Measuring the Mass of the W Boson with the Last 3.7 fb−1 of Tevatron Data.

Abstract

This thesis presents the results of an analysis of the $3.7\,\textrm{fb}^{-1}$ of Tevatron proton-antiproton data collected with the DZero (D0) Detector at Fermilab during the ``RunIIb34'' period, with the goal of extracting an improved measurement of the $W$ boson mass, which is currently measured to a precision of $\approx 20\,\textrm{MeV}$. The measurement is performed on events with one $W$ boson which decays to an electron and a neutrino. Using a template technique, the mass is measured from three distributions that are correlated with the $W$ boson mass: the transverse electron momentum, $p_T^e$, the transverse $W$ mass, $m_T$, and the neutrino momentum, which appears as missing transverse energy, $\slashed{E}_T$. A test measurement using this technique is successfully performed on a mock dataset generated with a Monte Carlo simulation. In the data, we find unexpected azimuthally dependent inconsistencies between the early and late parts of the data taking period. Implications for the completion of the data measurement are discussed.