Measurement of the 8B solar neutrino flux with the KamLAND liquid scintillator detector

S. Abe , K. Furuno , A. Gando , Y. Gando , K. Ichimura , H. Ikeda , K. Inoue , Y. Kibe , W. Kimura , Y. Kishimoto , M. Koga , Y. Minekawa , T. Mitsui , T. Morikawa , N. Nagai , K. Nakajima , K. Nakamura , M. Nakamura , K. Narita , I. Shimizu , Y. Shimizu , J. Shirai , F. Suekane , A. Suzuki , H. Takahashi , N. Takahashi , Y. Takemoto , K. Tamae , H. Watanabe , B. D. Xu , H. Yabumoto , E. Yonezawa , H. Yoshida (1) , S. Yoshida (1) , S. Enomoto , A. Kozlov , H. Murayama , C. Grant , G. Keefer , D. Mckee , A. Piepke , T. I. Banks , T. Bloxham , J. A. Detwiler , S. J. Freedman , B. K. Fujikawa , K. Han (2, 3) , R. Kadel , T. O'Donnell , H. M. Steiner , L. A. Winslow , D.A. Dwyer , C. Mauger , R. D. Mckeown , C. Zhang , B. E. Berger , C. E. Lane , J. Maricic , T. Miletic , M. Batygov , J. G. Learned , S. Matsuno , S. Pakvasa , M. Sakai , G. A. Horton-Smith , A. Tang , K. E. Downum , G. Gratta , K. Tolich , Y. Efremenko , Y. Kamyshkov , O. Perevozchikov , H. J. Karwowski , D. M. Markoff , W. Tornow , K. M. Heeger , F. Piquemal (4) , J.-S. Ricol , M.P. Decowski

1 Research Center for Neutrino Science [Sendai]
2 Department of Physics [Berkeley]
3 LBNL - Lawrence Berkeley National Laboratory [Berkeley]
4 NEMO - Neutrino et Faibles Radioactivités

We report a measurement of the neutrino-electron elastic scattering rate from 8B solar neutrinos based on a 123 kton-day exposure of KamLAND. The background-subtracted electron recoil rate, above a 5.5-MeV analysis threshold is 1.49 ± 0.14(stat) ± 0.17(syst) events per kton-day. Interpreted as due to a pure electron flavor flux with a 8B neutrino spectrum, this corresponds to a spectrum integrated flux of 2.77 ± 0.26(stat) ± 0.32(syst) ×106 cm−2s−1. The analysis threshold is driven by 208Tl present in the liquid scintillator, and the main source of systematic uncertainty is due to background from cosmogenic 11Be. The measured rate is consistent with existing measurements and with standard solar model predictions which include matter-enhanced neutrino oscillatio

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

S. Abe, K. Furuno, A. Gando, Y. Gando, K. Ichimura, et al.. Measurement of the 8B solar neutrino flux with the KamLAND liquid scintillator detector. Physical Review C, 2011, 84, pp.035804. ⟨10.1103/PhysRevC.84.035804⟩. ⟨in2p3-00656458⟩