Thesis

Testing the WIMP paradigm to the limit

• Call:

  PT-CERN Call 2021/2

• Academic Year:

  2021

• Domain:

  Astroparticle Physics

• Supervisor:

  Rui Santos

• Co-Supervisor:

  Milada Margarete Mühlleitner

• Institution:

  FCUL (Universidade de Lisboa)

• Host Institution:

  CFTC - Centro de Física Teórica e Computacional

• Abstract:

  The search for Dark Matter (DM) is one of the main goals of present high energy physics and astrophysics experiments. Many direct and indirect detection experiments together with searches at the Large Hadron Collider (LHC) have so far provided only bounds on the DM mass and couplings. DM candidates, which may be bosons or fermions, arise in many extensions of the Standard Model (SM) in a wide mass range. In recent years there has a been a shift from the so-called Weakly Interacting Massive Particle (WIMP) paradigm to the very low mass region of axions and other very light particles. However, many of the present and future planned experiments for direct and indirect searches, such as e.g., the XENONnT [1], DARWIN [2] and SWGO [3] experiments, together with the high luminosity stage of the LHC and future colliders, will still be focused on the WIMP mass region. Furthermore, many of the simplest models one can build still allow for a WIMP candidate. Hence, even if no DM signal was found yet, we should certainly not rush into declaring the death of the WIMP with still so much to explore. The objective of this work is to test the WIMP paradigm to the limit - will future experiments finally gives us a WIMP, or will we have to find a new paradigm? Higher order corrections can change the limits obtained from the experiments for DM masses and couplings within each model. In some cases, higher order corrections have a dramatic effect on the interpretation of the results. More importantly, it is possible that corrections to similar processes can have a much higher impact in say indirect detection than in direct detection. Therefore, only corrections to all processes involving DM in the three probing modes: direct, indirect and collider, can give us a clear idea of their importance. We expect to give a significant contribution towards answering if we are definitely entering a very light/heavy era for DM or if the WIMP is just in a moribund condition until we finally detect it.