Thesis

Probing the CP nature of the Higgs coupling to top quarks with the ATLAS experiment at the LHC

• Call:

  IDPASC Portugal - PHD Programme 2016

• Academic Year:

  2016 / 2017

• Domain:

  Experimental Particle Physics

• Supervisor:

  Ricardo Gonçalo

• Co-Supervisor:

  Antonio Onofre

• Institution:

  Universidade do Minho

• Host Institution:

  Laboratório de Instrumentação e Física Experimental de Partículas

• Abstract:

  The CP nature of the Higgs boson couplings to top quarks is addressed in this PhD thesis proposal. Events from the associated production of top quarks with Higgs bosons (ttH associated production) are searched for in proton-proton collisions at a centre-of-mass energy of 13 TeV at the Run 2 of the LHC. A dedicated analysis for ttH dileptonic events with final states with two oppositely charged leptons and at least four jets from the decays of the top quarks and Higgs boson (H->bb) is expected to be developped. Data collected by the ATLAS experiment at CERN is expected to be analysed. Full kinematical event reconstruction is performed using a specific fitter which will be able to reconstructed the four momenta of the undetected neutrinos. Following reconstruction, search for specific angular distributions that may discriminate between the dominant background (ttbb) and the signal are expected to be studied. Their impact on the signal sensitivity is to be quantified using ATLAS data collected at the Run 2. Pure scalar (h = H) and pseudo-scalar (h = A) Higgs boson signal events will be generated with dedicated Monte Carlo generators for the LHC, as well as scenarios involving mixtures between scalar and pseudoscalar contributions to the vertex.