Theoretical implications of the resonance anomalies in thee+−e−system

Abstract

The phenomenological properties of the recent resonance anomalies at 3.1 GeV and 3.7 GeV in $e^{+}-e^{-}$ systems are confronted in a fairly systematic way with models presently known to us. These include charm-related models, neutral-intermediate-boson-type hypotheses, gauge-related models, and exotic suggestions that the resonant states may have abnormal $C$ parity or that the electromagnetic current has a color triplet piece. We conclude that none of the schemes proposed represents a really satisfactory interpretation of the data.