and can be built in 10–15 years from decision. Additionally, I will discuss the imprint of string worldsheet symmetries, like mirror symmetry and spinor-vector duality, in the effective field theory limit, and the top-down approach that they provide for the "Swampland" program.