THE SUPERSYMMETRIC CHARGED HIGGS BOSON MASS AND LEP PHENOMENOLOGY

We calculate the leading radiative corrections, originating from top and bottom quark and squark loops, to the mass of the charged Higgs boson H +/- in the minimal supersymmetric standard model, which is given at the tree-level by m(H +/-)2 = m(W)2 + m(A)2, where A is the physical CP-odd Higgs boson. We find that these corrections are numerically small, at most a few GeV, for generic values of the parameters, although they can be large in some special regions of parameter space. Our study indicates that generically, if the H +/- are to be accessible to LEP II (m(H) +/- less than or similar to 90 GeV), then m(A) less than or similar to 40 GeV. In this case it is likely that m(A) < m(h), where h is the lighter CP-even Higgs boson, and quite possible that m(A) < m(h)/2. After including radiative corrections to the hAA vertex, we find that the h --> AA decay could dominate over h --> bbBAR or tau+tau-, thereby changing LEP Higgs search strategies.