Search for a Low-Mass Higgs Boson in Υ(3S)→γA0, A0→τ+τ− at BABAR

Abstract

We search for a light Higgs boson A 0 in the radiative decay Υ ( 3 S ) → γ A 0 , A 0 → τ + τ − , τ + → e + ν e ¯ ν τ , or τ + → μ + ν μ ¯ ν τ . The data sample contains 122 × 10 6 Υ ( 3 S ) events recorded with the BABAR detector. We find no evidence for a narrow structure in the studied τ + τ − invariant mass region of 4.03 < m τ + τ − < 10.10 GeV / c 2 . We exclude at the 90% confidence level (C.L.) a low-mass Higgs boson decaying to τ + τ − with a product branching fraction B ( Υ ( 3 S ) → γ A 0 ) × B ( A 0 → τ + τ − ) > ( 1.5 - 16 ) × 10 − 5 across the m τ + τ − range. We also set a 90% C.L. upper limit on the τ + τ − decay of the η b at B ( η b → τ + τ − ) < 8 % .