Physics Reach of a Reactor CEvNS Liquid Argon SBC

A successful CEvNS measurement requires a large neutrino flux, low backgrounds, and a detector sensitive to low energy nuclear recoils. Nuclear reactors offer a free flux of ~MeV neutrinos and an off-reactor data set allows for subtraction of non-reactor backgrounds. The Scintillating Bubble Chamber (SBC) collaboration is currently constructing a 10-kg liquid argon scintillating bubble chamber at Fermilab. The detector has the potential to be sensitive to 100-eV nuclear recoils while remaining highly insensitive to electron recoil backgrounds. In addition, silicon photomultipliers (SiPM) can measure scintillation light to maximize background rejection for nuclear recoils. Nearly mono-energetic photoneutron sources can calibrate the detector for nuclear recoils below 8 keV and gamma sources can use Thomson scattering to probe the nucleation efficiency function near the targeted 100-eV threshold. This talk presents a physics reach analysis of such a detector for reactor CEvNS experiments, including sensitivities to: the weak mixing angle, neutrino magnetic moment, and a light Z gauge boson mediator. World leading sensitivities could be achieved with a 1 year exposure of a 100-eV detector 3 m from a 1 MW_th research reactor.