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

Abstract

We search for the decay Υ ( 1 S ) → γ A 0 , A 0 → g g or s ¯ s , where A 0 is the pseudoscalar light Higgs boson predicted by the next-to-minimal supersymmetric Standard Model. We use a sample of ( 17.6 ± 0.3 ) × 10 6 Υ ( 1 S ) mesons produced in the BABAR experiment via e + e − → Υ ( 2 S ) → π + π − Υ ( 1 S ) . We see no significant signal and set 90%-confidence-level upper limits on the product branching fraction B ( Υ ( 1 S ) → γ A 0 ) ⋅ B ( A 0 → g g or s ¯ s ) ranging from 10 − 6 to 10 − 2 for A 0 masses in the range 0.5 - 9.0 GeV / c 2 .