High Energy Physics Seminar
The identification of dark matter (DM) is a central question for high-energy physics and one of the strongest motivations for physics beyond the standard model. In light of the lack of evidence for supersymmetry at the LHC, theoretical models for particle DM have veered towards ideas like a ‘dark sector', where there may be many different light DM particles, including some that mediate the interaction with normal matter. All of these light DM candidates would deposit meV-scale to eV-scale energies in an earth-bound detector. The challenge for experiments is to develop detectors that can measure the sub-eV energy deposits produced by such potential DM interactions.
In this talk, I will discuss the roadmap for detector R&D down to meV energy thresholds for background-free, gram-day exposures, in the context of the experiments I am currently involved in. These include a broadband axion search in the 0.1-10 THz energy range, and the expansion of phonon-mediated detectors to sub-eV thresholds beyond my current SuperCDMS HVeV program. This work also has broad synergies with understanding qubit decoherence times for superconducting quantum computing, which is the current limitation on complexity of modern quantum computers. I will touch on recent results which relate efficient phonon detection for radiation detection to qubit responses to external radioactivity and near-term plans at Fermilab to continue these studies in NEXUS and QUIET, our low-background test facilities. The R&D for radiation-hardened qubit architectures goes hand in hand with massively multiplexed phonon sensors, and I will discuss how both dark matter and quantum science can be studies in the same experimental infrastructure.