Higgs boson masses in no-scale supergravity

Abstract

We explore the Higgs sector of the minimal supersymmetric “no-scale” unified model with the inclusion of radiative corrections which modify the usual tree-level Higgs mass relations. In the process, we rederive the complete allowed parameter space of the model using the one-loop effective potential. Our results can be compared with previous, generic analyses, where restrictive assumptions regarding low-energy supersymmetry breaking and squark mixing terms have been made. We find that in this class of models the lightest Higgs boson is always the lightest CP-even mass eigenstate (h), with m h ⪆M w for a large portion of the allowed parameters space, and m h max ≈ 115 GeV an absolute upper bound. For low values of m 1 2 (e.g., m 1 2 ⪅ 150 GeV ), the heavier Higgses (A, H, H +) lie mostly in the intermediate mass region ( M w−2 M z), and become increasingly heavier and degenerated as m 1 2 grows. Depending on the sign of μ, we obtained an upper bound on m 1 2 which leads to absolute upper bounds on all Higgs masses. Finally, we discuss the relevant Higgs decay signatures at LEP and hadron colliders which may reveal their existence.