MSSM parameters from supergravity backgrounds
Mariana Graña
TL;DR
This work constructs a concrete bridge between MSSM phenomenology and string compactifications by embedding the MSSM on a single D3-brane at a $Δ_{27}$ orbifold singularity and turning on SUSY-breaking background fluxes. It derives the non-Abelian D3-brane action in these flux backgrounds, connects gaugino, Higgsino, scalar masses, trilinear couplings, and dipole moments to flux parameters such as $G_0$, $G'_0$, $s_2$, and $\tau_2$, and analyzes the resulting soft terms within a no-scale structure context. The authors obtain a semi-realistic spectrum with TeV-scale SUSY breaking and discuss the requirements for leptons and the role of twisted moduli, demonstrating a viable route to relate MSSM features to brane-flux configurations. This framework enables quantitative studies of how bulk supergravity fields shape low-energy SUSY phenomenology in brane-world scenarios and can be extended to other compactifications with fluxes.
Abstract
We find the parameters of the MSSM in terms of bulk supergravity fields for the D-brane model of Berenstein, Jejjala and Leigh (hep-ph/0105042). The model consists of a D3-brane at the singularity of a non-abelian orbifold Δ_{27}, which gives the particles of the Supersymmetric Standard Model. We compute the action for the D-brane fields in the presence of both supersymmetric and supersymmetry breaking background fluxes. We get quark, lepton, gaugino, Higgsino, scalar partners and Higgs masses, as well as soft trilinear couplings, as functions of the background fields. This work develops a framework for connecting MSSM phenomenology to brane compactifications.