Search for a light Higgs boson decaying to two gluons or ss-bar in the radiative decays of Y(1S)

Abstract

We search for the decay Y(1S) -> gamma A0, A0 -> gg or ss-bar, where A0 is the pseudoscalar light Higgs boson predicted by the next-to-minimal supersymmetric standard model. We use a sample of (17.6 +- 0.3)x 10^6 Y(1S) mesons produced in the BaBar experiment via e+e- -> Y(2S) -> pi+pi-Y(1S). We see no significant signal and set 90%-confidence-level upper limits on the product branching fraction B(Y(1S) -> gamma A0) x B(A0 -> gg or ss-bar) ranging from 10^-6 to 10^-2 for A0 masses in the range 0.5 to 9.0GeV/c^2.