First indications of the existence of a 38 MeV light scalar boson
  We present evidence for the existence of a light scalar particle that most
probably couples exclusively to gluons and quarks. Theoretical and
phenomenological arguments are presented to support the existence of a light
scalar boson for confinement and quark-pair creation. Previously observed
interference effects allow to set a narrow window for the scalar's mass and
also for its flavor-mass-dependent coupling to quarks. Here, in order to find a
direct signal indicating its production, we study published BABAR data on
leptonic bottomonium decays. We observe a clear excess signal in the
invariant-mass projections of electron-positron and muon-antimuon, which may be
due to the emission of a so far unobserved scalar particle with a mass of about
38 MeV. In the process of our analysis, we also find an indication of the
existence of a bottomonium-like hybrid state at about 10.061 GeV. Further
signals might be interpreted as replicas of the light scalar, with masses
roughly two and three times as large.
