We report an improved geoneutrino measurement with Borexino from 2056 days of data taking. The present exposure is (5.5±0.3)×1031 proton×yr. Assuming a chondritic Th/U mass ratio of 3.9, we obtain 23.7-5.7+6.5(stat)-0.6+0.9(sys) geoneutrino events. The null observation of geoneutrinos with Borexino alone has a probability of 3.6×10-9 (5.9σ). A geoneutrino signal from the mantle is obtained at 98% C.L. The radiogenic heat production for U and Th from the present best-fit result is restricted to the range 23-36 TW, taking into account the uncertainty on the distribution of heat producing elements inside the Earth.
|Original language||English (US)|
|Journal||Physical Review D - Particles, Fields, Gravitation and Cosmology|
|State||Published - Aug 7 2015|
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics
- Physics and Astronomy (miscellaneous)