Wideband Direct Detection Constraints on Hidden Photon Dark Matter with the QUALIPHIDE Experiment.

We report direction detection constraints on the presence of hidden photon dark matter with masses between 20-30 µeV c^{-2}, using a cryogenic emitter-receiver-amplifier spectroscopy setup designed as the first iteration of QUALIPHIDE (quantum limited photons in the dark experiment). A metallic dish sources conversion photons, from hidden photon kinetic mixing, onto a horn antenna which is coupled to a C band kinetic inductance traveling wave parametric amplifier, providing for near quantum-limited noise performance. We demonstrate a first probing of the kinetic mixing parameter χ to the 10^{-12} level for the majority of hidden photon masses in this region. These results not only represent stringent constraints on new dark matter parameter space, but are also the first demonstrated use of wideband quantum-limited amplification for astroparticle applications.

Development of Superconducting On-chip Fourier Transform Spectrometers.

Superconducting On-chip Fourier Transform Spectrometers (SOFTS) are broadband, ultra-compact and electronic interferometers. SOFTS will enable kilo-pixel spectro-imaging focal planes, enhancing sub-millimeter astrophysics and cosmology. Particular applications include cluster astrophysics, cosmic microwave background (CMB) science, and line intensity mapping. This article details the development, design and bench-marking of radio frequency (RF) on-chip architecture of SOFTS for Ka and W-bands.

HOLMES: The electron capture decay of [Formula: see text]Ho to measure the electron neutrino mass with sub-eV sensitivity.

The European Research Council has recently funded HOLMES, a new experiment to directly measure the neutrino mass. HOLMES will perform a calorimetric measurement of the energy released in the decay of [Formula: see text]Ho. The calorimetric measurement eliminates systematic uncertainties arising from the use of external beta sources, as in experiments with beta spectrometers. This measurement was proposed in 1982 by A. De Rujula and M. Lusignoli, but only recently the detector technological progress allowed to design a sensitive experiment. HOLMES will deploy a large array of low temperature microcalorimeters with implanted [Formula: see text]Ho nuclei. The resulting mass sensitivity will be as low as 0.4 eV. HOLMES will be an important step forward in the direct neutrino mass measurement with a calorimetric approach as an alternative to spectrometry. It will also establish the potential of this approach to extend the sensitivity down to 0.1 eV. We outline here the project with its technical challenges and perspectives.