Do colored top partners exist below a few TeV?
In plain words
Most proposed fixes for the light Higgs predict a heavy cousin of the top quark (a top partner) that cancels the top quark's large push on the Higgs mass. If such particles exist, they should appear at colliders with masses not far above 1 TeV.
Precise statement
Determine whether colored states that cancel the top-loop contribution to $m_h^2$ (scalar stops in supersymmetry, vector-like fermionic top partners in composite-Higgs models) exist with mass $m_T < \sim 3\ \mathrm{TeV}$. Current LHC 13 TeV limits exclude stops up to about 1.2 to 1.3 TeV for a light neutralino and vector-like top partners up to roughly 1.5 TeV (approximate, model dependent).
What would settle it
Direct searches at the high-luminosity LHC ($3000\,\mathrm{fb}^{-1}$) and a future $100\,\mathrm{TeV}$ hadron collider covering pair production up to $m_T \sim 2\,\mathrm{TeV}$ and $\sim 10\,\mathrm{TeV}$ respectively.
Status in the literature
Unverified note
No signal through LHC Run 2; Run 3 at 13.6 TeV ongoing in 2026.
Related problems
- Special case of Why is the electroweak scale so far below the Planck scale?