Measuring the inclusive cross section of $\rm e^+e^-$ annihilation into hadrons in the pre-asymptotic energy range

Among the observed variety of the natural phenomena reflected in experimental results, there are just a few physical features offering a view of a given fragment of the mosaic of physical laws in its entirety. One such remarkable fundamental feature is $R$, the ratio of the inclusive cross section of electron–positron annihilation into hadrons to the cross section of muon pair production in the Born approximation. We discuss experiments on measuring the $R(s)$ ratio in the energy range 1.84–3.72 GeV.