New constraints on a light CP-odd Higgs boson and related NMSSM ideal Higgs scenarios

Recent BABAR limits on BR(Gamma(3S) -> gamma a -> gamma tau(+)tau(-)) and BR(Gamma(3S) -> gamma a -> gamma mu(+)mu(-)) provide increased constraints on the ab (b) over bar coupling of a CP-odd Higgs boson, a, with m(a) < M-Gamma(3S). We extract these limits from the BABAR data and compare to the limits previously obtained using other data sets, especially the CLEO-III BR(Gamma(1S) -> gamma -> tau(+)tau(-)) limits. Comparisons are made to predictions in the context of "ideal''-Higgs NMSSM scenarios, in which the lightest CP-even Higgs boson, h(1), can have mass below 105 GeV (as preferred by precision electroweak data) and yet can escape old LEP limits by virtue of decays to a pair of the lightest CP-odd Higgs bosons, h1 -> a(1)a(1), with m(a1) < 2m(B). Most such scenarios with m(a1) < 2m(tau) are eliminated, but the bulk of the m(a1) > 7.5 GeV scenarios, which are theoretically the most favored, survive. We also outline the impact of the new ALEPH LEP results in the e(+)e--> Z + 4 tau channel. For tan beta >= 3, only NMSSM ideal Higgs scenarios with mh(1) greater than or similar to 98 GeV and ma1 close to 2m(B) satisfy the ALEPH limits. For tan beta less than or similar to 2, the ALEPH limits are easily satisfied for the most theoretically preferred NMSSM scenarios, which are those with m(a1) close to 2m(B) and m(h1) similar to 90-100 GeV.