Yukawa-unified natural supersymmetry

Previous work on t − b − τ Yukawa-unified supersymmetry, as expected from SUSY GUT theories based on the gauge group SO(10), tended to have exceedingly large electroweak fine-tuning (EWFT). Here, we examine supersymmetric models where we simultaneously require low EWFT (“natural SUSY”) and a high degree of Yukawa coupling unification, along with a light Higgs scalar with mh ∼ 125 GeV. As Yukawa unification requires large tanβ ∼ 50, while EWFT requires rather light third generation squarks and low µ ≈ 100 − 250 GeV, B-physics constraints from BR(B → Xsγ) and BR(Bs → µ+µ−) can be severe. We are able to find models with EWFT ∆. 50 − 100 (better than 1–2 % EWFT) and with Yukawa unification as low as Ryuk ∼ 1.3 (30 % unification) if B-physics constraints are imposed. This may be improved to Ryuk ∼ 1.2 if additional small flavor violating terms conspire to improve accord with B-constraints. We present several Yukawa-unified natural SUSY (YUNS) benchmark points. LHC searches will be able to access gluinos in the lower 1 − 2 TeV portion of their predicted mass range although much of YUNS pa-rameter space may lie beyond LHC14 reach. If heavy Higgs bosons can be accessed at a high rate, then the rare H, A → µ+µ − decay might allow a determination of tanβ ∼ 50 as predicted by YUNS models. Finally, the predicted light higgsinos should be accessible to a linear e+e − collider with s ∼ 0.5 TeV