Does the Higgs field give the electron its mass? · revision history

Revision 2

Accepted · core change · record

Changes against revision 1:

Title
Does the Higgs field give the electron its mass?
Plain
The electron couples to the Higgs so weakly (strength about 3 in a million) that the coupling has never been detected. Measuring it would show whether the Higgs field is the source of the mass of the particle that sets the size of atoms.
Precise · changed · core
Revision 1: Measure the electron Yukawa coupling $y_e$ (SM value $\sqrt{2}\,m_e/v \sim 2.9e-6$), or $\kappa_e = y_e/y_e^{\mathrm{SM}}$. The best direct bound, CMS $\operatorname{BR}(H \to e+ e-) < 3.0e-4$ at 95 percent CL (Phys. Lett. B 846, 137783, 2023), corresponds to $\left|\kappa_e\right| < \sim 240$ (approximate, using $\operatorname{BR}_{\mathrm{SM}} \sim 5e-9$). An answer is $\kappa_e$ measured with $O(1)$ precision, enough to separate $\kappa_e = 1$ from $\kappa_e = 0$.
Revision 2: Measure the electron Yukawa coupling $y_e$ (SM value $\sqrt{2}\,m_e/v \sim 2.9 \times 10^{-6}$), or $\kappa_e = y_e/y_e^{\mathrm{SM}}$. The best direct bound, CMS $\operatorname{BR}(H \to e+ e-) < 3.0 \times 10^{-4}$ at 95 percent CL (Phys. Lett. B 846, 137783, 2023), corresponds to $\left|\kappa_e\right| < \sim 240$ (approximate, using $\operatorname{BR}_{\mathrm{SM}} \sim 5 \times 10^{-9}$). An answer is $\kappa_e$ measured with $O(1)$ precision, enough to separate $\kappa_e = 1$ from $\kappa_e = 0$.
Settled by
Resonant s-channel production $e+ e- \to H$ at $\sqrt{s}=m_{H}$ with a center-of-mass energy spread of about 4 MeV at FCC-ee, projected to reach $1.3\,\sigma$ for the SM coupling (an upper limit of 1.6 times $y_{e}^{\mathrm{SM}}$) per interaction point per year with $10\,\mathrm{ab}^{-1}$ (d'Enterria, Poldaru, Wojcik, Eur. Phys. J. Plus 137, 201, 2022, arXiv:2107.02686).
Kind
well-posed
Answer type
yes-no
References
(empty)
Literature status
open
Status note
Only upper bounds exist as of 2026; FCC-ee feasibility studies reach sensitivity near the SM value.
Posed since
(empty)

Decisions