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Your search keyword '"Whisnant, K."' showing total 21 results
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21 results on '"Whisnant, K."'

1. First measurement of the yield of $^8$He isotopes produced in liquid scintillator by cosmic-ray muons at Daya Bay

Author

Daya Bay Collaboration, 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., Chen, Z. Y., Cheng, J., Cheng, Y. C., Cheng, Z. K., Cherwinka, J. J., Chu, M. C., Cummings, J. P., Dalager, O., Deng, F. S., Ding, X. Y., Ding, Y. Y., Diwan, M. V., Dohnal, T., Dolzhikov, D., Dove, J., Dugas, K. V., Duyang, H. Y., 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., Han, Y., 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., Park, J., Patton, S., Peng, J. C., Pun, C. S. J., Qi, F. Z., Qi, M., Qian, X., Raper, N., Ren, J., Reveco, C. Morales, Rosero, R., Roskovec, B., Ruan, X. C., Russell, B., Steiner, H., Sun, J. L., Tmej, T., Tse, W. -H., Tull, C. E., Tung, Y. C., Viren, B., Vorobel, V., Wang, C. H., Wang, J., Wang, M., Wang, N. Y., Wang, R. G., Wang, W., Wang, X., Wang, Y. F., Wang, Z., Wang, Z. M., Wei, H. Y., Wei, L. H., Wei, W., 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., and Zou, J. H.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

Daya Bay presents the first measurement of cosmogenic $^8$He isotope production in liquid scintillator, using an innovative method for identifying cascade decays of $^8$He and its child isotope, $^8$Li. We also measure the production yield of $^9$Li isotopes using well-established methodology. The results, in units of 10$^{-8}\mu^{-1}$g$^{-1}$cm$^{2}$, are 0.307$\pm$0.042, 0.341$\pm$0.040, and 0.546$\pm$0.076 for $^8$He, and 6.73$\pm$0.73, 6.75$\pm$0.70, and 13.74$\pm$0.82 for $^9$Li at average muon energies of 63.9~GeV, 64.7~GeV, and 143.0~GeV, respectively. The measured production rate of $^8$He isotopes is more than an order of magnitude lower than any other measurement of cosmogenic isotope production. It replaces the results of previous attempts to determine the ratio of $^8$He to $^9$Li production that yielded a wide range of limits from 0 to 30\%. The results provide future liquid-scintillator-based experiments with improved ability to predict cosmogenic backgrounds.

Published
2024

2. First measurement of high-energy reactor antineutrinos at Daya Bay

Author

Daya Bay collaboration, An, F. P., Balantekin, A. B., Band, H. R., Bishai, M., Blyth, S., Cao, G. F., Cao, J., Chang, J. F., Chang, Y., Chen, H. S., 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., Dove, J., Dvorak, M., 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., Higuera, A., Hor, Y. K., Hsiung, Y. B., Hu, B. Z., Hu, J. R., Hu, T., Hu, Z. J., Huang, H. X., 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, J. J., Li, Q. J., 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., Lu, C., Lu, H. Q., Lu, J. S., Luk, K. B., Ma, X. B., Ma, X. Y., Ma, Y. Q., Marshall, C., Caicedo, D. A. Martinez, McDonald, K. T., McKeown, R. D., Meng, Y., Napolitano, J., Naumov, D., Naumova, E., 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., Reveco, C. Morales, 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. 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, F. L., Wu, Q., Wu, W. J., Xia, D. M., Xie, Z. Q., Xing, Z. Z., 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., Zeng, S., Zeng, Y., Zhan, L., Zhang, C., Zhang, F. Y., Zhang, H. H., Zhang, J. W., Zhang, Q. M., Zhang, X. T., Zhang, Y. M., Zhang, Y. X., Zhang, Y. Y., Zhang, Z. J., Zhang, Z. P., Zhang, Z. Y., Zhao, J., Zhou, L., Zhuang, H. L., and Zou, J. H.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

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-$Q_{\beta}$ isotopes in commercial reactors., Comment: 7 pages, 4 figures, accepted by Physical Review Letters

Published
2022
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3. Joint Determination of Reactor Antineutrino Spectra from $^{235}$U and $^{239}$Pu Fission by Daya Bay and PROSPECT

