Beyond the Standard Model.. and how to get there

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In the 60s, theoretical physicists had written the rule-book for the game of particle interactions: the "Standard Model of Particle Physics". This model has been very solid for more than 50 years now, providing precise theoretical predictions which have stood experimental test countless times. Yet, a particle called the "neutrino" breaks the rules, and its criminal behavior could help explain why the Universe didn't simply disappear in a flash of light just after the Big Bang. Additionally, astronomers have observed a new type of matter, dark matter, tying galaxies together. Since we think that everything in the Universe is made of particles, dark matter particles should exist, but have eluded experimental physicists for at least 30 years. These "criminals" tell us that what we once thought was the rule-book of the Universe is actually just a chapter in a much bigger tome, unfortunately much harder to read.For this fellowship, I propose a 3-fold program that will open pathways to explore physics Beyond the Standard Model via the creative use of Liquid Argon Time Projection Chambers (LArTPCs) the cutting-edge technology that I spent the last seven years of my research developing and performing world-leading measurements with.LArTPCs have been chosen by the international neutrino community to construct the Deep Underground Neutrino Experiment (DUNE), the next flagship experiment in the field. DUNE, will go live in the late 2020s, is set to identify the neutrino's role at the beginning of the Universe via the measurement of neutrino oscillations: the appearance of neutrinos of the electron type in a beam of neutrinos of the muon type. This Beyond Standard Model measurement will reach the required sensitivity and be successful only if we characterize how electron neutrinos interact with the argon beforehand. My first objective is measuring for the first time the comprehensive set of quantities needed for this characterization: electron neutrino cross sections in argon. I will perform this search using the biggest sample of electron neutrino interactions ever recorded on argon -- a dataset from the MicroBooNE experiment, a smaller LArTPC on the surface. MicroBooNE's constant exposure to a heavy rain of cosmic muons produced in the atmosphere represents a key background which I will have to study and remove to identify electron neutrinos; but it has the potential to become an unexpected treasure. Indeed, the second objective of my fellowship is to pivot my first analyses and scan the muon data for a signature of the long-sought-after dark matter particle. I will perform this search with a method developed for my PhD thesis; and its application to dark matter searches has never been attempted before. If evidence of the elusive dark matter particle is found in the muon data, the impact would be transformational. The third objective of my strategy tackles Beyond Standard Model physics from an technological perspective, pushing the boundaries of the LArTPC. Multi-kiloton underground neutrino detectors like DUNE provide a unique opportunities to register extremely rare events predicted only by theories more fundamental than the Standard Model rule-book. Combining innovative pixel technology with state of the art research on amorphous selenium and graphene, this fellowship will allow me to develop a sensor that optimizes the LArTPC performances for these extremely rare events.My proposed research program incorporates high-impact and novel analyses with an ambitious but potentially transformative technology development. This work outlines a clear path to ensure DUNE's success in its Beyond Standard Model program, while describing innovative dark matter searches to be performed on already available datasets. Since definitive experimental proof of what lies beyond has been extremely elusive, the impact of any Beyond Standard Model discovery would transform our understanding of Nature.