Un-oriented Quiver Theories for Majorana Neutrons

TL;DR

This paper explores un-oriented open string theories where exotic instantons induce Majorana masses for neutrons, linking string theory models to observable phenomena like neutron-antineutron oscillations and potential LHC signatures.

Contribution

It introduces specific quiver models within string theory that generate Majorana neutron masses via non-perturbative effects, connecting high-energy theory with experimental prospects.

Findings

Majorana neutron masses can be generated by exotic instantons in string models.

Potential LHC signatures include color-triplet scalars or fermions detectable at current energies.

Models suggest links between neutron oscillations and collider physics, with possible Pati-Salam extensions.

Abstract

In the context of un-oriented open string theories, we identify quivers whereby a Majorana mass for the neutron is indirectly generated by exotic instantons. We discuss two classes of (Susy) Standard Model like quivers, depending on the embedding of SU(2)_W in the Chan-Paton group. In both cases, the main mechanism involves a vector-like pair mixing through a non-perturbative mass term. We also discuss possible relations between the phenomenology of Neutron-Antineutron oscillations and LHC physics in these models. In particular, a vector-like pair of color-triplet scalars or color-triplet fermions could be directly detected at LHC, compatibly with n-\bar{n} limits. Finally we briefly comment on Pati-Salam extensions of our models.