Author

Daya Bay Collaboration, PROSPECT Collaboration, An, F. P., Andriamirado, M., Balantekin, A. B., Band, H. R., Bass, C. D., Bergeron, D. E., Berish, D., Bishai, M., Blyth, S., Bowden, N. S., Bryan, C. D., Cao, G. F., Cao, J., Chang, J. F., Chang, Y., Chen, H. S., Chen, S. M., Chen, Y., Chen, Y. X., Cheng, J., Cheng, Z. K., Cherwinka, J. J., Chu, M. C., Classen, T., Conant, A. J., Cummings, J. P., Dalager, O., Deichert, G., Delgado, A., Deng, F. S., Ding, Y. Y., Diwan, M. V., Dohnal, T., Dolinski, M. J., Dolzhikov, D., Dove, J., Dvorak, M., Dwyer, D. A., Erickson, A., Foust, B. T., Gaison, J. K., Galindo-Uribarri, A., Gallo, J. P., Gilbert, C. E., Gonchar, M., Gong, G. H., Gong, H., Grassi, M., Gu, W. Q., Guo, J. Y., Guo, L., Guo, X. H., Guo, Y. H., Guo, Z., Hackenburg, R. W., Hans, S., Hansell, A. B., He, M., Heeger, K. M., Heffron, B., 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., Koblanski, J., Jaffe, D. E., Jayakumar, S., Jen, K. L., Ji, X. L., Ji, X. P., Johnson, R. A., Jones, D. C., Kang, L., Kettell, S. H., Kohn, S., Kramer, M., Kyzylova, O., Lane, C. E., Langford, T. J., LaRosa, 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., Lu, X., Luk, K. B., Ma, B. Z., Ma, X. B., Ma, X. Y., Ma, Y. Q., Mandujano, R. C., Maricic, J., Marshall, C., McDonald, K. T., McKeown, R. D., Mendenhall, M. P., Meng, Y., Meyer, A. M., Milincic, R., Mueller, P. E., Mumm, H. P., Napolitano, J., Naumov, D., Naumova, E., Neilson, R., Nguyen, T. M. T., Nikkel, J. A., Nour, S., Ochoa-Ricoux, J. P., Olshevskiy, A., Palomino, J. L., Pan, H. -R., Park, J., Patton, S., Peng, J. C., Pun, C. S. J., Pushin, D. A., Qi, F. Z., Qi, M., Qian, X., Raper, N., Ren, J., Reveco, C. Morales, Rosero, R., Roskovec, B., Ruan, X. C., Searles, M., Steiner, H., Sun, J. L., Surukuchi, P. T., Tmej, T., Treskov, K., Tse, W. -H., Tull, C. E., Tyra, M. A., Varner, R. L., Venegas-Vargas, D., 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. M., Weatherly, P. B., Wei, H. Y., Wei, L. H., Wen, L. J., Whisnant, K., White, C., Wilhelmi, J., Wong, H. L. H., Woolverton, A., Worcester, E., Wu, D. R., Wu, F. L., 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. W., Zhang, Q. M., Zhang, S. Q., Zhang, X., 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., and Zou, J. H.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

A joint determination of the reactor antineutrino spectra resulting from the fission of $^{235}$U and $^{239}$Pu has been carried out by the Daya Bay and PROSPECT collaborations. This Letter reports the level of consistency of $^{235}$U spectrum measurements from the two experiments and presents new results from a joint analysis of both data sets. The measurements are found to be consistent. The combined analysis reduces the degeneracy between the dominant $^{235}$U and $^{239}$Pu isotopes and improves the uncertainty of the $^{235}$U spectral shape to about 3\%. The ${}^{235}$U and $^{239}$Pu antineutrino energy spectra are unfolded from the jointly deconvolved reactor spectra using the Wiener-SVD unfolding method, providing a data-based reference for other reactor antineutrino experiments and other applications. This is the first measurement of the $^{235}$U and $^{239}$Pu spectra based on the combination of experiments at low- and highly enriched uranium reactors., Comment: 8 pages, 5 figures, Supplementary Material Included

Published
2021
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4. Evolution of the Reactor Antineutrino Flux and Spectrum at Daya Bay

