HEP In the literature: open

Why is the electroweak scale so far below the Planck scale?

In plain words

The Higgs field sets the masses of most particles at about $246\,\mathrm{GeV}$, roughly 1e17 times below the scale where gravity becomes strong. No known principle explains this huge gap without extreme fine cancellations.

Precise statement

In the SM with a cutoff $\Lambda$, the top loop gives $\delta m_h^{2} \sim -(3 y_t^{2}/(8 \pi^{2})) \Lambda^{2}$, so $m_h = 125\,\mathrm{GeV}$ with $\Lambda \sim M_{\mathrm{Pl}} \sim 1.2e19\,\mathrm{GeV}$ requires cancellation to about 1 part in 1e33. An answer is a mechanism (symmetry, compositeness, dynamics or selection) that yields $v = 246\,\mathrm{GeV}$ with at most mild tuning and is consistent with all LHC data.

What would settle it

Discovery at a collider of the particles or form factors predicted by a specific mechanism, or a calculable non-collider mechanism confirmed by its own distinct predictions.

Status in the literature

Unverified note

LHC Run 2 and early Run 3 data (to 2025) show no top partners, superpartners or composite resonances near 1 TeV, pushing simple natural models to percent-level tuning or worse.