The Potential Fate of Local Model Building

TL;DR

This paper investigates local F-theory GUT models at E_8, identifying two promising models with realistic features, but finds challenges in embedding them globally, highlighting limitations of local model building.

Contribution

It identifies two potentially realistic local models at E_8 with matter parity, but shows difficulties in their global embedding, questioning the predictive power of local approaches.

Findings

Two local models with realistic properties were identified.

Global embedding via spectral cover approach is not feasible for these models.

Local model building may have limited predictive power without global completion.

Abstract

We analyse local models at the point of E_8 in F-theory GUTs and identify exactly two models with potentially realistic properties concerning proton stability and a suitable pattern of quark and lepton masses. To this end we identify a matter parity at the local point. A globally consistent ultraviolet completion turns out to be problematic for both models. It is impossible to embed the models in a semilocal scheme via the spectral cover approach. This seems to severely limit the predictive power of local model building and to indicate that the full string theory might give us valuable hints for particle physics model building.