Journal Club Seminar: The Moonshine and LHC di-photon excess

Abstract:

The phenomenology of extra Z' models attracted substantial interest since the realisation in the mid-eighties that they are ubiquitous in string inspired models. However, the construction of string derived models that allow for a light Z' has proven to be challenging. The reason being that string derived models utilise the symmetry breaking pattern E6 -> SO(10) x U(1)_\zeta which makes the U(1)_\zeta symmetry anomalous and therefore cannot form a component of a low scale Z' symmetry. On the other hand suppression of left--handed neutrino masses indicates that the Z' symmetry that resides in SO(10) has to be broken at a high scale. I will describe the construction of string derived models that admit an anomaly free U(1)_\zeta. The models are self--dual under the spinor--vector duality symmetry that was observed in the classification of fermionic  orbifolds. I will describe this duality symmetry and explore its relation to moonshine symmetries in two dimensions. A generic signature of the class of low scale Z' models under consideration is via di-photon production at low scales.

Seminar Organizer: Walter Tangarife