Low-energy probes of sterile neutrino transition magnetic moments

Sterile neutrinos with keV-MeV masses and non-zero transition magnetic moments can be probed through low-energy nuclear or electron recoil measurements. Here we determine the sensitivities of current and future searches, showing how they can probe a previously unexplored parameter region. Future coherent elastic neutrino-nucleus scattering (CEνNS) or elastic neutrino-electron scattering (EνES) experiments using a monochromatic 51Cr source can fully probe the region indicated by the recent XENON1T excess.

Supernova Preshock Neutronization Burst as a Probe of Nonstandard Neutrino Interactions

A core-collapse supernova (CCSN) provides a unique astrophysical site for studying neutrino–matter interactions. Prior to the shock-breakout neutrino burst during the collapse of the iron core, a preshock ν e burst arises from the electron capture of nuclei and it is sensitive to the low-energy coherent elastic neutrino–nucleus scattering (CEνNS) which dominates the neutrino opacity. Since the CEνNS depends strongly on nonstandard neutrino interactions (NSIs), which are completely beyond the standard model and yet to be determined, the detection of the preshock burst thus provides a clean way to extract the NSI information. Within the spherically symmetric general-relativistic hydrodynamic simulation for the CCSN, we investigate the NSI effects on the preshock burst. We find that the NSI can maximally enhance the peak luminosity of the preshock burst almost by a factor of three, reaching a value comparable to that of the shock-breakout burst. Future detection of the preshock burst will have critical implications on astrophysics, neutrino physics, and physics beyond the standard model.

Probing neutrino dipole portal at COHERENT experiment

Motivated by the first observation of coherent-elastic neutrino-nucleus scattering at the COHERENT experiment, we confront the neutrino dipole portal giving rise to the transition of the standard model neutrinos to sterile neutrinos with the recently released CENNS 10 data from the liquid argon as well as the CsI data of the COHERENT experiment. Performing a statistical analysis of those data, we show how the transition magnetic moment can be constrained for the range of the sterile neutrino mass between 10 keV and 40 MeV.

Dark matter electromagnetic dipoles: the WIMP expectation

We perform a systematic study of the electric and magnetic dipole moments of dark matter (DM) that are induced at the one-loop level when DM experiences four-fermion interactions with Standard Model (SM) charged fermions. Related to their loop nature these moments can largely depend on the UV completion at the origin of the four-fermion operators. We illustrate this property by considering explicitly two simple ways to generate these operators, from t- or s-channel tree-level exchange. Fixing the strength of these interactions from the DM relic density constraint, we obtain in particular a magnetic moment that, depending on the interaction considered, lies typically between 10−20 to 10−23 ecm or identically vanishes. These non-vanishing values induce, via photon exchange, DM-nucleus scattering cross sections that could be probed by current or near future direct detection experiments.