$W$ boson production in ultrarelativistic heavy-ion collisions at the CERN LHC

Ultrarelativistic heavy-ion collisions at the CERN Large Hadron Collider (LHC) are capable of producing a medium of deconfined quarks and gluons. This phase of nuclear matter is called a Quark-Gluon Plasma (QGP) and is believed to have been present during the first microseconds following the Big Bang. $\Wboson$ bosons are a unique probe in a QGP since they do not carry color charge and thus do not interact with a strongly-coupled medium. Furthermore, the kinematics of $\Wboson$ bosons are sensitive to the Bjorken momentum fraction $x$ of partons within nucleons, and therefore $\Wboson$ bosons may also be used to constrain parton distribution functions and to detect the presence of nuclear effects. This thesis presents the measurement of $\Wboson$ boson production in the dense nuclear environment created in $\PbPb$ collisions at a per nucleon pair center-of-mass energy $\sqrt{s_{\mathrm{NN}}}=2.76\TeV$. The data for this measurement were collected with the ATLAS detector in 2011 and correspond to an integrated luminosity $\int \mathrm{L}\mathrm{dt} = 0.14~\mathrm{nb}^{-1}$. The production of $\Wboson$ bosons is detected using the $\wmunu$ decay channel, resulting in fiducial yields of 5487 $\pm96 \stat$ $\pm86 \syst$ $\wmunup$ events and 5262 $\pm95 \stat$ $\pm83 \syst$ $\wmunum$ events. These results are combined with yields from the corresponding electron channel $\wenu$, and the combined measurement is used to construct the differential production yields and lepton charge asymmetry as a function of lepton absolute pseudorapidity. The integrated production yields and charge ratio as a function of the mean number of binary nucleon-nucleon collisions $\mNpart$ are also presented. The results are compared to predictions based on next-to-leading order QCD calculations. These observables can aid in better understanding nucleon structure within a heavy nucleus as well as provide insight into the mechanism of jet energy loss in a QGP.