Speaker
Description
The recent observation of coherent neutrino-nucleus elastic scattering, or CEvNS for short, provides a novel window to probe standard and beyond standard physics in the neutrino sector. A key feature of nuclear interactions is when the momentum transferred to the nucleus is relatively small, near or below the MeV scale, so that the neutrino can coherently scatter off the whole nucleus instead of distinguishing its individual nucleons. The coherence of the interaction results in sensitivity to the square of the total weak charge of the nucleus, which could enhance the coherent scattering cross-section by a factor of 10-100 when compared to neutrino-nucleon scattering. In addition, new non-standard interactions of neutrinos with matter can be enhanced at low recoil energies if the new interaction is mediated by a light particle. The light mediator can be a new beyond standard model (BSM) particle, such as a B − L gauge boson or a light scalar, but it can also be the photon if the neutrino possesses a magnetic dipole moment. Both possibilities would signal the presence of new BSM physics. Nuclear reactors provide the largest neutrino flux for a facility on Earth. Reactor neutrino energies are compatible with the coherence enhancement (~2-4 MeV), but at the same time, the scattering kinematics drastically limits the transferred energy, especially to a nucleus. The combination of these three aspects: the cross-section enhancement for nuclear interaction for the reactor neutrino energies, the very low energy threshold of available sensor technologies to observe faint depositions, and the most intense neutrino flux on earth, make the proposed framework a unique tool to search for dark sector candidates and new light physics in new regimes.
In addition, nuclear reactors are also a very intense source of photons that can interact with the reactor structure and produce other dark sector candidates (such as axion-like particles, hidden photons, etc.) that can leave the core and be detected by low threshold sensors. Recent studies have shown competitive sensitivities to search for these models at nuclear facilities.
In this talk, we will discuss different models that can be explored with this technique and we will expose the main advantages of these types of searches over existing alternatives. We will also give some of the technical requirements to achieve the expected sensitivity.
