Deep inelastic $e^{-}p$ scattering has been studied in both the charged current (CC) and neutral current (NC) reactions at momentum transfers squared $Q^2$ above $400{\mathrm{GeV}}^2$ using the ZEUS detector at the HERA $\mathrm{ep}$ collider. The CC and NC total cross sections, the NC to CC cross section ratio, and the differential cross sections $d\sigma /{\mathrm{dQ}}^2$ are presented. From the $Q^2$ dependence of the CC cross section, the mass term in the CC propagator is determined to be $M_W=76\mathrm{}\pm 16\pm 13$ GeV.

• Received 31 March 1995

DOI:https://doi.org/10.1103/PhysRevLett.75.1006