Measurement of the Charge Asymmetry in WH($\tau\tau$) Events in pp Collisions at 13 TeV at the LHC

The discovery of the Higgs boson in 2012 completed the particle content of the Standard Model (SM) and enabled detailed studies of its properties. While couplings to gauge bosons and third-generation fermions are well established, the coupling to charm quarks remains largely unconstrained. Direct searches for $\mathrm{H}\to\mathrm{cc}$ decays face severe challenges from QCD backgrounds and jet flavor identification. This thesis presents a complementary, indirect approach based on the measurement of the charge asymmetry in associated WH production, which is sensitive to the charm Yukawa coupling.

The analysis is performed using the full Run 2 dataset of the CMS experiment at the LHC, corresponding to an integrated luminosity of $138~\mathrm{fb}^{-1}$.
Since the end of the Run 2 the data have been re-analyzed with improved and consistent simulation, detector alignments and calibrations throughout the data-taking years, by the CMS Collaboration.
Events are selected in final states where the Higgs boson decays to a pair of $\tau$ leptons and the accompanying W boson decays to an electron or muon and a corresponding neutrino. Multiple $\tau\tau$ final states are reconstructed, and advanced analysis techniques are employed to enhance the sensitivity of the analysis. ... mehrBackgrounds from jets misidentified as leptons are estimated with a data-driven $\ff$ method, while genuine multi-lepton backgrounds are modeled with simulation. A neural network classifier is trained to distinguish signal from background and to provide event categorization, improving statistical precision and control over systematic uncertainties.

This work presents the first measurement of the WH charge asymmetry in $\mathrm{H}\to \tau\tau$ decays, along with measurements of the WH, $\mathrm{W^{+}H}$, and $\mathrm{W^{-}H}$ production cross sections. These measurements contribute to the global program of precision Higgs boson measurements, which aim to test the SM and probe for possible signs of physics beyond the SM.