First indications of the existence of a 38 MeV light scalar boson

Understand

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.