Thesis

Rare Higgs decays and couplings to quarks

• Call:

  PT-CERN Call 2021/1

• Academic Year:

  2021

• Domain:

  Astroparticle Physics

• Supervisor:

  Nuno Leonardo

• Co-Supervisor:

  Sandro Fonseca de Souza

• Institution:

  Instituto Superior Técnico (Universidade de Lisboa)

• Host Institution:

  Laboratório de Instrumentação e Física Experimental de Partículas

• Abstract:

  After the discovery of Higgs boson at LHC in 2012 the main focus of the scientists is to probe the decays of this special particle to various other Standard Model particles. The Higgs Mechanism predicts the role of this scalar boson in generating mass of the fundamental particles. Therefore how Higgs boson interacts or couples to other particles is an extremely important question to understand the origin and existence of our universe. Higgs coupling to gauge bosons was discovered at LHC. In 2018 CMS and ATLAS detectors discovered Higgs couplings to heavy fermions such as top and bottom quarks. The recent studies using the data set from CMS detector shows the evidence of muonic decay of Higgs boson. Hence the next step is to probe Higgs decay to second generation quarks using the data from CMS during LHC Run 3. It is very difficult to obtain the traces of this rare decay. Therefore to carry out the investigation of Higgs coupling to light quarks, we can use Higgs decay to a quarkonium state and a photon. The analysis of this decay channel will help to identify the nature of Higgs coupling to other SM particles. Therefore we will be able to probe the properties of Higgs boson. This study will help to decide whether this particle belongs to the Standard Model or first particle beyond the Standard Model.