Constraints on the Higgs-boson masses in left-right electroweak gauge theories

We consider the minimal left-right-symmetric electroweak model and characterize the range of allowable masses for the physical Higgs boson. We use two approaches: (1) We compute the lowest-order boson-boson scattering amplitude and impose a unitarity constraint on the J=0 partial-wave amplitude; (2) we compute the radiative corrections to the Higgs-boson propagator and determine the range of Higgs-boson masses for which the perturbation series converges. Both methods give upper bounds on the Higgs-boson masses in terms of the gauge-boson masses, and we discuss the theoretical connection. The generalizations of these constraints and their applicability in light of previous bounds is examined.