Each particle that couples to the Higgs field has an associated Yukawa coupling λ f. The coupling with the Higgs field for fermions gives an interaction term L Y u k a w a = − − λ λ f ψ ψ ¯ ¯ H ψ ψ , with ψ ψ being the Dirac field and H the Higgs field. Also, the mass of a fermion is proportional to its Yukawa coupling, meaning that the Higgs boson will couple most to the most massive particle. This means that the most significant corrections to the Higgs mass will originate from the heaviest particles, most prominently the top quark. By applying the Feynman rules, one gets the quantum corrections to the Higgs mass squared from a fermion to be: