SU(4) Explanation of the Narrow Resonances ine+e−Annihilation

The narrow resonances at $M_{\psi }=3.105\mathrm{}$ GeV and $M_{{\psi }^{\prime }}=3.695\mathrm{}$ GeV are assigned, together with the familiar SU(3) nonet of vector mesons, as members of the 1 ⊕ 15 representation of SU(4). This leads to a solution consistent with the observed particle spectrum and accounts for the narrow widths of the $\psi$ and ${\psi }^{\prime }$. The masses of the charmed vector and pseudoscalar mesons are predicted.