A Little Solution to the Little Hierarchy Problem: A Vector-like Generation

TL;DR

Introducing a vector-like fourth generation in the MSSM provides a simple, natural solution to the little hierarchy problem, predicting new quarks within LHC reach and compatible with existing constraints.

Contribution

The paper proposes a minimal extension with a vector-like generation to address the little hierarchy problem while maintaining consistency with experimental data.

Findings

Higgs mass can naturally exceed 114 GeV with new quarks

Predicted quark masses between 300-600 GeV

Potential for discovery at the LHC

Abstract

We present a simple solution to the little hierarchy problem in the MSSM: a vector-like fourth generation. With O(1) Yukawa couplings for the new quarks, the Higgs mass can naturally be above 114 GeV. Unlike a chiral fourth generation, a vector-like generation can solve the little hierarchy problem while remaining consistent with precision electroweak and direct production constraints, and maintaining the success of the grand unified framework. The new quarks are predicted to lie between ~ 300 - 600 GeV and will thus be discovered or ruled out at the LHC. This scenario suggests exploration of several novel collider signatures.