Author

An, F. P., Balantekin, A. B., Band, H. R., Bishai, M., Blyth, S., Cao, D., Cao, G. F., Cao, J., Chan, Y. L., Chang, J. F., Chang, Y., Chen, H. S., Chen, Q. Y., Chen, S. M., Chen, Y. X., Chen, Y., Cheng, J., Cheng, Z. K., Cherwinka, J. J., Chu, M. C., Chukanov, A., Cummings, J. P., Ding, Y. Y., Diwan, M. V., Dolgareva, M., Dove, J., Dwyer, D. A., Edwards, W. R., Gill, R., Gonchar, M., Gong, G. H., Gong, H., Grassi, M., Gu, W. Q., Guo, L., Guo, X. H., Guo, Y. H., Guo, Z., Hackenburg, R. W., Hans, S., He, M., Heeger, K. M., Heng, Y. K., Higuera, A., Hsiung, Y. B., Hu, B. Z., Hu, T., Huang, E. C., Huang, H. X., Huang, X. T., Huang, Y. B., Huber, P., Huo, W., Hussain, G., Jaffe, D. E., Jen, K. L., Ji, X. P., Ji, X. L., Jiao, J. B., Johnson, R. A., Jones, D., Kang, L., Kettell, S. H., Khan, A., Kohn, S., Kramer, M., Kwan, K. K., Kwok, M. W., Langford, T. J., Lau, K., Lebanowski, L., Lee, J., Lee, J. H. C., Lei, R. T., Leitner, R., Leung, J. K. C., Li, C., Li, D. J., Li, F., Li, G. S., Li, Q. J., 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., Lin, S. K., Lin, Y. -C., Ling, J. J., Link, J. M., Littenberg, L., Littlejohn, B. R., Liu, J. L., Liu, J. C., Loh, C. W., Lu, C., Lu, H. Q., Lu, J. S., Luk, K. B., Ma, X. Y., Ma, X. B., Ma, Y. Q., Malyshkin, Y., Caicedo, D. A. Martinez, McDonald, K. T., McKeown, R. D., Mitchell, I., Nakajima, Y., Napolitano, J., Naumov, D., Naumova, E., Ngai, H. Y., Ochoa-Ricoux, J. P., Olshevskiy, A., Pan, H. -R., Park, J., Patton, S., Pec, V., Peng, J. C., Pinsky, L., Pun, C. S. J., Qi, F. Z., Qi, M., Qian, X., Qiu, R. M., Raper, N., Ren, J., Rosero, R., Roskovec, B., Ruan, X. C., Steiner, H., Stoler, P., Sun, J. L., Tang, W., Taychenachev, D., Treskov, K., Tsang, K. V., Tull, C. E., Viaux, N., Viren, B., Vorobel, V., Wang, C. H., Wang, M., Wang, N. Y., Wang, R. G., Wang, W., Wang, X., Wang, Y. F., Wang, Z., Wang, Z. M., Wei, H. Y., Wen, L. J., Whisnant, K., White, C. G., Whitehead, L., Wise, T., Wong, H. L. H., Wong, S. C. F., Worcester, E., Wu, C. -H., Wu, Q., Wu, W. J., Xia, D. M., Xia, J. K., Xing, Z. Z., Xu, J. L., Xu, Y., Xue, T., Yang, C. G., Yang, H., Yang, L., Yang, M. S., Yang, M. T., Yang, Y. Z., Ye, M., Ye, Z., Yeh, M., Young, B. L., Yu, Z. Y., Zeng, S., Zhan, L., Zhang, C., Zhang, C. C., Zhang, H. H., Zhang, J. W., Zhang, Q. M., Zhang, R., Zhang, X. T., Zhang, Y. M., Zhang, Y. X., Zhang, Z. J., Zhang, Z. Y., Zhang, Z. P., Zhao, J., Zhou, L., Zhuang, H. L., and Zou, J. H.

Subjects
High Energy Physics - Experiment, Nuclear Experiment, Physics - Instrumentation and Detectors
Abstract

The Daya Bay experiment has observed correlations between reactor core fuel evolution and changes in the reactor antineutrino flux and energy spectrum. Four antineutrino detectors in two experimental halls were used to identify 2.2 million inverse beta decays (IBDs) over 1230 days spanning multiple fuel cycles for each of six 2.9 GW$_{\textrm{th}}$ reactor cores at the Daya Bay and Ling Ao nuclear power plants. Using detector data spanning effective $^{239}$Pu fission fractions, $F_{239}$, from 0.25 to 0.35, Daya Bay measures an average IBD yield, $\bar{\sigma}_f$, of $(5.90 \pm 0.13) \times 10^{-43}$ cm$^2$/fission and a fuel-dependent variation in the IBD yield, $d\sigma_f/dF_{239}$, of $(-1.86 \pm 0.18) \times 10^{-43}$ cm$^2$/fission. This observation rejects the hypothesis of a constant antineutrino flux as a function of the $^{239}$Pu fission fraction at 10 standard deviations. The variation in IBD yield was found to be energy-dependent, rejecting the hypothesis of a constant antineutrino energy spectrum at 5.1 standard deviations. While measurements of the evolution in the IBD spectrum show general agreement with predictions from recent reactor models, the measured evolution in total IBD yield disagrees with recent predictions at 3.1$\sigma$. This discrepancy indicates that an overall deficit in measured flux with respect to predictions does not result from equal fractional deficits from the primary fission isotopes $^{235}$U, $^{239}$Pu, $^{238}$U, and $^{241}$Pu. Based on measured IBD yield variations, yields of $(6.17 \pm 0.17)$ and $(4.27 \pm 0.26) \times 10^{-43}$ cm$^2$/fission have been determined for the two dominant fission parent isotopes $^{235}$U and $^{239}$Pu. A 7.8% discrepancy between the observed and predicted $^{235}$U yield suggests that this isotope may be the primary contributor to the reactor antineutrino anomaly., Comment: 7 pages, 5 figures

Published
2017
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5. Measurement of electron antineutrino oscillation based on 1230 days of operation of the Daya Bay experiment

