How to observe 8B solar neutrinos in liquid scintillator detectors

Abstract We show that liquid organic scintillator detectors (e.g., KamLAND and Borexino) can measure the 8 B solar neutrino flux by means of the ν e charged current interaction with the 13 C nuclei naturally contained in the scintillators. The neutrino events can be identified by exploiting the time and space coincidence with the subsequent decay of the produced 13 N nuclei. We perform a detailed analysis of the background in KamLAND, Borexino and in a possible liquid scintillator detector at SNOlab, showing that the 8 B solar neutrino signal can be extracted with a reasonable uncertainty in a few years of data taking. KamLAND should be able to extract about 18 solar neutrino events from the already collected data. Prospects for gigantic scintillator detectors (such as LENA) are also studied.