Search for a Low-Mass Scalar Higgs Boson Decaying to a Tau Pair in Single-Photon Decays of ϒ(1s)


We search for a low-mass scalar CP-odd Higgs boson, A⁰, produced in the radiative decay of the upsilon resonance and decaying into a τ⁺τ⁻ pair: ϒ(1S)→γA⁰. The production of ϒ(1S) mesons is tagged by ϒ(2S) π⁺π⁻ ϒ(1S) transitions, using a sample of (98.3 ± 0.9) x 10⁶ ϒ(2S) mesons collected by the BABAR detector. We find no evidence for a Higgs boson in the mass range 3.5 ≤ m_{A⁰} ≤ 9.2 GeV, and combine these results with our previous search for the tau decays of the light Higgs in radiative ϒ(3S) decays, setting limits on the coupling of A⁰ to the bb̅ quarks in the range 0.09-1.9. Our measurements improve the constraints on the parameters of the next-to-minimal-supersymmetric Standard Model and similar theories with low-mass scalar degrees of freedom.



Higgs bosons, Radioactive decay, Mass (Physics), Photon energy, Tau decay

"This work is supported by DOE and NSF (USA), NSERC (Canada), CEA and CNRS-IN2P3 (France), BMBF and DFG (Germany), INFN (Italy), FOM (The Netherlands), NFR (Norway), MES (Russia), MICIIN (Spain), and STFC (United Kingdom). Individuals have received support from the Marie Curie EIF (European Union), the A. P. Sloan Foundation (USA) and the Binational Science Foundation (USA-Israel)."


©2013 American Physical Society