Exploring the Sensitivity to Non-Standard Neutrino Interactions of NaI and Cryogenic CsI Detectors at the Spallation Neutron Source

After the first observation of coherent elastic neutrino-nucleus scattering (CE$\nu$NS) by the COHERENT collaboration, many efforts are being made to improve the measurement of this process, making it possible to constrain new physics in the neutrino sector. In this paper, we study the sensitivity to non-standard interactions (NSIs) and generalized neutrino interactions (GNIs) of two experimental setups at the Spallation Neutron Source at Oak Ridge National Laboratory: a NaI detector with characteristics similar to the one that is currently being deployed there, and a cryogenic CsI detector proposed at the same facility. We show that a combined analysis of the data from these detectors, whose target nuclei have significantly different proton-to-neutron ratios, could help to partially break the parameter degeneracies arising from the interference between the Standard Model and NSI contributions to the CE$\nu$NS cross section, as well as between different NSI parameters. By contrast, only a slight improvement over the current CsI constraints is expected for parameters that do not interfere with the SM contribution.