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ID:
494357.0,
MPI für Kernphysik / Neutrino Physics |
Observation of geo-neutrinos |
Authors: | Bellini, G.; Benziger, J.; Bonetti, S.; Buizza Avanzini, M.; Caccianiga, B.; Cadonati, L.; Calaprice, F.; Carraro, C.; Chavarria, A.; Dalnoki-Veress, F.; D'Angelo, D.; Davini, S.; de Kerret, H.; Derbin, A.; Etenko, A.; Fiorentini, G.; Fomenko, K.; Franco, D.; Galbiati, C.; Gazzana, S.; Ghiano, C.; Giammarchi, M.; Goeger-Neff, M.; Goretti, A.; Gurdincerri, E.; Hardy, S.; Ianni, Aldo; Ianni, Andrea; Joyce, M.; Kobychev, V.V.; Koshio, Y.; Korga, G.; Kryn, D.; Laubenstein, M.; Leung, M.; Lewke, T.; Litvinovich, E.; Loer, B.; Lombardi, P.; Ludhova, L.; Machulin, I.; Manecki, S.; Maneschg, W.; Manuzio, G.; Meindl, Q.; Meroni, E.; Miramonti, L.; Misiaszek, M.; Montanari, D.; Muratova, V.; Oberauer, L.; Obolensky, M.; Ortica, F.; Pallavicini, M.; Papp, L.; Perasso, L.; Perasso, S.; Pocar, A.; Raghavan, R.S.; Ranucci, G.; Razeto, A.; Re, A.; Ricci, B.; Risso, P.; Romani, A.; Rountree, D.; Sabelnikov, A.; Saldanha, R.; Salvo, C.; Schönert, S.; Simgen, H.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Sukhotin, S.; Suvorov, Y.; Tartaglia, R.; Testera, G.; Vinaud, D.; Vogelaar, R.B.; von Feilitzsch, F.; Winter, J.; Wojcik, M.; Wright, A.; Wurm, M.; Xu, J.; Zaimidoroga, O.; Zavatarelli, S.; Zuzel, G. | Language: | English | Date of Publication (YYYY-MM-DD): | 2010-04-19 | Title of Journal: | Physics Letters B | Journal Abbrev.: | Phys. Lett. B | Volume: | 687 | Issue / Number: | 4-5 | Start Page: | 299 | End Page: | 304 | Review Status: | not specified | Audience: | Experts Only | Abstract / Description: | Geo-neutrinos, electron anti-neutrinos produced in beta decays of naturally occurring radioactive isotopes in the Earth, are a unique direct probe of our planet's interior. We report the first observation at more than 3$\sigma$ C.L. of geo-neutrinos, performed with the Borexino detector at Laboratori Nazionali del Gran Sasso. Anti-neutrinos are detected through the neutron inverse beta decay reaction. With a 252.6 ton-yr fiducial exposure after all selection cuts, we detected 9.9^{+4.1}_{-3.4}(^{+14.6}_{-8.2}) geo-neutrino events, with errors corresponding to a 68.3%(99.73%) C.L. From the $\ln{\cal{L}}$ profile, the statistical significance of the Borexino geo-neutrino observation corresponds to a 99.997% C.L. Our measurement of the geo-neutrinos rate is 3.9^{+1.6}_{-1.3}(^{+5.8}_{-3.2}) events/(100ton-yr). This measurement rejects the hypothesis of an active geo-reactor in the Earth's core with a power above 3 TW at 95% C.L. The observed prompt positron spectrum above 2.6 MeV is compatible with that expected from european nuclear reactors (mean base line of approximately 1000 km). Our measurement of reactor anti-neutrinos excludes the non-oscillation hypothesis at 99.60% C.L. | External Publication Status: | published | Document Type: | Article |
Affiliations: | MPI für Kernphysik/Group of M. Lindner
| Identifiers: | URL:http://dx.doi.org/10.1016/j.physletb.2010.03.051 DOI:10.1016/j.physletb.2010.03.051 | |
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