Coherent Neutrino detection

Detection of coherent absorption of light by nuclear magnetic moments

Pirelli Labs is continuing a research originally started by Prof. Joseph Weber (Maryland University) in the eighties about the possibility of detecting neutrinos using the quantum coherent properties of a particular crystal. The new method is similar in principle to the well known "Moessbauer effect" in the gamma ray domain.

Weber's work was concerned with the possibility that very weakly interacting particles (such as neutrinos or gravitons) may be scattered by strongly bound scatterers. Nearly perfect single crystals with high Debye temperature have atomic nuclei which are coupled to each other with sufficient strength to permit scattering processes in which nuclei exchange momentum without phonon excitation.

This may lead to unusually large cross sections whose scaling is proportional to N2 (N number of atoms) even when the De Broglie wavelength is small compared to the average distance among adjacent scatterers.

The observation of such a striking result has enormous consequences, both theoretical and practical.
First, is gives strong support to a new vision of condensed matter systems where coherence mechanisms play a fundamental rôle.
Second, it opens the possibility of designing new detectors in the field, for example, of neutrino physics where at present very large, complicated and expensive detectors must be used due to the extremely small (incoherent) neutrino cross section.

The activity of Pirelli Labs in this field is dedicated to the experimental confirmation of Weber's ideas and to the attainment of a sufficient knowledge of the effect for being able to design new experiments. The experimental research program, entirely carried out at Pirelli Labs, includes the detection of visible light absorption by a tightly bound ensemble of polarized nuclear spins in a stiff crystal and the detection of the radiation pressure of solar neutrinos due to elastic scattering. If proved successful, a new era in the field of telecommunications appears possible with the use of neutrinos as a means for data transmission. Neutrinos, differently from radio waves, are able to cross the entire Earth without absorption.