Light Stops in a minimal U(1)x extension of the MSSM

Understand

In order to reproduce the measured mass of the Higgs boson mh = 125GeV in the minimal supersymmetric standard model, one usually has to rely on heavy stops, increasing the fine tuning of the electroweak scale.

• By introducing a new gauge sector, the Higgs mass gets a tree-level contribution via a non-decoupling D-term, and mh = 125 GeV can be obtained with lighter stops.
• In this paper, we study the values of the stops masses needed to achieve the correct Higgs mass in a setup where the gauge group is extended by a single U(1)x interaction.
• We derive the experimental limits on the mass of the Z' gauge boson in this setup, then discuss how the stops masses vary as a function of the free parameters introduced by the new sector.