Physicists Detect Solar CNO Neutrinos for First Time | Physics - Sci-News.com

Now, physicists from the Borexino Collaboration report the direct observation of neutrinos produced in the CNO cycle in the Sun.

This experimental evidence was obtained using a large-volume neutrino detector called Borexino, which is located at the underground Laboratori Nazionali del Gran Sasso in Italy.

The Borexino detector lies deep under the Apennine Mountains in central Italy at the INFN’s Laboratori Nazionali del Gran Sasso.

Until its latest detections, the Borexino Collaboration had successfully measured components of the ‘proton-proton’ solar neutrino fluxes, helped refine neutrino flavor-oscillation parameters, and most impressively, even measured the first step in the cycle: the very low-energy p-p neutrinos.

The Borexino researchers dreamed of expanding the science scope to also look for the CNO neutrinos – in a narrow spectral region with particularly low background – but that prize seemed out of reach.

However, they believed CNO neutrinos might yet be revealed using the additional purification steps and methods they had developed to realize the exquisite detector stability required.

“We were able to detect CNO neutrinos using the Borexino experiment’s huge detector located 1,400 m underground,” said Professor Michael Wurm, a neutrino physicist at the PRISMA+ Cluster of Excellence at Johannes Gutenberg University Mainz.