The neutrino discovery by Reines & Cowan paved the technical ground behind the establishment of much of today’s neutrino detection. Large instrumented volumes can and have been achieved via a key (implicit) principle: detector transparency. Much of that technology has yielded historical success since the 50s, including several Nobel prizes. The discovery of the Neutrino Oscillation phenomenon is a beautiful example of solving the long-standing “Solar” and “Atmospheric” anomalies by SNO and SuperKamiokande — along with many other experiments. Despite the remarkable success, much of such a “transparent technology” is known to suffer from some key limitations even after 70 years of maturity towards perfection. The challenge continues to endow detectors with powerful active background rejection while allowing large-volume articulation. Indeed, poor particle identification is a long-standing issue, only alleviated by adding an external shield (active or passive), which implies a major overburden to the underground laboratories. In this seminar, I shall present for the first time a new technology, under intense R&D, called “LiquidO”, relying heavily on the detection of medium opacity for the first time. The effort is led by the LiquidO collaboration (20 institutions over 11 countries). We shall compare LiquidO to its transparent counterpart for maximal appreciation. While not perfect, LiquidO seems to one able to offer several detection features that might lead to breakthrough potential in the context of both neutrino and rare decay physics. This will be briefly highlighted too.

The first international release of the LiquidO technology and project (https://liquido.ijclab.in2p3.fr), led by the homonymous LiquidO scientific consortium.