(a) The 68.3, 95.4, and 99.7% contour plots of the Th versus U signal, expressed in TNU units, in the Borexino geoneutrino analysis [62]; the dashed blue line is the expectation for a chondritic Th/U mass ratio of 3.9. (b) the same confidence level contours are shown for the KamLAND analysis [51], expressed in number of total events versus the normalized difference of the number of events from U and Th. The vertical dashed line represents the chondritic ratio of 3.9 while the shadowed area on this line is the prediction of the BSE model from [17].
