Thesis

Search for the supersymmetric partner of the top quark (stop) at the Large Hadron Collider

• Call:

  IDPASC Portugal - PHD Programme 2016

• Academic Year:

  2016 / 2017

• Domain:

  Experimental Particle Physics

• Supervisor:

  Pedrame Bargassa

• Co-Supervisor:

  Joao Varela

• Institution:

  Instituto Superior Técnico

• Host Institution:

  Laboratório de Instrumentação e Física Experimental de Partículas

• Abstract:

  Supersymmetry (SUSY) presents many attractive features in light of the recent discovery of the Higgs boson at CERN, but also in relation with cosmological observations. It is one of the most active areas of search at the Large Hadron Collider (LHC) of CERN. SUSY partners of quarks (squarks) are among the most accessible SUSY particles at the LHC. For every quark, the mass splitting between pairs of squarks is proportional to the Standard Model (SM) quark mass. Since the top is the heaviest SM quark, the lightest stop may be the lightest squark, thus the most easily observable at LHC. Stop searches are at present among the most exciting searches at the LHC. The proposed search aims at the search for the SUSY partner of the top quark (stop) with the CMS experiment at the LHC. It targets a scenario where the mass difference between the stop & the Lightest SUSY Particle (LSP) is small. The measure of the Cold Dark Matter (CDM) density gives a high preference to such compressed mass spectrum. This search will be led in the “lepton + missing energy + jets” final state, taking advantage of the expertise of the LIP CMS group in the LHC data with this signature. The search will make use of innovative selection approaches such as the multivariate analysis tools, in which our group has experience.