DarkSHunt · Hunting sub-GeV Dark Sectors

There is incontrovertible evidence that the Standard Model is not the ultimate theory of particles and interactions: it cannot explain neutrino masses, dark matter, our own existence (i.e. the Universe baryon asymmetry). A New Standard Theory must exist.The key question is: what is the new physics scale? In the past decades, a formidable effort took place to explore the TeV scale, culminating in the LHC experiments, but no evidence of new physics has been found.A change of paradigm may be required. New physics at low masses, the so-called dark sectors, offers a viable alternative. Their theoretical study and experimental searches are blooming.The next 5 years offer a unique window of opportunity. New experiments will be taking data opening the possibility to search for dark sectors with unprecedented sensitivity and novel strategies: from the SBN programme, to ProtoDUNE, NA64, KM3Net, complemented by beam-dump, collider, sub-GeV dark matter, high energy neutrinos and gravitational wave searches. DarkSHunt ultimate aim is to exploit this opportunity to uncover hints (or evidence) of Dark Sectors, collaborating directly with leading experimentalists to perform dedicated analysis. It will focus on the most promising experimental strategies to search for heavy neutral leptons, dark photons, sub-GeV dark matter. It will adopt a phenomenological approach, necessary to combine information from diverse experiments, and will complement it with theoretical and astroparticle/cosmological considerations. It will focus specifically on rich (i.e. non-minimal) dark sectors at the GeV scale. Thanks to their multiple particles and interactions, they have strong theoretical motivation, can explain the 2023 discovery of nanoHertz gravitational waves and have nearly-unexplored phenomenology.If DarkSHunt achieves its ultimate goal, it would have a groundbreaking impact on our understanding of fundamental particles and interactions, paving the way to new research directions.