Dirac Gauginos and Kinetic Mixing

TL;DR

Dirac gaugino masses are computed at leading order using analytic continuation in superspace and are shown to be intimately connected to kinetic mixing between gauge sectors, with explicit $F$-term and $D$-term formulas derived for both abelian and non-abelian gauginos. The work unifies field-theory and string-theory perspectives, showing how holomorphic mixing $ ext{χ}_h$ controls the physical Dirac mass $m_D$ and how moduli (including singlets) couple to D-terms to generate novel interactions that impact collider and dark-matter phenomenology. It provides concrete Type II string realizations, including a D-brane example that reproduces field-theory results and clarifies when leading-order Dirac masses can arise from F- or D-term sources, including non-perturbative effects. Overall, the paper equips model builders with practical, compact formulas linking Dirac gaugino masses to kinetic-mixing data, with broad implications for beyond-M MSSM constructions and their experimental signatures.

Abstract

We present formulae for the calculation of Dirac gaugino masses at leading order in the supersymmetry breaking scale using the methods of analytic continuation in superspace and demonstrate a link with kinetic mixing, even for non-abelian gauginos. We illustrate the result through examples in field and string theory. We discuss the possibility that the singlet superfield that gives the U(1) gaugino a Dirac mass may be a modulus, and some consequences of the D-term coupling to the scalar component. We give examples of possible effects in colliders and astroparticle experiments if the modulus scalar constitutes decaying dark matter.