Simultaneous precision spectroscopy of pp, 7Be and pep solar neutrinos with Borexino Phase-II

We present the simultaneous measurement of the interaction rates ${}_{pp}$, $R_{\mathrm{Be}}$, $R_{pep}$ of $pp$, $7\mathrm{Be}$, and $pep$ solar neutrinos performed with a global fit to the Borexino data in an extended energy range (0.19–2.93) MeV with particular attention to details of the analysis methods. This result was obtained by analyzing 1291.51 days of Borexino Phase-II data, collected after an extensive scintillator purification campaign. Using counts per day $\left(\mathrm{cpd}\right)/100\mathrm{ton}$ as unit, we find $R_{pp}=134\pm 10\left(\mathrm{stat}{)}_{-10}^{+6}\right(\mathrm{sys})$, $R_{Be}=48.3\pm 1.1\left(\mathrm{stat}{)}_{-0.7}^{+0.4}\right(\mathrm{sys})$and $R_{pep}^{\mathrm{HZ}}=2.43\pm 0.36\left(\mathrm{stat}{)}_{-0.22}^{+0.15}\right(\mathrm{sys})$ assuming the interaction rate $R_{\mathrm{CNO}}$ of CNO-cycle (Carbon, Nitrogen, Oxigen) solar neutrinos according to the prediction of the high metallicity standard solar model, and $R_{pep}^{\mathrm{LZ}}=2.65\pm 0.36\left(\mathrm{stat}{)}_{-0.24}^{+0.15}\right(\mathrm{sys})$ according to that of the low metallicity model. An upper limit $R_{\mathrm{CNO}}<8.1\mathrm{cpd}/100\mathrm{ton}$ (95% C.L.) is obtained by setting in the fit a constraint on the ratio $R_{pp}/R_{pep}$ ($47.7\pm 0.8\mathrm{cpd}/100\mathrm{ton}$ or $47.5\pm 0.8\mathrm{cpd}/100\mathrm{ton}$ according to the high or low metallicity hypothesis).