An Improved W Boson Mass Measurement using the Collider Detector at Fermilab

Abstract

The mass of the $W$ boson is one of the most important parameters in the Standard Model. A precise measurement of the $W$ boson mass, together with a precise measurement of the top quark mass, can constrain the mass of the undiscovered Higgs boson within the Standard Model framework or give a hint for physics beyond the Standard Model. This dissertation describes a measurement of the $W$ boson mass through its decay into a muon and a neutrino using $\approx$ 2.2 fb$^{-1}$ of $\sqrt{s} = 1.96$ TeV $p\bar{p}$ data taken with the CDF II detector at Fermilab. We measure the $W$ boson mass to be ($80.374 \pm 0.015_{\rm stat.} \pm 0.016_{\rm syst.}$) GeV/c$^2$. This result, when combined with the $W$ mass measurement in the electron channel, leads to the single most precise $m_W$ value and greatly constrains the possible mass range of the undiscovered Higgs boson.