LOWER-BOUND ON THE PSEUDOSCALAR MASS IN THE MINIMAL SUPERSYMMETRIC STANDARD MODEL

In the Higgs sector of the minimal supersymmetric standard model, the mass of the pseudoscalar A is an independent parameter together with t an beta=upsilon(2)/upsilon(1). If m(A) is small, then the process e(+) e(-)-->h+A is kinematically allowed and is suppressed only if tan beta is small, i.e., less than one. On the other hand, the mass of the cha rged Higgs boson is now near M-W, and the decay t-->b+h(+) is enhanced if tan beta<1. Since the former has not been observed, and the branch ing fraction of t-->b+W cannot be too small (by comparing the experime ntally derived It cross section from the leptonic channels with the th eoretical prediction), we can infer a phenomenological lower bound on m(A) of at least 60 GeV for all values of tan beta.