Search for a light Higgs resonance in radiative decays of the Y(1S) with a charm tag

TL;DR

This paper searches for a light CP-odd Higgs boson in radiative Y(1S) decays with charm tagging, setting upper limits on the decay rates but finding no significant signal in the analyzed data.

Contribution

It provides the first search for a light Higgs in Y(1S) radiative decays with charm tagging, establishing new upper limits on the decay branching fractions.

Findings

No significant signal observed.

Upper limits on branching fractions range from 7.4 x 10^-5 to 2.4 x 10^-3.

Excluded mass regions between 8.95 and 9.10 GeV/c^2 due to background.

Abstract

A search is presented for the decay Y(1S) -> gamma A0, A0 -> cc-bar, where A0 is a candidate for the CP-odd Higgs boson of the next-to-minimal supersymmetric standard model. The search is based on data collected with the BABAR detector at the Y(2S) resonance. A sample of Y(1S) mesons is selected via the decay Y(2S) -> pi+pi-Y(1S). The A0 -> cc-bar decay is identified through the reconstruction of hadronic D0, D+, and D*(2010)+ meson decays. No significant signal is observed. The measured 90% confidence-level upper limits on the product branching fraction B(Y(1S) -> gamma A0) x B(A0 -> cc-bar) range from 7.4 x 10^-5 to 2.4 x 10^-3 for A0 masses from 4.00 to 8.95 GeV/c^2 and 9.10 to 9.25 GeV/c^2, where the region between 8.95 and 9.10 GeV/c^2 is excluded because of background from Y(2S) -> gamma chi_bJ(1P), chi_bJ(1P) -> gamma Y(1S) decays.