Author

Daya Bay Collaboration, An, F. P., Balantekin, A. B., Band, H. R., Bishai, M., Blyth, S., Cao, D., Cao, G. F., Cao, J., Cen, W. R., Chan, Y. L., Chang, J. F., Chang, L. C., Chang, Y., Chen, H. S., Chen, Q. Y., Chen, S. M., Chen, Y. X., Chen, Y., Cheng, J. -H., Cheng, J., Cheng, Y. P., Cheng, Z. K., Cherwinka, J. J., Chu, M. C., Chukanov, A., Cummings, J. P., de Arcos, J., Deng, Z. Y., Ding, X. F., Ding, Y. Y., Diwan, M. V., Dolgareva, M., Dove, J., Dwyer, D. A., Edwards, W. R., Gill, R., Gonchar, M., Gong, G. H., Gong, H., Grassi, M., Gu, W. Q., Guan, M. Y., Guo, L., Guo, X. H., Guo, Z., Hackenburg, R. W., Han, R., Hans, S., He, M., Heeger, K. M., Heng, Y. K., Higuera, A., Hor, Y. K., Hsiung, Y. B., Hu, B. Z., Hu, T., Hu, W., Huang, E. C., Huang, H. X., Huang, X. T., Huber, P., Huo, W., Hussain, G., Jaffe, D. E., Jaffke, P., Jen, K. L., Jetter, S., Ji, X. P., Ji, X. L., Jiao, J. B., Johnson, R. A., Jones, D., Joshi, J., Kang, L., Kettell, S. H., Kohn, S., Kramer, M., Kwan, K. K., Kwok, M. W., Kwok, T., Langford, T. J., Lau, K., Lebanowski, L., Lee, J., Lee, J. H. C., Lei, R. T., Leitner, R., Leung, J. K. C., Li, C., Li, D. J., Li, F., Li, G. S., Li, Q. J., Li, S., Li, S. C., Li, W. D., Li, X. N., Li, Y. F., Li, Z. B., Liang, H., Lin, C. J., Lin, G. L., Lin, S., Lin, S. K., Lin, Y. -C., Ling, J. J., Link, J. M., Littenberg, L., Littlejohn, B. R., Liu, D. W., Liu, J. L., Liu, J. C., Loh, C. W., Lu, C., Lu, H. Q., Lu, J. S., Luk, K. B., Lv, Z., Ma, Q. M., Ma, X. Y., Ma, X. B., Ma, Y. Q., Malyshkin, Y., Caicedo, D. A. Martinez, McDonald, K. T., McKeown, R. D., Mitchell, I., Mooney, M., Nakajima, Y., Napolitano, J., Naumov, D., Naumova, E., Ngai, H. Y., Ning, Z., Ochoa-Ricoux, J. P., Olshevskiy, A., Pan, H. -R., Park, J., Patton, S., Pec, V., Peng, J. C., Pinsky, L., Pun, C. S. J., Qi, F. Z., Qi, M., Qian, X., Raper, N., Ren, J., Rosero, R., Roskovec, B., Ruan, X. C., Steiner, H., Sun, G. X., Sun, J. L., Tang, W., Taychenachev, D., Treskov, K., Tsang, K. V., Tull, C. E., Viaux, N., Viren, B., Vorobel, V., Wang, C. H., Wang, M., Wang, N. Y., Wang, R. G., Wang, W., Wang, X., Wang, Y. F., Wang, Z., Wang, Z. M., Wei, H. Y., Wen, L. J., Whisnant, K., White, C. G., Whitehead, L., Wise, T., Wong, H. L. H., Wong, S. C. F., Worcester, E., Wu, C. -H., Wu, Q., Wu, W. J., Xia, D. M., Xia, J. K., Xing, Z. Z., Xu, J. Y., Xu, J. L., Xu, Y., Xue, T., Yang, C. G., Yang, H., Yang, L., Yang, M. S., Yang, M. T., Ye, M., Ye, Z., Yeh, M., Young, B. L., Yu, Z. Y., Zeng, S., Zhan, L., Zhang, C., Zhang, H. H., Zhang, J. W., Zhang, Q. M., Zhang, X. T., Zhang, Y. M., Zhang, Y. X., Zhang, Z. J., Zhang, Z. Y., Zhang, Z. P., Zhao, J., Zhao, Q. W., Zhao, Y. B., Zhong, W. L., Zhou, L., Zhou, N., Zhuang, H. L., and Zou, J. H.

Subjects
High Energy Physics - Experiment, Nuclear Experiment, Physics - Instrumentation and Detectors
Abstract

