The Borexino experiment has recently provided the first direct experimental evidence of the sub-dominant CNO-cycle in the Sun, which is assumed to be the main energy production mechanism in heavier stars. Borexino is a liquid scintillator detector located at the Laboratori Nazionali del Gran Sasso, Italy with the main goal to measure solar neutrinos. The extreme radiopurity of the scintillator and the successful thermal stabilisation of the detector have proven to be valuable assets in the quest for CNO neutrinos. The low abundance of CNO neutrinos and the similarity of its spectral shape to that of pep solar neutrinos and the intrinsic 210Bi background, make CNO neutrino detection challenging. Therefore, it is necessary to constrain these backgrounds independently. The energy and radial distribution of the events can then be exploited to perform a multivariate fit, which requires a careful evaluation of the systematic uncertainty associated with the Monte-Carlo spectral shapes used. Borexino has successfully rejected the null hypothesis of CNO-cycle neutrinos in the Sun with greater than 5.0σ significance with 99% C.L. This article will present the overview of the strategy and methods used to achieve this result and the consequence of this result for solar and stellar physics.

First direct evidence of the CNO fusion cycle in the Sun with Borexino / S. Kumaran, M. Agostini, K. Altenmuller, S. Appel, V. Atroshchenko, Z. Bagdasarian, D. Basilico, G. Bellini, J. Benziger, R. Biondi, D. Bravo, B. Caccianiga, F. Calaprice, A. Caminata, P. Cavalcante, A. Chepurnov, D. D'Angelo, S. Davini, A. Derbin, A. Di Giacinto, V. Di Marcello, X.F. Ding, A. Di Ludovico, L. Di Noto, I. Drachnev, A. Formozov, D. Franco, C. Galbiati, C. Ghiano, M. Giammarchi, A. Goretti, A.S. Gottel, M. Gromov, D. Guffanti, A. Ianni, A. Ianni, A. Jany, D. Jeschke, V. Kobychev, G. Korga, S. Kumaran, M. Laubenstein, E. Litvinovich, P. Lombardi, I. Lomskaya, L. Ludhova, G. Lukyanchenko, L. Lukyanchenko, I. Machulin, J. Martyn, E. Meroni, M. Meyer, L. Miramonti, M. Misiaszek, V. Muratova, B. Neumair, M. Nieslony, R. Nugmanov, L. Oberauer, V. Orekhov, F. Ortica, M. Pallavicini, L. Papp, L. Pelicci, O. Penek, L. Pietrofaccia, N. Pilipenko, A. Pocar, G. Raikov, M.T. Ranalli, G. Ranucci, A. Razeto, A. Re, M. Redchuk, A. Romani, N. Rossi, S. Schonert, D. Semenov, G. Settanta, M. Skorokhvatov, A. Singhal, O. Smirnov, A. Sotnikov, Y. Suvorov, R. Tartaglia, G. Testera, J. Thurn, E. Unzhakov, F.L. Villante, A. Vishneva, R.B. Vogelaar, F. von Feilitzsch, M. Wojcik, M. Wurm, S. Zavatarelli, K. Zuber, G. Zuzel. - In: POS PROCEEDINGS OF SCIENCE. - ISSN 1824-8039. - 395:(2022), pp. 1109.1-1109.9. ((Intervento presentato al 37. convegno ICRC : International Cosmic Ray Conference : NU - Neutrinos & Muons : 12 1through 23 July nel 2021.

First direct evidence of the CNO fusion cycle in the Sun with Borexino

D. Basilico;G. Bellini;B. Caccianiga;L. Miramonti;A. Re;
2022

Abstract

The Borexino experiment has recently provided the first direct experimental evidence of the sub-dominant CNO-cycle in the Sun, which is assumed to be the main energy production mechanism in heavier stars. Borexino is a liquid scintillator detector located at the Laboratori Nazionali del Gran Sasso, Italy with the main goal to measure solar neutrinos. The extreme radiopurity of the scintillator and the successful thermal stabilisation of the detector have proven to be valuable assets in the quest for CNO neutrinos. The low abundance of CNO neutrinos and the similarity of its spectral shape to that of pep solar neutrinos and the intrinsic 210Bi background, make CNO neutrino detection challenging. Therefore, it is necessary to constrain these backgrounds independently. The energy and radial distribution of the events can then be exploited to perform a multivariate fit, which requires a careful evaluation of the systematic uncertainty associated with the Monte-Carlo spectral shapes used. Borexino has successfully rejected the null hypothesis of CNO-cycle neutrinos in the Sun with greater than 5.0σ significance with 99% C.L. This article will present the overview of the strategy and methods used to achieve this result and the consequence of this result for solar and stellar physics.
Settore FIS/01 - Fisica Sperimentale
2022
18-mar-2022
International School for Advanced Studies (SISSA)
Article (author)
File in questo prodotto:
File Dimensione Formato  
ICRC2021_1109.pdf

accesso aperto

Tipologia: Publisher's version/PDF
Dimensione 1.42 MB
Formato Adobe PDF
1.42 MB Adobe PDF Visualizza/Apri
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/951187
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 0
  • ???jsp.display-item.citation.isi??? ND
social impact