Abstract
The large rate of the J/ψ+η c production observed by the Belle Collaboration has posed a serious challenge to our understanding of quarkonium. We examine a scenario in which there exists a light scalar boson around 5 GeV, with an enhanced coupling solely to the charm quark. Such a scenario would explain the Belle anomaly. It also predicts a significant increase in J/ψ plus open charm pair production. An immediate test for the scalar boson is to look for a peak around 5 GeV in the recoil mass spectrum J/ψ, because the scalar boson can also be produced in association with the J/ψ. Finally, we also point out that the process e + e - →Hγis sizable for observation. © 2004 The American Physical Society.