A measurement of electron antineutrino oscillation by the Daya Bay Reactor Neutrino Experiment is described in detail. Six 2.9-GW$_{\rm th}$ nuclear power reactors of the Daya Bay and Ling Ao nuclear power facilities served as intense sources of $\overline{\nu}_{e}$'s. Comparison of the $\overline{\nu}_{e}$ rate and energy spectrum measured by antineutrino detectors far from the nuclear reactors ($\sim$1500-1950 m) relative to detectors near the reactors ($\sim$350-600 m) allowed a precise measurement of $\overline{\nu}_{e}$ disappearance. More than 2.5 million $\overline{\nu}_{e}$ inverse beta decay interactions were observed, based on the combination of 217 days of operation of six antineutrino detectors (Dec. 2011--Jul. 2012) with a subsequent 1013 days using the complete configuration of eight detectors (Oct. 2012--Jul. 2015). The $\overline{\nu}_{e}$ rate observed at the far detectors relative to the near detectors showed a significant deficit, $R=0.949 \pm 0.002(\mathrm{stat.}) \pm 0.002(\mathrm{syst.})$. The energy dependence of $\overline{\nu}_{e}$ disappearance showed the distinct variation predicted by neutrino oscillation. Analysis using an approximation for the three-flavor oscillation probability yielded the flavor-mixing angle $\sin^22\theta_{13}=0.0841 \pm 0.0027(\mathrm{stat.}) \pm 0.0019(\mathrm{syst.})$ and the effective neutrino mass-squared difference of $\left|{\Delta}m^2_{\mathrm{ee}}\right|=(2.50 \pm 0.06(\mathrm{stat.}) \pm 0.06(\mathrm{syst.})) \times 10^{-3}\ {\rm eV}^2$. Analysis using the exact three-flavor probability found ${\Delta}m^2_{32}=(2.45 \pm 0.06(\mathrm{stat.}) \pm 0.06(\mathrm{syst.})) \times 10^{-3}\ {\rm eV}^2$ assuming the normal neutrino mass hierarchy and ${\Delta}m^2_{32}=(-2.56 \pm 0.06(\mathrm{stat.}) \pm 0.06(\mathrm{syst.})) \times 10^{-3}\ {\rm eV}^2$ for the inverted hierarchy., Comment: 44 pages, 44 figures

Published
2016
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6. Improved Measurement of the Reactor Antineutrino Flux and Spectrum at Daya Bay

Author

An, F. P., Balantekin, A. B., Band, H. R., Bishai, M., Blyth, S., Cao, D., Cao, G. F., Cao, J., Cen, W. R., Chan, Y. L., Chang, J. F., Chang, L. C., Chang, Y., Chen, H. S., Chen, Q. Y., Chen, S. M., Chen, Y. X., Chen, Y., Cheng, J. -H., Cheng, J., Cheng, Y. P., Cheng, Z. K., Cherwinka, J. J., Chu, M. C., Chukanov, A., Cummings, J. P., de Arcos, J., Deng, Z. Y., Ding, X. F., Ding, Y. Y., Diwan, M. V., Dolgareva, M., Dove, J., Dwyer, D. A., Edwards, W. R., Gill, R., Gonchar, M., Gong, G. H., Gong, H., Grassi, M., Gu, W. Q., Guan, M. Y., Guo, L., Guo, R. P., Guo, X. H., Guo, Z., Hackenburg, R. W., Han, R., Hans, S., He, M., Heeger, K. M., Heng, Y. K., Higuera, A., Hor, Y. K., Hsiung, Y. B., Hu, B. Z., Hu, T., Hu, W., Huang, E. C., Huang, H. X., Huang, X. T., Huber, P., Huo, W., Hussain, G., Jaffe, D. E., Jaffke, P., Jen, K. L., Jetter, S., Ji, X. P., Ji, X. L., Jiao, J. B., Johnson, R. A., Jones, D., Joshi, J., Kang, L., Kettell, S. H., Kohn, S., Kramer, M., Kwan, K. K., Kwok, M. W., Kwok, T., Langford, T. J., Lau, K., Lebanowski, L., Lee, J., Lee, J. H. C., Lei, R. T., Leitner, R., Li, C., Li, D. J., Li, F., Li, G. S., Li, Q. J., Li, S., Li, S. C., Li, W. D., Li, X. N., Li, Y. F., Li, Z. B., Liang, H., Lin, C. J., Lin, G. L., Lin, S., Lin, S. K., Lin, Y. -C., Ling, J. J., Link, J. M., Littenberg, L., Littlejohn, B. R., Liu, D. W., Liu, J. L., Liu, J. C., Loh, C. W., Lu, C., Lu, H. Q., Lu, J. S., Luk, K. B., Lv, Z., Ma, Q. M., Ma, X. Y., Ma, X. B., Ma, Y. Q., Malyshkin, Y., Caicedo, D. A. Martinez, McDonald, K. T., McKeown, R. D., Mitchell, I., Mooney, M., Nakajima, Y., Napolitano, J., Naumov, D., Naumova, E., Ngai, H. Y., Ning, Z., Ochoa-Ricoux, J. P., Olshevskiy, A., Pan, H. -R., Park, J., Patton, S., Pec, V., Peng, J. C., Pinsky, L., Pun, C. S. J., Qi, F. Z., Qi, M., Qian, X., Raper, N., Ren, J., Rosero, R., Roskovec, B., Ruan, X. C., Steiner, H., Sun, G. X., Sun, J. L., Tang, W., Taychenachev, D., Treskov, K., Tsang, K. V., Tull, C. E., Viaux, N., Viren, B., Vorobel, V., Wang, C. H., Wang, M., Wang, N. Y., Wang, R. G., Wang, W., Wang, X., Wang, Y. F., Wang, Z., Wang, Z. M., Wei, H. Y., Wen, L. J., Whisnant, K., White, C. G., Whitehead, L., Wise, T., Wong, H. L. H., Wong, S. C. F., Worcester, E., Wu, C. -H., Wu, Q., Wu, W. J., Xia, D. M., Xia, J. K., Xing, Z. Z., Xu, J. Y., Xu, J. L., Xu, Y., Xue, T., Yang, C. G., Yang, H., Yang, L., Yang, M. S., Yang, M. T., Ye, M., Ye, Z., Yeh, M., Young, B. L., Yu, Z. Y., Zeng, S., Zhan, L., Zhang, C., Zhang, H. H., Zhang, J. W., Zhang, Q. M., Zhang, X. T., Zhang, Y. M., Zhang, Y. X., Zhang, Z. J., Zhang, Z. Y., Zhang, Z. P., Zhao, J., Zhao, Q. W., Zhao, Y. B., Zhong, W. L., Zhou, L., Zhou, N., Zhuang, H. L., and Zou, J. H.

