1. Experimental evidence of neutrinos produced in the CNO fusion cycle in the Sun
- Author
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Agostini, M., Altenmüller, K., Appel, S., Atroshchenko, V., Bagdasarian, Z., Basilico, D., Bellini, G., Benziger, J., Biondi, R., Bravo, D., Caccianiga, B., Calaprice, F., Caminata, A., Cavalcante, P., Chepurnov, A., D’Angelo, D., Davini, S., Derbin, A., Di Giacinto, A., Di Marcello, V., Ding, X. F., Di Ludovico, A., Di Noto, L., Drachnev, I., Formozov, A., Franco, D., Galbiati, C., Ghiano, C., Giammarchi, M., Goretti, A., Göttel, A. S., Gromov, M., Guffanti, D., Ianni, Aldo, Ianni, Andrea, Jany, Anna, Jeschke, D., Kobychev, V., Korga, G., Kumaran, S., Laubenstein, M., Litvinovich, E., Lombardi, P., Lomskaya, I., Ludhova, L., Lukyanchenko, G., Lukyanchenko, L., Machulin, I., Martyn, J., Meroni, E., Meyer, M., Miramonti, L., Misiaszek, Marcin, Muratova, V., Neumair, B., Nieslony, M., Nugmanov, R., Oberauer, L., Orekhov, V., Ortica, F., Pallavicini, M., Papp, L., Pelicci, L., Penek, Ö., Pietrofaccia, L., Pilipenko, N., Pocar, A., Raikov, G., Ranalli, M. T., Ranucci, G., Razeto, A., Re, A., Redchuk, M., Romani, A., Rossi, N., Schönert, S., Semenov, D., Settanta, G., Skorokhvatov, M., Singhal, A., Smirnov, O., Sotnikov, A., Suvorov, Y., Tartaglia, R., Testera, G., Thurn, J., Unzhakov, E., Villante, F. L., Vishneva, A., Vogelaar, R. B., von Feilitzsch, F., Wójcik, Marcin, Wurm, M., Zavatarelli, S., Zuber, K., Zuzel, Grzegorz, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), BOREXINO, Agostini, M., Altenmuller, K., Appel, S., Atroshchenko, V., Bagdasarian, Z., Basilico, D., Bellini, G., Benziger, J., Biondi, R., Bravo, D., Caccianiga, B., Calaprice, F., Caminata, A., Cavalcante, P., Chepurnov, A., D'Angelo, D., Davini, S., Derbin, A., Di Giacinto, A., Di Marcello, V., Ding, X. F., Di Ludovico, A., Di Noto, L., Drachnev, I., Formozov, A., Franco, D., Galbiati, C., Ghiano, C., Giammarchi, M., Goretti, A., Gottel, A. S., Gromov, M., Guffanti, D., Ianni, A., Jany, A., Jeschke, D., Kobychev, V., Korga, G., Kumaran, S., Laubenstein, M., Litvinovich, E., Lombardi, P., Lomskaya, I., Ludhova, L., Lukyanchenko, G., Lukyanchenko, L., Machulin, I., Martyn, J., Meroni, E., Meyer, M., Miramonti, L., Misiaszek, M., Muratova, V., Neumair, B., Nieslony, M., Nugmanov, R., Oberauer, L., Orekhov, V., Ortica, F., Pallavicini, M., Papp, L., Pelicci, L., Penek, O., Pietrofaccia, L., Pilipenko, N., Pocar, A., Raikov, G., Ranalli, M. T., Ranucci, G., Razeto, A., Re, A., Redchuk, M., Romani, A., Rossi, N., Schonert, S., Semenov, D., Settanta, G., Skorokhvatov, M., Singhal, A., Smirnov, O., Sotnikov, A., Suvorov, Y., Tartaglia, R., Testera, G., Thurn, J., Unzhakov, E., Villante, F. L., Vishneva, A., Vogelaar, R. B., von Feilitzsch, F., Wojcik, M., Wurm, M., Zavatarelli, S., Zuber, K., Zuzel, G., Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Agostini, M, Altenmuller, K, Appel, S, Atroshchenko, V, Bagdasarian, Z, Basilico, D, Bellini, G, Benziger, J, Biondi, R, Bravo, D, Caccianiga, B, Calaprice, F, Caminata, A, Cavalcante, P, Chepurnov, A, D'Angelo, D, Davini, S, Derbin, A, Di Giacinto, A, Di Marcello, V, Ding, X, Di Ludovico, A, Di Noto, L, Drachnev, I, Formozov, A, Franco, D, Galbiati, C, Ghiano, C, Giammarchi, M, Goretti, A, Gottel, A, Gromov, M, Guffanti, D, Ianni, A, Jany, A, Jeschke, D, Kobychev, V, Korga, G, Kumaran, S, Laubenstein, M, Litvinovich, E, Lombardi, P, Lomskaya, I, Ludhova, L, Lukyanchenko, G, Lukyanchenko, L, Machulin, I, Martyn, J, Meroni, E, Meyer, M, Miramonti, L, Misiaszek, M, Muratova, V, Neumair, B, Nieslony, M, Nugmanov, R, Oberauer, L, Orekhov, V, Ortica, F, Pallavicini, M, Papp, L, Pelicci, L, Penek, O, Pietrofaccia, L, Pilipenko, N, Pocar, A, Raikov, G, Ranalli, M, Ranucci, G, Razeto, A, Re, A, Redchuk, M, Romani, A, Rossi, N, Schonert, S, Semenov, D, Settanta, G, Skorokhvatov, M, Singhal, A, Smirnov, O, Sotnikov, A, Suvorov, Y, Tartaglia, R, Testera, G, Thurn, J, Unzhakov, E, Villante, F, Vishneva, A, Vogelaar, R, von Feilitzsch, F, Wojcik, M, Wurm, M, Zavatarelli, S, Zuber, K, and Zuzel, G
