Search for di-muon decays of a light scalar Higgs boson in radiative Y(1S) decays

الأصل · EN

We search for di-muon decays of a low-mass Higgs boson (A⁰) in the fully reconstructed decay chain of Υ(2S,3S) → Υ(1S), Υ(1S) → A⁰, A⁰ →. The A⁰ is predicted by several extensions of the Standard Model (SM), including the Next-to-Minimal Supersymmetric Standard Model (NMSSM). NMSSM introduces a -odd light Higgs boson whose mass could be less than 10. The data samples used in this analysis contain 92.8 × 10⁶ Υ(2S) and 116.8 × 10⁶ Υ(3S) events collected by the detector. The Υ(1S) sample is selected by tagging the pion pair in the Υ(2S, 3S) → π+π-Υ(1S) transitions. We find no evidence for A⁰ production and set 90% confidence level (C.L.) upper limits on the product branching fraction B(Υ(1S) → A⁰) × B(A⁰ →) in the range of (0.28 - 9.7)× 10⁻⁶ for 0.212 ≤ mₐ₀ ≤ 9.20. We also combine our results with previous results of Υ(2S,3S) → A⁰, A⁰ → to set limits on the effective coupling (fΥ) of the -quark to the A⁰, fΥ² × B(A⁰ →), at the level of (0.29 - 40)× 10⁻⁶ for 0.212 ≤ mₐ₀ ≤ 9.2 GeV/c².