Subjects
High Energy Physics - Experiment, Nuclear Experiment, Physics - Instrumentation and Detectors
Abstract

A new measurement of the reactor antineutrino flux and energy spectrum by the Daya Bay reactor neutrino experiment is reported. The antineutrinos were generated by six 2.9~GW$_{\mathrm{th}}$ nuclear reactors and detected by eight antineutrino detectors deployed in two near (560~m and 600~m flux-weighted baselines) and one far (1640~m flux-weighted baseline) underground experimental halls. With 621 days of data, more than 1.2 million inverse beta decay (IBD) candidates were detected. The IBD yield in the eight detectors was measured, and the ratio of measured to predicted flux was found to be $0.946\pm0.020$ ($0.992\pm0.021$) for the Huber+Mueller (ILL+Vogel) model. A 2.9~$\sigma$ deviation was found in the measured IBD positron energy spectrum compared to the predictions. In particular, an excess of events in the region of 4-6~MeV was found in the measured spectrum, with a local significance of 4.4~$\sigma$. A reactor antineutrino spectrum weighted by the IBD cross section is extracted for model-independent predictions., Comment: version published in Chinese Physics C

Published
2016
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7. Measurement of the Reactor Antineutrino Flux and Spectrum at Daya Bay

Author

Daya Bay Collaboration, An, F. P., Balantekin, A. B., Band, H. R., Bishai, M., Blyth, S., Butorov, I., Cao, D., Cao, G. F., Cao, J., Cen, W. R., Chan, Y. L., Chang, J. F., Chang, L. C., Chang, Y., Chen, H. S., Chen, Q. Y., Chen, S. M., Chen, Y. X., Chen, Y., Cheng, J. H., Cheng, J., Cheng, Y. P., Cherwinka, J. J., Chu, M. C., Cummings, J. P., de Arcos, J., Deng, Z. Y., Ding, X. F., Ding, Y. Y., Diwan, M. V., Dove, J., Draeger, E., Dwyer, D. A., Edwards, W. R., Ely, S. R., Gill, R., Gonchar, M., Gong, G. H., Gong, H., Grassi, M., Gu, W. Q., Guan, M. Y., Guo, L., Guo, X. H., Hackenburg, R. W., Han, R., Hans, S., He, M., Heeger, K. M., Heng, Y. K., Higuera, A., Hor, Y. K., Hsiung, Y. B., Hu, B. Z., Hu, L. M., Hu, L. J., Hu, T., Hu, W., Huang, E. C., Huang, H. X., Huang, X. T., Huber, P., Hussain, G., Jaffe, D. E., Jaffke, P., Jen, K. L., Jetter, S., Ji, X. P., Ji, X. L., Jiao, J. B., Johnson, R. A., Kang, L., Kettell, S. H., Kohn, S., Kramer, M., Kwan, K. K., Kwok, M. W., Kwok, T., Langford, T. J., Lau, K., Lebanowski, L., Lee, J., Lei, R. T., Leitner, R., Leung, K. Y., Leung, J. K. C., Lewis, C. A., Li, D. J., Li, F., Li, G. S., Li, Q. J., 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, P. Y., Lin, S. K., Ling, J. J., Link, J. M., Littenberg, L., Littlejohn, B. R., Liu, D. W., Liu, H., Liu, J. L., Liu, J. C., Liu, S. S., Lu, C., Lu, H. Q., Lu, J. S., Luk, K. B., Ma, Q. M., Ma, X. Y., Ma, X. B., Ma, Y. Q., Caicedo, D. A. Martinez, McDonald, K. T., McKeown, R. D., Meng, Y., Mitchell, I., Kebwaro, J. Monari, Nakajima, Y., Napolitano, J., Naumov, D., Naumova, E., Ngai, H. Y., Ning, Z., Ochoa-Ricoux, J. P., Olshevski, A., Pan, H. -R., Park, J., Patton, S., Pec, V., Peng, J. C., Piilonen, L. E., Pinsky, L., Pun, C. S. J., Qi, F. Z., Qi, M., Qian, X., Raper, N., Ren, B., Ren, J., Rosero, R., Roskovec, B., Ruan, X. C., Shao, B. B., Steiner, H., Sun, G. X., Sun, J. L., Tang, W., Taychenachev, D., Tsang, K. V., Tull, C. E., Tung, Y. C., Viaux, N., Viren, B., Vorobel, V., Wang, C. H., Wang, M., Wang, N. Y., Wang, R. G., Wang, W., Wang, W. W., Wang, X., Wang, Y. F., Wang, Z., Wang, Z. M., Wei, H. Y., Wen, L. J., Whisnant, K., White, C. G., Whitehead, L., Wise, T., Wong, H. L. H., Wong, S. C. F., Worcester, E., Wu, Q., Xia, D. M., Xia, J. K., Xia, X., Xing, Z. Z., Xu, J. Y., Xu, J. L., Xu, J., Xu, Y., Xue, T., Yan, J., Yang, C. G., Yang, L., Yang, M. S., Yang, M. T., Ye, M., Yeh, M., Young, B. L., Yu, G. Y., Yu, Z. Y., Zang, S. L., Zhan, L., Zhang, C., Zhang, H. H., Zhang, J. W., Zhang, Q. M., Zhang, Y. M., Zhang, Y. X., Zhang, Z. J., Zhang, Z. Y., Zhang, Z. P., Zhao, J., Zhao, Q. W., Zhao, Y. F., Zhao, Y. B., Zheng, L., Zhong, W. L., Zhou, L., Zhou, N., Zhuang, H. L., and Zou, J. H.

