Neutrino oscillations have provided the first observation of physics beyond the standard model, enhancing the interest on the detection of neutrinos from different sources. While traditionally neutrino apparatus are based on large mass technologies, the GanESS project proposes to use small detectors to observe neutrino interactions with the whole nucleus, a process known as coherent elastic neutrino- nucleus scattering. This process, predicted more than 40 years ago, produces ultra-low energy depositions in the detector requiring a technology capable to see such faint signals.

In addition, the fact that neutrinos have mass has opened new question about their nature. In particular, Majorana neutrinos, identical to their own anti-particles, could be the key to explain the asymmetry of matter/anti-matter in the universe.

In this talk I will show how high pressure xenon TPCs are the ideal tool to detect and answer these questions about neutrinos and I describe the GanESS and the NEXT projects.