Search for a Light CP -odd Higgs Boson and Low-Mass Dark Matter at the Belle Experiment
Journal
Physical Review Letters
Journal Volume
122
Journal Issue
1
Date Issued
2019
Author(s)
Seong I.S. et al.
Vahsen, S.E.
Adachi, I.
Aihara, H.
Al Said, S.
Asner, D.M.
Aulchenko, V.
Aushev, T.
Ayad, R.
Babu, V.
Bakich, A.M.
Bansal, V.
Abstract
We report on the first Belle search for a light CP-odd Higgs boson, A0, that decays into low mass dark matter, χ, in final states with a single photon and missing energy. We search for events produced via the dipion transition (2S)→ (1S)π+π-, followed by the on-shell process (1S)→γA0 with A0→χχ, or by the off-shell process (1S)→γχχ. Utilizing a data sample of 157.3×106 (2S) decays, we find no evidence for a signal. We set limits on the branching fractions of such processes in the mass ranges MA0<8.97 GeV/c2 and Mχ<4.44 GeV/c2. We then use the limits on the off-shell process to set competitive limits on WIMP-nucleon scattering in the WIMP mass range below 5 GeV/c2. ? 2019 authors. Published by the American Physical Society.
Subjects
Galaxies; Particle beams; Belle experiments; Branching fractions; Dark matter; Data sample; Final state; Higgs boson; Missing energy; Single photons; Bosons
Type
journal article