Subjects
High Energy Physics - Experiment, Nuclear Experiment, Physics - Instrumentation and Detectors
Abstract

This Letter reports a measurement of the flux and energy spectrum of electron antineutrinos from six 2.9~GW$_{th}$ nuclear reactors with six detectors deployed in two near (effective baselines 512~m and 561~m) and one far (1,579~m) underground experimental halls in the Daya Bay experiment. Using 217 days of data, 296,721 and 41,589 inverse beta decay (IBD) candidates were detected in the near and far halls, respectively. The measured IBD yield is (1.55 $\pm$ 0.04) $\times$ 10$^{-18}$~cm$^2$/GW/day or (5.92 $\pm$ 0.14) $\times$ 10$^{-43}$~cm$^2$/fission. This flux measurement is consistent with previous short-baseline reactor antineutrino experiments and is $0.946\pm0.022$ ($0.991\pm0.023$) relative to the flux predicted with the Huber+Mueller (ILL+Vogel) fissile antineutrino model. The measured IBD positron energy spectrum deviates from both spectral predictions by more than 2$\sigma$ over the full energy range with a local significance of up to $\sim$4$\sigma$ between 4-6 MeV. A reactor antineutrino spectrum of IBD reactions is extracted from the measured positron energy spectrum for model-independent predictions.

Published
2015
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8. Generalized perturbations in neutrino mixing

Author

Liao, Jiajun, Marfatia, D., and Whisnant, K.

Subjects
High Energy Physics - Phenomenology, High Energy Physics - Experiment, Nuclear Experiment, Nuclear Theory
Abstract

We derive expressions for the neutrino mixing parameters that result from complex perturbations on (1) the Majorana neutrino mass matrix (in the basis of charged lepton mass eigenstates) and on (2) the charged lepton mass matrix, for arbitrary initial (unperturbed) mixing matrices. In the first case, we find that the phases of the elements of the perturbation matrix, and the initial values of the Dirac and Majorana phases, strongly impact the leading order corrections to the neutrino mixing parameters and phases. For experimentally compatible scenarios wherein the initial neutrino mass matrix has $\mu-\tau$ symmetry, we find that the Dirac phase can take any value under small perturbations. Similarly, in the second case, perturbations to the charged lepton mass matrix can generate large corrections to the mixing angles and phases of the PMNS matrix. As an illustration of our generalized procedure, we apply it to a situation in which nonstandard scalar and nonstandard vector interactions simultaneously affect neutrino oscillations., Comment: 26 pages, 3 figures, 1 table. Published version

Published
2015
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9. A new measurement of antineutrino oscillation with the full detector configuration at Daya Bay

