KamLAND results and the radiogenic terrestrial heat

We find that recent results from the KamLAND Collaboration on geologically produced antineutrinos, N(U+Th)=28−15+16 events, correspond to a radiogenic heat production from uranium and thorium decay chains H(U+Th)=38−33+35TW. The 99% confidence limit on the geo-neutrino signal translates into the upper bound H(U+Th)<162 TW, which is much weaker than that claimed by KamLAND, H(U+Th)<60TW, based on a too narrow class of geological models. We also performed an analysis of KamLAND data including recent high precision measurements of the 13C(α,n)16O cross section. The result, N(U+Th)=31−13+14, corroborates the evidence (≃2.5σ) for geo-neutrinos in KamLAND data.