Aspects of very massive dark matter

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Scientific background: The requirement of thermal creation of dark matter in the early universe relates the mass of dark matter (DM) particles with the DM coupling strength to baryonic matter. Outside of resonance regions (resonant enhancement of DM creation appears e.g. for DM masses near 63 GeV for Higgs portal dark matter), the creation of heavier DM particles requires higher coupling strength to baryonic matter. We find that the coupling constant for bosonic Higgs portal dark matter will become non-perturbative in the several TeV mass range (please see full proposal for details). Increasing coupling strength with increasing mass for thermal DM creation is a generic phenomenon. However, hidden sectors with non-perturbative coupling strength to baryonic matter still provide viable DM models due to suppression of recoil and annihilation cross sections with mass. On the other hand, currently starting direct search experiments like DEAP-3600 and XENON1T, as well as the upcoming LZ experiment, will be sensitive to the multi-TeV dark matter mass range. Therefore it is very important to develop theoretical techniques to make predictions for DM annihilation and nuclear recoil cross sections also in the non-perturbative regime. Objectives of the proposed research project: Our objective is to develop non-perturbative techniques for the high mass dark matter sector, to compare experimental observations with models in the multi-TeV mass range. Our aim is to make theoretical predictions for annihilation cross sections (important for balance equations for thermal creation and for indirect dark matter search), for nuclear recoil cross sections (important for direct search experiments which will be sensitive to the high mass range), and for production cross sections at the LHC and at lepton colliders. Implications and ramifications of the research project: The start of the exploration of the multi-TeV dark matter mass range with currently starting or upcoming direct search experiments is extremely exciting and makes this research project very timely to offer support from the theory side, and to connect the findings of the experiments with dark matter models. We anticipate that connecting the findings from the direct search experiments with theoretical models will be the main thrust and impact of the project. However, we are also hopeful that the need to address non-perturbative models from a dark matter side, as a complementary motivation to hadronic physics, will feed back into an improved general understanding of non-perturbative field theories and will also help to improve our understanding of hadronic physics. Canadians have a keen interest in research at the frontier of knowledge and take great pride in Canada's world-class contributions through the support of the facilities and experiments at national labs. Theoretical analysis of dark matter models provides important support for these endeavors.