Séminaire post-doctorants: Pierre Jamet (Theory) & Birgit Zatschler (Neutrinos) (1/3)

Tuesday 16 Jan 2024, 10:00 → 11:00 Europe/Paris

Grand Amphithéâtre (LPSC)

Pierre Jamet: Classical analogs of quantum mechanics and wave particle duality - blackboard talk

Wave-particle duality has been a central idea for the development of quantum mechanics. Initially introduced by Louis de Broglie in his Ph.D. thesis of 1924, it allowed him to sketch a new theory of the microscopic world: wave mechanics. However, this mechanical description and its more rigorous form, the double solution theory, were soon abandoned because of their apparent complexity, in favor of the modern quantum formalism and the associated Copenhagen interpretation. Interest in these questions was renewed in the last two decades, as experiments were performed on macroscopic systems that could be seen as analogs of quantum mechanics. Yves Couder’s experiments of 2005 were integral in this, showing that it was indeed possible to reproduce a form of wave-particle duality at the macroscopic scale as well as the associated quantum phenomena.

This talk will be largely based on my Ph.D. thesis, in which I attempted to reintroduce the aforementioned ideas in order to construct a classical and mechanical theory of wave-particle duality as an analog of quantum mechanics. I will choose to focus more on the context of my work, both scientific and philosophical. This should be an opportunity to discuss several less well-known aspects of the historical development of quantum mechanics, shedding light on some of the quantum weirdness.

Birgit Zatschler: Searching for Dark Matter with the SuperCDMS SNOLAB Experiment

Various forms of astrophysical evidence indicate the existence of Dark Matter (DM) which is predicted to account for about 85% of the matter in the universe. Our solar system moves through the hypothesized DM halo in our galaxy and many experiments pursuing different detection approaches are aiming to observe the resulting DM particle flux.

Among them, SuperCDMS is a direct detection DM experiment presently being constructed at the SNOLAB underground facility in Sudbury, Canada. It will make use of cryogenically cooled Germanium and Silicon crystals to measure ionization and phonon signals, allowing the distinction between electron recoils and nuclear recoils. While the former is typically induced by background events, the latter can be caused by DM particles. With that recoil discrimination ability, a separation between background and signal is possible which helps to improve the sensitivity of the experiment. Background events can be caused by various sources such as cosmogenic radiation and activation of materials while they are transported above ground. Additionally, intrinsic radioactive impurities in the materials surrounding the detectors contribute to the background. It is crucial to understand the background composition of the measured data to observe a potential DM signal. For every component the time above ground is monitored and each material used to build the experiment is assayed to determine its radioactive impurity content. Using this information, dedicated Monte Carlo simulations are performed to model the experiment’s background.

This talk will give an introduction to Dark Matter and its evidence, provide an overview of the SuperCDMS experiment and its current status as well as explain the challenges of simulating background sources of the experiment with high statistics.

DM_SuperCDMS_Birgit_Zatschler.pdf