R value measurements for e+e−e+e− annihilation at 2.60, 3.07 and 3.65 GeV

Using a data sample with a total integrated luminosity of 10.0 pb−1 collected at center-of-mass energies of 2.6, 3.07 and 3.65 GeV with BESII, cross sections for e+e−e+e− annihilation into hadronic final states (R   values) are measured with statistical errors that are smaller than 1%, and systematic errors that are about 3.5%3.5%. The running strong interaction coupling constants αs(3)(s) and αs(5)(MZ2) are determined from the R values.