http://arxiv.org/abs/2205.15975
We present an improved measurement of the CNO solar neutrino interaction rate at Earth obtained with the complete Borexino Phase-III dataset. The measured rate R${\rm CNO}$ = $6.7^{+2.0}{-0.8}$ counts/(day$ \cdot$ 100 tonnes), allows us to exclude the absence of the CNO signal with about 7$\sigma$ C.L. The correspondent CNO neutrino flux is $6.6^{+2.0}{-0.9} \times 10^8$ cm$^{-2}$ s$^{-1}$, taking into account the neutrino flavor conversion. We use the new CNO measurement to evaluate the C and N abundances in the Sun with respect to the H abundance for the first time with solar neutrinos. Our result of $N{\rm CN}$ = $(5.78^{+1.86}_{-1.00})\times10^{-4}$ displays a $\sim$2$\sigma$ tension with the “low metallicity” spectroscopic photospheric measurements. On the other hand, our result used together with the $^7$Be and $^8$B solar neutrino fluxes, also measured by Borexino, permits to disfavour at 3.1$\sigma$ C.L. the “low metallicity” SSM B16-AGSS09met as an alternative to the “high metallicity” SSM B16-GS98.
S. Appel, Z. Bagdasarian, D. Basilico, et. al.
Wed, 1 Jun 22
49/65
Comments: 8 pages, 6 figures