- Subjects
CNO cycle ,fusion ,Physics - Instrumentation and Detectors ,Hydrogen ,neutrino: solar ,Physics::Instrumentation and Detectors ,Astrophysics ,G.3.1 ,7. Clean energy ,01 natural sciences ,neutrino: flux ,nitrogen ,High Energy Physics - Experiment ,High Energy Physics - Experiment (hep-ex) ,Solar core ,star ,[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex] ,Astrophysics::Solar and Stellar Astrophysics ,solar neutrinos, CNO-cycle, liquid scintillators, detector ,capture: solar ,Borexino ,neutrino: interaction ,Physics ,Multidisciplinary ,Instrumentation and Detectors (physics.ins-det) ,Astrophysics - Solar and Stellar Astrophysics ,ddc:500 ,Neutrino ,Astrophysics - Instrumentation and Methods for Astrophysics ,Particle physics ,Metallicity ,FOS: Physical sciences ,chemistry.chemical_element ,0103 physical sciences ,Borexino, neutrino, CNO, Sun ,[PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det] ,010306 general physics ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,Solar and Stellar Astrophysics (astro-ph.SR) ,Helium ,Astrophysics::Galaxy Astrophysics ,010308 nuclear & particles physics ,carbon ,Gran Sasso ,85-05 ,Stars ,chemistry ,13. Climate action ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,oxygen ,experimental results - Abstract
For most of their existence stars are fueled by the fusion of hydrogen into helium proceeding via two theoretically well understood processes, namely the $pp$ chain and the CNO cycle. Neutrinos emitted along such fusion processes in the solar core are the only direct probe of the deep interior of the star. A complete spectroscopy of neutrinos from the {\it pp} chain, producing about 99\% of the solar energy, has already been performed \cite{bib:Nature-2018}. Here, we report the direct observation, with a high statistical significance, of neutrinos produced in the CNO cycle in the Sun. This is the first experimental evidence of this process obtained with the unprecedentedly radio-pure large-volume liquid-scintillator Borexino detector located at the underground Laboratori Nazionali del Gran Sasso in Italy. The main difficulty of this experimental effort is to identify the excess of the few counts per day per 100 tonnes of target due to CNO neutrino interactions above the backgrounds. A novel method to constrain the rate of \bi contaminating the scintillator relies on the thermal stabilisation of the detector achieved over the past 5 years. In the CNO cycle, the hydrogen fusion is catalyzed by the carbon (C) - nitrogen (N) - oxygen (O) and thus its rate, as well as the flux of emitted CNO neutrinos, directly depends on the abundance of these elements in solar core. Therefore, this result paves the way to a direct measurement of the solar metallicity by CNO neutrinos. While this result quantifies the relative contribution of the CNO fusion in the Sun to be of the order of 1\%, this process is dominant in the energy production of massive stars. The occurrence of the primary mechanism for the stellar conversion of hydrogen into helium in the Universe has been proven., 43 pages, 14 figures
- Published
- 2020