Total Cross Section for Hadron Production by Electron-Positron Annihilation between 2.4 and 5.0 GeV Center-of-Mass Energy

The total cross section for hadron production by $e^{+}{e}^{-}$ annihilation has been measured at center-of-mass energies between 2.4 and 5.0 GeV. Aside from the very narrow resonances $\psi \mathrm{}\left(3105\right)\mathrm{}$ and $\psi \mathrm{}\left(3695\right)\mathrm{}$, the cross section varies between 32 and 17 nb over this region with structure in the vicinity of 4.1 GeV.