Abstract

In the MSSM , the gauginos are assumed to acquire Majorana masses after supersymmetry breaking. If the light spectrum is extended slightly to include chiral multiplets in the adjoint representation of the gauge group, they can instead acquire Dirac masses by pairing up with the fermionic components of these multiplets. Dirac gauginos have several interesting properties, not least that they can be significantly heavier than Majorana gauginos, without paying any price in naturalness; this becomes particularly interesting in the light of the null results of the 2011 LHC searches for superpartners. One good reason for a theory to contain Dirac gauginos is if it has an unbroken (approximate) R-symmetry. In string theory, the construction of models with adjoint chiral fields and (optionally) an unbroken R-symmetry poses different problems to constructing the MSSM , especially as the gauge couplings no longer unify unless further matter is present. I will discuss solutions to some of these problems within the context of F-theory.