Upper bound on the Higgs-boson mass in the standard model.

The electroweak model with one Higgs doublet is investigated when the mass of the Higgs particle is larger than the weak-interaction scale. It is shown that the SU(2) Higgs sector with spontaneously broken O(4) symmetry and perturbative gauge coupling becomes a trivial field theory at infinite cutoff. Around the trivial Gaussian fixed point, for finite cutoff, a low-energy effective theory is found with nontrivial couplings and mass generation from spontaneous symmetry breaking. We find an upper bound of M H ≈ 640 GeV on the mass of the Higgs particle with a lattice momentum cutoff 2π times larger than the Higgs-boson mass. PACS numbers: 14.80.Gt, 11.15.Ha