Holographic gauge mediation via strongly coupled messengers

TL;DR

The paper addresses calculable gaugino masses in a gauge mediation setup with a strongly coupled hidden sector by exploiting gauge/gravity duality. It analyzes a holographic realization based on a cascading gauge theory with a non-SUSY near-tip deformation of the Klebanov-Strassler geometry and probe D7-branes for the visible sector, focusing on the regime where messenger mass $m_{\chi}$ is close to the confinement scale $\Lambda_{\varepsilon}$. The main finding is that the leading gaugino mass arises from SUSY-breaking perturbations of the 3-form flux $G_{3}$, with the result scaling as $\delta m_{1/2} \sim g_{\mathrm{vis}}^{2}\,\lambda\left(\Lambda_{\varepsilon}\right) \frac{\Lambda_{\mathcal{S}}^{4}}{\Lambda_{\varepsilon}^{3}} \left[\left(\frac{m_{\chi}}{\Lambda_{\varepsilon}}\right)^{3/2}-1\right]^{3/2}$, up to model-dependent factors. The analysis shows that holography can fully capture the contributions from strongly coupled messenger quarks in this regime, while 5-form flux and spin-connection effects do not provide leading-order corrections. This work highlights a regime where calculable soft terms emerge from strongly coupled dynamics, with implications for model building and the understanding of SUSY-breaking mediation at strong coupling.

Abstract

We consider a relative of semi-direct gauge mediation where the hidden sector exists at large 't Hooft coupling. Such scenarios can be difficult to describe using perturbative field theory methods but may fall into the class of holographic gauge mediation scenarios, meaning that they are amenable to the techniques of gauge/gravity duality. We use a recently found gravity solution to examine one such case where the hidden sector is a cascading gauge theory resulting in a confinement scale not much smaller than the messenger mass. In the original construction of holographic gauge mediation, as in other examples of semi-direct gauge mediation at strong coupling, the primary contributions to visible sector soft terms come from weakly coupled messenger mesons. In contrast to these examples, we describe the dual of a gauge theory where there are significant contributions from scales where the strongly coupled messenger quarks are the effective degrees of freedom. In this regime, the visible sector gaugino mass can be calculated entirely from holography.