Photoproduction has been used at colliders for decades in order to study hadronic properties of matter. The energy and luminosity of recent and future colliders allow probing also the electroweak sector through photon-photon and photon-proton interactions. At the HERA electron-proton collider, studies of the W boson production provide a stringent test of the Standard Model. At the LHC, photoproduction has to be separated from the overwhelming background of partonic interactions. A powerful ‘tagging’ technique can be introduced by adding special detectors placed far from the interaction point to detect forward scattered protons, usually present in photon-mediated processes. The HECTOR software package was written in order to provide accurate simulation of forward protons trajectories in the LHC beam-lines. These tools have been used in order to study the photoproduction of top quarks via flavor-changing neutral currents. This process is practically absent in the Standard Model, while it appears in some of its extensions. Detection of such a process would thus be an evidence for the existence of physics beyond the Standard Model.

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

University, Diss., 2004--München.

Universiẗat, Diss., 2004--München.

Universiẗat, Diss., 2001--München.

University, Diss., 2001--München.

University, Diss., 2000--Freiburg (Breisgau). / Parallelt.: Measurement of single w production and triple gauge boson couplings in e+e- collisions at s=161-189 GeV. Text. engl.

Techn. Hochsch., Diss., 2000--Aachen. / Gedr. Ausg. im Physikalischen Inst., Aachen.

University, Diss., 2002--Heidelberg.

A measurement of the electron charge asymmetry in p+→W production in association with jets at sqrt{s}=7 TeV is presented. The dataset corresponds to an integrated luminosity of L=5fb^-1 recorded by the CMS detector in proton-proton collisions at the LHC. The sample represents a large increase in statistical precision with respect to previous CMS results and describes a first study of charge asymmetry measured in p+p→W+1 jet events. Full comparisons to previous results and theoretical predictions are provided and recommendations for extending the analysis to produce valuable input for future PDF models are made.