A Measurement Of The W Pair Production Cross Section And Derived Mass At Threshold In Electron Positron Collisions

A measurement of the pair production cross section for W bosons has been made, at energies ranging from the nominal threshold energy, 161 GeV, to 202 GeV. Additionally, the mass of the W boson is derived, using the sensitive dependence of the pair production cross section to the W boson mass at the threshold for pair production. Between 1996 and 1999, the ALEPH detector collected a total integrated luminosity of 400 inverse picobarns at LEP2 energies. Analysis of this data yields W pair production cross sections and a W boson mass consistent with the values predicted by the Standard Model. The cross sections are given as effective CC03 cross sections, where the contributions from diagrams not involving two resonant W bosons have been subtracted.