Editing Fundamental interaction (section)

=== Higgs interaction ===
Conventionally, the Higgs interaction is not counted among the four fundamental forces.<ref>{{cite web |title=fundamental force {{!}} Definition, List, & Facts |url=https://www.britannica.com/science/fundamental-interaction |website=Encyclopedia Britannica |access-date=22 March 2021 |language=en}}</ref><ref>{{cite web |title=The Standard Model |url=https://home.cern/science/physics/standard-model |website=CERN |access-date=22 March 2021 |language=en}}</ref>

Nonetheless, although not a [[gauge theory|gauge]] interaction nor generated by any [[diffeomorphism]] symmetry, the [[Higgs field]]'s cubic [[Yukawa interaction|Yukawa coupling]] produces a weakly attractive fifth interaction.  After [[spontaneous symmetry breaking]] via the [[Higgs mechanism]], Yukawa terms remain of the form
: <math>\frac{\lambda_i}{\sqrt 2} \bar{\psi} \phi' \psi = \frac{m_i}{\nu} \bar{\psi} \phi' \psi</math>,
with Yukawa coupling <math>\lambda_i</math>, particle mass <math>m_i</math> (in [[Electronvolt|eV]]), and Higgs [[vacuum expectation value]] {{val|246.22|u=GeV}}.  Hence coupled particles can exchange a [[virtual particle|virtual]] Higgs boson, yielding [[Yukawa interaction#Classical potential|classical potentials]] of the form
: <math>V(r) = - \frac{m_i m_j}{m_{\rm H}^2} \frac{1}{4\pi r} e^{-m_{\rm H}\, c\, r/\hbar}</math>,
with Higgs mass {{val|125.18|u=GeV}}. Because the [[reduced Compton wavelength]] of the [[Higgs boson]] is so small ({{val|1.576e-18|u=m}}, comparable to the [[W and Z bosons]]), this potential has an effective range of a few [[attometer]]s.  Between two electrons, it begins roughly 10<sup>11</sup> times weaker than the [[weak interaction]], and grows exponentially weaker at non-zero distances.