A phenomenological profile of the Higgs boson

A discussion is given of the production, decay and observability of the scalar Higgs boson H expected in gauge theories of the weak and electromagnetic interactions such as the Weinberg-Salam model. After reviewing previous experimental limits on the mass of the Higgs boson, a speculative cosmological argument for a small mass is given. If its mass is similar to that of the pion, the Higgs boson may be visible in the reactions π-p→Hn or γp→Hp near threshold. If its mass is < approximately 300 MeV, the Higgs boson may be present in the decays of kaons with a branching ratio O(10-7), or in the decays of one of the new particles: 3.7 → 3.1 + H with a branching ratio O(10-4). If its mass is <=4 GeV, the Higgs boson may be visible in the reaction pp→H + X, H→μ+μ-. If the Higgs boson has a mass <=2msub(μ), the decays H→e+e- and H→γγ dominate, and the lifetime is O(6 x 10-4 to 2 x 10-12)seconds. As thresholds for heavier particles (pions, strange particles, new particles) are crossed, decays into them become dominant, and the lifetime decreases rapidly to O(10-20) sec for a Higgs boson of mass 10 GeV. Decay branching ratios in principle enable the quark masses to be determined. (Auth.)