Thesis

Exploring the Hidden Sector of Particle Physics at the SHiP experiment

• Call:

  IDPASC Portugal - PHD Programme 2019

• Academic Year:

  2019 / 2020

• Domain:

  Experimental Particle Physics

• Supervisor:

  Celso Franco

• Co-Supervisor:

  Nuno Leonardo

• Institution:

  Instituto Superior Técnico

• Host Institution:

  Laboratório de Instrumentação e Física Experimental de Partículas

• Abstract:

  The discovery of the Higgs boson at LHC in 2012 made the Standard Model of elementary particles complete. Still, several well-established observational phenomena - neutrino masses and oscillations, dark matter, and baryon asymmetry of the Universe - cannot be explained with known particles alone and clearly indicate that New Physics should exist. The fact that no definitive evidence of new particles have been found so far suggests that they are either heavier than the reach of the present days accelerators or interact very weakly. The SHiP experiment is designed to search for extremely feebly interacting, relatively light and long lived particles, at the intensity frontier. The experiment can also probe the existence of Light Dark Matter through the observation of its scattering on electrons and nuclei in its neutrino detector material. In the region from a few MeV/c^2 to 200 MeV/c^2 the SHiP sensitivity reaches below the limit which gives the correct relic abundance of dark matter. SHiP is being proposed as a discovery experiment but it also includes a rich program of tau neutrino physics and measurements on neutrino-induced charm production. The plan of work is to develop the simulation and reconstruction software of the SHiP experiment with the goal of studying the production and direct detection of Heavy Neutral Leptons (HNLs). These leptons are regarded as the right-handed partners of the standard model neutrinos and, if found in the phase-space region (uniquely) covered by SHiP, the HNLs can provide a natural explanation for dark matter, neutrino masses and baryonic asymmetry of the Universe. The selected student will also perform a detailed study of possible background sources, mimicking HNL decays, with a main focus on the neutrino induced backgrounds. Machine learning algorithms will be used to suppress the residual backgrounds in the spectrometer part dedicated to the Hidden Sector Physics. The student will be integrated as a member of the SHiP Collaboration and trips to CERN are expected. Some trips between Lisboa and Coimbra are also foreseen: the group in Coimbra is a candidate to build a precise timing detector whose properties need to be defined from the HNL simulations.