Unified Maximally Natural Supersymmetry

Abstract

Maximally Natural Supersymmetry, an unusual weak-scale supersymmetric extension of the Standard Model based upon the inherently higher-dimensional mechanism of Scherk-Schwarz supersymmetry breaking (SSSB), possesses remarkably good fine tuning given present LHC limits. Here we construct a version with precision $SU(2{)}_{\mathrm{L}}\times U(1{)}_{\mathrm{Y}}$ unification: ${\sin }^2{\theta }_W(M_Z)\simeq 0.231$ is predicted to $\pm 2\%$ by unifying $SU(2{)}_{\mathrm{L}}\times U(1{)}_{\mathrm{Y}}$ into a 5D $SU(3{)}_{\mathrm{EW}}$ theory at a Kaluza-Klein scale of $1/R_5\sim 4.4\mathrm{TeV}$, where SSSB is simultaneously realised. Full unification with $SU(3{)}_{\mathrm{C}}$ is accommodated by extending the 5D theory to a $N=4$ supersymmetric $SU(6)$ gauge theory on a 6D rectangular orbifold at $1/R_6\sim 40\mathrm{TeV}$. TeV-scale states beyond the SM include exotic charged fermions implied by $SU(3{)}_{\mathrm{EW}}$ with masses lighter than $\sim 1.2\mathrm{TeV}$, and squarks in the mass range $1.4\mathrm{TeV}-2.3\mathrm{TeV}$, providing distinct signatures and discovery opportunities for LHC run II.

Comments: 33 pages, 7 figures