Measurement of the total hadronic cross section in $e^{+}{e}^{-}$ annihilation below 10.56 GeV

Using the CLEO III detector, we measure absolute cross sections for $e^{+}{e}^{-}\to \mathrm{\text{hadrons}}$ at seven center-of-mass energies between 6.964 and 10.538 GeV. The values of $R$, the ratio of hadronic and muon pair production cross sections, are determined within 2% total root-mean-square uncertainty.

Figure 1

Visible energy distribution at 9.996 GeV, normalized to center-of-mass energy, when all cuts are applied except the one shown. In this as well as in all other figures, arrows indicate cut values.

Figure 2

The ratio of the $z$ component of the event missing momentum to event visible energy $P_z^{\mathrm{miss}}/E_{\mathrm{vis}}$ at 10.538 GeV.

Figure 3

The ratio of calorimeter energy of charged and neutral particles to $2E_{\mathrm{beam}}$ at 10.538 GeV.

Figure 4

Distribution of the ratio of Fox-Wolfram moments $H_2/H_0$ at 6.964 GeV.

Figure 5

The ratio of the most energetic shower energy to the beam energy at 8.380 GeV.

Figure 6

Charged particle multiplicity distribution at 10.330 GeV.

Figure 7

$k$ distribution of the Monte Carlo continuum sample at 10.538 GeV.

Figure 8

Hadronic event detection efficiency as a function of $k$ at 9.996 GeV.

Figure 9

Net charge distribution of events at 9.996 GeV.

Figure 10

$R$ measurement at 5.0–10.5 GeV c.m. energies. The top figure compares our measurement with other experiments [19]. The bottom plot shows our new results, where two sets of uncertainties represent combined uncorrelated and statistical uncertainties and total uncertainties; the line represents Eq. (2) with our average $\Lambda =0.31\mathrm{GeV}$, and the shaded area indicates the $R$ values corresponding to 1 standard deviation in the uncorrelated systematic uncertainty in $\Lambda$.