Search for hadronic decays of a light Higgs boson in the radiative decay Upsilon --> gamma A0

TL;DR

This study searches for a light Higgs boson decaying hadronically in radiative Upsilon decays using BABAR data, setting upper limits on the product of branching fractions due to no observed signal.

Contribution

It provides the first experimental upper limits on hadronic decays of a light Higgs in Upsilon radiative decays across a range of masses.

Findings

No significant signal observed.

Upper limits on product branching fractions set between 1e-6 and 8e-5.

Constraints improve previous bounds on light Higgs decays.

Abstract

We search for hadronic decays of a light Higgs boson (A0) produced in radiative decays of an Upsilon(2S) or Upsilon(3S) meson, Upsilon --> gamma A0. The data have been recorded by the BABAR experiment at the Upsilon(3S) and Upsilon(2S) center of mass energies, and include (121.3 \pm 1.2) x 10^6 Upsilon(3S) and (98.3 \pm 0.9) x 10^6 Upsilon(2S) mesons. No significant signal is observed. We set 90% confidence level upper limits on the product branching fractions B(Upsilon(nS)-->gamma A0) x B(A0-->hadrons) (n=2 or 3) that range from 1 x 10^{-6} for an A0 mass of 0.3 GeV/c^2 to 8 x 10^{-5} at 7 GeV/c^2.