Measurement of the Q² dependence of the Charged and Neutral Current Cross Sections in e^(pm)p Scattering at HERA

The $Q^{2}$ dependence and the total cross sections for charged and neutral current processes are measured in $e^{\pm}p$ reactions for transverse momenta of the outgoing lepton larger than 25 GeV. Comparable size of cross sections for the neutral current process and for the weak charged current process are observed above $Q^2~\approx~5000$ GeV$^2$. Using the shape and magnitude of the charged current cross section we determine a propagator mass of $m_{W} = 84\ ^{+10}_{-7}$ GeV.