Holographic Gauge Mediation

TL;DR

This work constructs and analyzes a holographic realization of gauge mediation in a warped throat, where SUSY breaking is localized by anti-D3 branes at the tip and communicated to the MSSM through bulk gauginos living on D7-brane flavor stacks. The leading SUSY-breaking effect arises from splittings in the tower of messenger mesons, adjoint KK modes of the D7-branes, which generate gaugino masses at one loop via a semi-direct/gaugino-mediation mechanism, while scalar masses arise through RG running from the gaugino sector. Tree-level gaugino masses are absent in the DKM background, and the gaugino mass scales as $m_\lambda \\sim {t\over 16\pi^2} {\mathcal{S} \over \mu^2} \sqrt{4\pi \lambda_{\text{eff}}(\mu)}$, with the total contribution controlled by a finite KK tower cutoff. The model highlights a calculable gravity-dual approach to strongly coupled SUSY breaking and reveals stringent geometric constraints (e.g., Landau poles) that motivate orbifold extensions to slow RG running and relax the constraints, potentially enabling viable phenomenology with sequestered gravity mediation as a subleading effect.

Abstract

We discuss gravitational backgrounds where supersymmetry is broken at the end of a warped throat, and the SUSY-breaking is transmitted to the Standard Model via gauginos which live in (part of) the bulk of the throat geometry. We find that the leading effect arises from splittings of certain "messenger mesons," which are adjoint KK-modes of the D-branes supporting the Standard Model gauge group. This picture is a gravity dual of a strongly coupled field theory where SUSY is broken in a hidden sector and transmitted to the Standard Model via a relative of semi-direct gauge mediation.

Figures (6)

• Figure 1: Quiver diagram for the conifold.
• Figure 2: Metastable $\overline{{\rm D3}}$-branes at the tip of the KS background.
• Figure 3: The SM gauge fields live in the worldvolume of D7-branes.
• Figure 4: Quiver diagram for the conifold flavored by Kuperstein D7-branes.
• Figure 5: Top: gravity dual. Bottom: running of the SM gauge coupling. Below $\mu$, the running is driven by the SM matter (SM running). Adjoint mesons can also affect the running above $\epsilon$ but, for clarity, we do not include them in the figure. Above $\mu$, the running is driven by the hidden sector (HS running), and the messengers $\chi$ and $\tilde{\chi}$ that connect the SM to the hidden sector start driving the SM to strong coupling. The beta function is constant within each period of the duality cascade (indicated with dashed lines).