An F P, Bai W D, Balantekin A B, Bishai M, Blyth S, Cao G F, Cao J, Chang J F, Chang Y, Chen H S, Chen H Y, Chen S M, Chen Y, Chen Y X, Cheng J, Cheng Z K, Cherwinka J J, Chu M C, Cummings J P, Dalager O, Deng F S, Ding Y Y, Diwan M V, Dohnal T, Dolzhikov D, Dove J, Dwyer D A, Gallo J P, Gonchar M, Gong G H, Gong H, Gu W Q, Guo J Y, Guo L, Guo X H, Guo Y H, Guo Z, Hackenburg R W, Hans S, He M, Heeger K M, Heng Y K, Hor Y K, Hsiung Y B, Hu B Z, Hu J R, Hu T, Hu Z J, Huang H X, Huang J H, Huang X T, Huang Y B, Huber P, Jaffe D E, Jen K L, Ji X L, Ji X P, Johnson R A, Jones D, Kang L, Kettell S H, Kohn S, Kramer M, Langford T J, Lee J, Lee J H C, Lei R T, Leitner R, Leung J K C, Li F, Li H L, Li J J, Li Q J, Li R H, Li S, Li S C, Li W D, Li X N, Li X Q, Li Y F, Li Z B, Liang H, Lin C J, Lin G L, Lin S, Ling J J, Link J M, Littenberg L, Littlejohn B R, Liu J C, Liu J L, Liu J X, Lu C, Lu H Q, Luk K B, Ma B Z, Ma X B, Ma X Y, Ma Y Q, Mandujano R C, Marshall C, McDonald K T, McKeown R D, Meng Y, Napolitano J, Naumov D, Naumova E, Nguyen T M T, Ochoa-Ricoux J P, Olshevskiy A, Pan H-R, Park J, Patton S, Peng J C, Pun C S J, Qi F Z, Qi M, Qian X, Raper N, Ren J, Morales Reveco C, Rosero R, Roskovec B, Ruan X C, Steiner H, Sun J L, Tmej T, Treskov K, Tse W-H, Tull C E, Viren B, Vorobel V, Wang C H, Wang J, Wang M, Wang N Y, Wang R G, Wang W, Wang X, Wang Y, Wang Y F, Wang Z, Wang Z, Wang Z M, Wei H Y, Wei L H, Wen L J, Whisnant K, White C G, Wong H L H, Worcester E, Wu D R, Wu Q, Wu W J, Xia D M, Xie Z Q, Xing Z Z, Xu H K, Xu J L, Xu T, Xue T, Yang C G, Yang L, Yang Y Z, Yao H F, Ye M, Yeh M, Young B L, Yu H Z, Yu Z Y, Yue B B, Zavadskyi V, Zeng S, Zeng Y, Zhan L, Zhang C, Zhang F Y, Zhang H H, Zhang J L, Zhang J W, Zhang Q M, Zhang S Q, Zhang X T, Zhang Y M, Zhang Y X, Zhang Y Y, Zhang Z J, Zhang Z P, Zhang Z Y, Zhao J, Zhao R Z, Zhou L, Zhuang H L, Zou J H
Sun Yat-Sen (Zhongshan) University, Guangzhou.
University of Wisconsin, Madison, Wisconsin 53706.
Phys Rev Lett. 2022 Jul 22;129(4):041801. doi: 10.1103/PhysRevLett.129.041801.
This Letter reports the first measurement of high-energy reactor antineutrinos at Daya Bay, with nearly 9000 inverse beta decay candidates in the prompt energy region of 8-12 MeV observed over 1958 days of data collection. A multivariate analysis is used to separate 2500 signal events from background statistically. The hypothesis of no reactor antineutrinos with neutrino energy above 10 MeV is rejected with a significance of 6.2 standard deviations. A 29% antineutrino flux deficit in the prompt energy region of 8-11 MeV is observed compared to a recent model prediction. We provide the unfolded antineutrino spectrum above 7 MeV as a data-based reference for other experiments. This result provides the first direct observation of the production of antineutrinos from several high-Q_{β} isotopes in commercial reactors.
本信函报道了大亚湾对高能反应堆反中微子的首次测量结果，在1958天的数据采集过程中，在8 - 12兆电子伏特的瞬发能量区域观测到近9000个逆β衰变候选事例。采用多变量分析从统计上分离出2500个信号事例与本底。中微子能量高于10兆电子伏特的反应堆反中微子不存在这一假设被以6.2个标准差的显著性予以否定。与最近的模型预测相比，在8 - 11兆电子伏特的瞬发能量区域观测到29%的反中微子通量亏损。我们给出了7兆电子伏特以上的展开反中微子能谱，作为基于数据的其他实验的参考。这一结果首次直接观测到了商用反应堆中几种高Qβ同位素产生反中微子的情况。
