Final results of Borexino Phase-I on low-energy solar neutrino spectroscopy

被引：242

作者：

Bellini, G. ^{[1
,2
]}

Benziger, J. ^{[3
]}

Bick, D. ^{[4
]}

Bonfini, G. ^{[5
]}

Bravo, D. ^{[6
]}

Avanzini, M. Buizza ^{[1
]}

Caccianiga, B. ^{[1
]}

Cadonati, L. ^{[7
]}

Calaprice, F. ^{[3
]}

Cavalcante, P. ^{[5
]}

Chavarria, A. ^{[3
]}

Chepurnov, A. ^{[8
]}

D'Angelo, D. ^{[1
,2
]}

Davini, S. ^{[9
]}

Derbin, A. ^{[10
]}

Empl, A. ^{[9
]}

Etenko, A. ^{[11
]}

Fomenko, K. ^{[5
,12
]}

Franco, D. ^{[13
]}

Gabriele, F. ^{[5
]}

Galbiati, C. ^{[3
]}

Gazzana, S. ^{[5
]}

Ghiano, C. ^{[13
]}

Giammarchi, M. ^{[1
]}

Goeger-Neff, M. ^{[14
]}

Goretti, A. ^{[3
]}

Grandi, L. ^{[3
]}

Gromov, M. ^{[8
]}

Hagner, C. ^{[4
]}

Hungerford, E. ^{[9
]}

Ianni, Aldo ^{[5
]}

Ianni, Andrea ^{[3
]}

Kobychev, V. ^{[15
]}

Korablev, D. ^{[12
]}

Korga, G. ^{[9
]}

Kryn, D. ^{[13
]}

Laubenstein, M.

Lewke, T. ^{[14
]}

Litvinovich, E. ^{[11
,16
]}

Loer, B. ^{[3
]}

Lombardi, F. ^{[5
]}

Lombardi, P. ^{[1
,2
]}

Ludhova, L. ^{[1
,2
]}

Lukyanchenko, G. ^{[11
]}

Machulin, I. ^{[11
,16
]}

Manecki, S. ^{[6
]}

Maneschg, W. ^{[17
]}

Manuzio, G. ^{[18
,19
]}

Meindl, Q. ^{[14
]}

Meroni, E. ^{[1
,2
]}

机构：

[1] Univ Milan, Dipartimento Fis, I-20133 Milan, Italy

[2] Ist Nazl Fis Nucl, I-20133 Milan, Italy

[3] Princeton Univ, Dept Phys, Princeton, NJ 08544 USA

[4] Univ Hamburg, Inst Expt Phys, Hamburg, Germany

[5] Ist Nazl Fis Nucl, Lab Nazl Gran Sasso, I-67010 Assergi, Italy

[6] Virginia Polytech Inst & State Univ, Dept Phys, Blacksburg, VA 24061 USA

[7] Univ Massachusetts, Dept Phys, Amherst, MA 01003 USA

[8] Moscow MV Lomonosov State Univ, Skobeltsyn Inst Nucl Phys, Moscow 119234, Russia

[9] Univ Houston, Dept Phys, Houston, TX 77204 USA

[10] St Petersburg Nucl Phys Inst, Gatchina 188350, Russia

[11] NRC Kurchatov Inst, Moscow 123182, Russia

[12] Joint Inst Nucl Res, Dubna 141980, Russia

[13] Univ Paris Diderot, Sorbonne Paris Cite, CNRS, IN2P3,CEA Irfu,Obs Paris,APC, Paris, France

[14] Tech Univ Munich, Dept Phys, D-85747 Garching, Germany

[15] Kiev Inst Nucl Res, UA-06380 Kiev, Ukraine

[16] Natl Res Nucl Univ, MEPhI Moscow Engn Phys Inst, Moscow, Russia

[17] Max Planck Inst Kernphys, D-69117 Heidelberg, Germany

[18] Univ Genoa, Dipartimento Fis, I-16146 Genoa, Italy

[19] Ist Nazl Fis Nucl, I-16146 Genoa, Italy

[20] Jagiellonian Univ, M Smoluchowski Inst Phys, PL-30059 Krakow, Poland

[21] Univ Perugia, Dipartimento Chim Biol & Biotecnol, I-06123 Perugia, Italy

[22] Ist Nazl Fis Nucl, I-06123 Perugia, Italy

[23] Ist Fis Corpuscular, E-46071 Valencia, Spain

[24] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA

来源：

PHYSICAL REVIEW D | 2014年 / 89卷 / 11期

基金：

美国国家科学基金会;

关键词：

EMPIRICAL MODE DECOMPOSITION; PULSE-SHAPE DISCRIMINATION; SCINTILLATOR; OSCILLATIONS; SEARCH; MATTER; PROTOTYPE; ABUNDANCE; SPECTRUM; DETECTOR;

D O I：

10.1103/PhysRevD.89.112007

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Borexino has been running since May 2007 at the Laboratori Nazionali del Gran Sasso laboratory in Italy with the primary goal of detecting solar neutrinos. The detector a large unsegmented liquid scintillator calorimeter characterized by unprecedented low levels of intrinsic radioactivity is optimized for the study of the lower energy part of the spectrum. During Phase-I (2007-2010) Borexino first detected and then precisely measured the flux of the Be-7 solar neutrinos ruled out any significant day-night asymmetry of their interaction rate made the first direct observation of the pep neutrinos and set the tightest upper limit on the flux of solar neutrinos produced in the CNO cycle (carbon nitrogen oxigen) where carbon nitrogen and oxygen serve as catalysts in the fusion process. In this paper we discuss the signal signature and provide a comprehensive description of the backgrounds quantify their event rates describe the methods for their identification selection or subtraction and describe data analysis. Key features are an extensive in situ calibration program using radioactive sources the detailed modeling of the detector response the ability to define an innermost fiducial volume with extremely low background via software cuts and the excellent pulse-shape discrimination capability of the scintillator that allows particle identification. We report a measurement of the annual modulation of the Be-7 neutrino interaction rate. The period the amplitude and the phase of the observed modulation are consistent with the solar origin of these events and the absence of their annual modulation is rejected with higher than 99% C.L. The physics implications of Phase-I results in the context of the neutrino oscillation physics and solar models are presented.

引用

页数：68