Split symmetries

TL;DR

This paper constructs a six-dimensional supergravity model with orbifold compactification that naturally produces three generations, breaks gauge symmetry to the Standard Model, and results in a split supersymmetry-like spectrum with heavy sfermions.

Contribution

It introduces a novel orbifold compactification of 6D supergravity with magnetic flux that generates three generations and achieves gauge symmetry breaking to the Standard Model.

Findings

Three quark-lepton generations from magnetic flux

Heavy squarks and sleptons compared to other superpartners

Realization of split supersymmetry scenario

Abstract

We consider six-dimensional supergravity with gauge group $SO(10)\times U(1)_A$, compactified on the orbifold $T^2 / \mathbb{Z}_2$. Three quark-lepton generations arise as zero modes of a bulk $\bf16$-plet due to magnetic flux of the anomalous $U(1)_A$. Boundary conditions at the four fixed points break $SO(10)$ to subgroups whose intersection is the Standard Model gauge group. The gauge and Higgs sector consist of "split" $SO(10)$ multiplets. As consequence of the $U(1)_A$ flux, squarks and sleptons are much heavier than gauge bosons, Higgs bosons, gauginos and higgsinos. We thus obtain a picture similar to "split supersymmetry." The flavor structure of the quark and lepton mass matrices is determined by the symmetry breaking at the orbifold fixed points.