The indication for ${}^{40}$K geo-antineutrino flux with Borexino phase-III data

We provide the indication of high flux of ${}^{40}$K geo-antineutrino and geo-neutrino (${}^{40}$K-geo-($\bar{\nu }+\nu$)) with Borexino Phase III data. This result was obtained by introducing a new source of single events, namely ${}^{40}$K-geo-($\bar{\nu }+\nu$) scattering on electrons, in multivariate fit analysis of Borexino Phase III data. Simultaneously we obtained the count rates of events from ${}^7$Be, $pep$ and CNO solar neutrinos. These count rates are consistent with the prediction of the Low metallicity Sun model SSM B16-AGSS09. MC pseudo-experiments showed that the case of High metallicity Sun and absence of ${}^{40}$K-geo-($\bar{\nu }+\nu$) can not imitate the result of multivariate fit analysis of Borexino Phase III data with introducing ${}^{40}$K-geo-($\bar{\nu }+\nu$) events. We also provide arguments for the high abundance of potassium in the Earth.