Feasibility and physics potential of detecting <sup>8</sup>B solar neutrinos at JUNO *
A. C. Abusleme Hoffman, Thomas Adam, S. Ahmad, S. Aiello, M. Akram, Nawab Ali, Fengpeng An, Guangpeng An, Qi An, Giuseppe Andronico, Н. Анфимов, V. Antonelli, Tatiana Antoshkina, Burin Asavapibhop, J. P. A. M. de André, Didier Auguste, Andrej Babič, W. Baldini, Andrea Barresi, E. Baussan, Marco Bellato, Antonio Bergnoli, E. Bernieri, David Biaré, Thilo Birkenfeld, Sylvie Blin, David Blum, S.C. Blyth, Anastasia Bolshakova, M. Bongrand, Clément Bordereau, D. Breton, A. Brigatti, R. Brugnera, Riccardo Bruno, A. Budano, Max Buesken, Mario Buscemi, José Busto, Ilya Butorov, J. Busenitz, Hao Cai, X. Cai, Yanke Cai, Zhiyan Cai, Antonio Cammi, Agustín Campeny, Chuanya Cao, Guofu Cao, Jun Cao, R. Caruso, C. Cerna, J. F. Chang, Yun Chang, Pingping Chen, Po-An Chen, Shaomin Chen, Shenjian Chen, Xurong Chen, Yiwen Chen, Yixue Chen, Yu Chen, Zhang Chen, Jie Cheng, Yaping Cheng, Alexander Chepurnov, D. Chiesa, P. Chimenti, A. Chukanov, Anna Chuvashova, Gérard Claverie, Catia Clementi, Barbara Clerbaux, Selma Conforti Di Lorenzo, Daniele Corti, S. Costa, Flavio Dal Corso, C. De La Taille, Jiawei Deng, Zhi Deng, Ziyan Deng, Wilfried Depnering, Marco Diaz, Xuefeng Ding, Yayun Ding, Bayu Dirgantara, Sergey Dmitrievsky, Tadeáš Dohnal, Georgy Donchenko, J. Dong, Damien Dornic, Evgeny Doroshkevich, M. Dracos, Frédéric Druillole, Shuxian Du, Stefano Dusini, Martin Dvořák, T. Enqvist, Heike Enzmann, Andrea Fabbri
Abstract
Abstract The Jiangmen Underground Neutrino Observatory (JUNO) features a 20 kt multi-purpose underground liquid scintillator sphere as its main detector. Some of JUNO's features make it an excellent location for B solar neutrino measurements, such as its low-energy threshold, high energy resolution compared with water Cherenkov detectors, and much larger target mass compared with previous liquid scintillator detectors. In this paper, we present a comprehensive assessment of JUNO's potential for detecting B solar neutrinos via the neutrino-electron elastic scattering process. A reduced 2 MeV threshold for the recoil electron energy is found to be achievable, assuming that the intrinsic radioactive background U and Th in the liquid scintillator can be controlled to 10 g/g. With ten years of data acquisition, approximately 60,000 signal and 30,000 background events are expected. This large sample will enable an examination of the distortion of the recoil electron spectrum that is dominated by the neutrino flavor transformation in the dense solar matter, which will shed new light on the inconsistency between the measured electron spectra and the predictions of the standard three-flavor neutrino oscillation framework. If eV , JUNO can provide evidence of neutrino oscillation in the Earth at approximately the 3 (2 ) level by measuring the non-zero signal rate variation with respect to the solar zenith angle. Moreover, JUNO can simultaneously measure using B solar neutrinos to a precision of 20% or better, depending on the central value, and to sub-percent precision using reactor antineutrinos. A comparison of these two measurements from the same detector will help understand the current mild inconsistency between the value of reported by solar neutrino experiments and the KamLAND experiment.