Dark biportals at direct detection

We present a study of the constraining power low-threshold, high-resolution direct-detection experiments for biportal simplified dark matter model. In scenario we consider here, and Standard Model particles interact through two vector mediators---one light one heavy with respect to momentum transfer in experiment. Interference effects at level scattering amplitudes can lead novel marked shape features differential recoil spectra, which are best exploited by high-resolution, low-threshold experiments. identify region parameter space our model where such dominant show that composite-target large atomic mass differences ideal explore these scenarios. develop profile likelihood approach analyze presently available future data. Using published results CRESST-III experiment projections sensitivities COSINUS experiment, constrain model, thereby showing potential an analysis class models exhibit nonstandard spectra.