A measurement of the W boson mass using large rapidity electrons

Abstract

We present a measurement of the W boson mass using data collected by the DØ experiment at the Fermilab Tevatron during 1994–1995. We identify W bosons by their decays to eν final states where the electron is detected in a forward calorimeter. We extract the W boson mass M_W by fitting the transverse mass and transverse electron and neutrino momentum spectra from a sample of 11,089 W→eν decay candidates. We use a sample of 1,687 dielectron events, mostly due to Z→ee decays, to constrain our model of the detector response. Using the forward calorimeter data, we measure M_W=80.691±0.227 GeV. Combining the forward calorimeter measurements with our previously published central calorimeter results, we obtain M_W=80.482±0.091 GeV.