Author

Daya Bay Collaboration, An, F. P., Balantekin, A. B., Band, H. R., Bishai, M., Blyth, S., Butorov, I., Cao, G. F., Cao, J., Cen, W. R., Chan, Y. L., Chang, J. F., Chang, L. C., Chang, Y., Chen, H. S., Chen, Q. Y., Chen, S. M., Chen, Y. X., Chen, Y., Cheng, J. H., Cheng, J., Cheng, Y. P., Cherwinka, J. J., Chu, M. C., Cummings, J. P., de Arcos, J., Deng, Z. Y., Ding, X. F., Ding, Y. Y., Diwan, M. V., Draeger, E., Dwyer, D. A., Edwards, W. R., Ely, S. R., Gill, R., Gonchar, M., Gong, G. H., Gong, H., Grassi, M., Gu, W. Q., Guan, M. Y., Guo, L., Guo, X. H., Hackenburg, R. W., Han, R., Hans, S., He, M., Heeger, K. M., Heng, Y. K., Hor, Y. K., Hsiung, Y. B., Hu, B. Z., Hu, L. M., Hu, L. J., Hu, T., Hu, W., Huang, E. C., Huang, H. X., Huang, X. T., Huber, P., Hussain, G., Jaffe, D. E., Jaffke, P., Jen, K. L., Jetter, S., Ji, X. P., Ji, X. L., Jiao, J. B., Johnson, R. A., Kang, L., Kettell, S. H., Kramer, M., Kwan, K. K., Kwok, M. W., Kwok, T., Langford, T. J., Lau, K., Lebanowski, L., Lee, J., Lei, R. T., Leitner, R., Leung, A., Leung, J. K. C., Lewis, C. A., Li, D. J., Li, F., Li, G. S., Li, Q. J., 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, P. Y., Lin, S. K., Ling, J. J., Link, J. M., Littenberg, L., Littlejohn, B. R., Liu, D. W., Liu, H., Liu, J. L., Liu, J. C., Liu, S. S., Lu, C., Lu, H. Q., Lu, J. S., Luk, K. B., Ma, Q. M., Ma, X. Y., Ma, X. B., Ma, Y. Q., McDonald, K. T., McKeown, R. D., Meng, Y., Mitchell, I., Kebwaro, J. Monari, Nakajima, Y., Napolitano, J., Naumov, D., Naumova, E., Ngai, H. Y., Ning, Z., Ochoa-Ricoux, J. P., Olshevski, A., Patton, S., Pec, V., Peng, J. C., Piilonen, L. E., Pinsky, L., Pun, C. S. J., Qi, F. Z., Qi, M., Qian, X., Raper, N., Ren, B., Ren, J., Rosero, R., Roskovec, B., Ruan, X. C., Shao, B. B., Steiner, H., Sun, G. X., Sun, J. L., Tang, W., Themann, H., Tsang, K. V., Tull, C. E., Tung, Y. C., Viaux, N., Viren, B., Vorobel, V., Wang, C. H., Wang, M., Wang, N. Y., Wang, R. G., Wang, W., Wang, W. W., Wang, X., Wang, Y. F., Wang, Z., Wang, Z. M., Wei, H. Y., Wen, L. J., Whisnant, K., White, C. G., Whitehead, L., Wise, T., Wong, H. L. H., Wong, S. C. F., Worcester, E., Wu, Q., Xia, D. M., Xia, J. K., Xia, X., Xing, Z. Z., Xu, J. Y., Xu, J. L., Xu, J., Xu, Y., Xue, T., Yan, J., Yang, C. G., Yang, L., Yang, M. S., Yang, M. T., Ye, M., Yeh, M., Yeh, Y. S., Young, B. L., Yu, G. Y., Yu, Z. Y., Zang, S. L., Zhan, L., Zhang, C., Zhang, H. H., Zhang, J. W., Zhang, Q. M., Zhang, Y. M., Zhang, Y. X., Zhang, Z. J., Zhang, Z. Y., Zhang, Z. P., Zhao, J., Zhao, Q. W., Zhao, Y. F., Zhao, Y. B., Zheng, L., Zhong, W. L., Zhou, L., Zhou, N., Zhuang, H. L., and Zou, J. H.

Subjects
High Energy Physics - Experiment, Nuclear Experiment, Physics - Instrumentation and Detectors
Abstract

We report a new measurement of electron antineutrino disappearance using the fully-constructed Daya Bay Reactor Neutrino Experiment. The final two of eight antineutrino detectors were installed in the summer of 2012. Including the 404 days of data collected from October 2012 to November 2013 resulted in a total exposure of 6.9$\times$10$^5$ GW$_{\rm th}$-ton-days, a 3.6 times increase over our previous results. Improvements in energy calibration limited variations between detectors to 0.2%. Removal of six $^{241}$Am-$^{13}$C radioactive calibration sources reduced the background by a factor of two for the detectors in the experimental hall furthest from the reactors. Direct prediction of the antineutrino signal in the far detectors based on the measurements in the near detectors explicitly minimized the dependence of the measurement on models of reactor antineutrino emission. The uncertainties in our estimates of $\sin^{2}2\theta_{13}$ and $|\Delta m^2_{ee}|$ were halved as a result of these improvements. Analysis of the relative antineutrino rates and energy spectra between detectors gave $\sin^{2}2\theta_{13} = 0.084\pm0.005$ and $|\Delta m^{2}_{ee}|= (2.42\pm0.11) \times 10^{-3}$ eV$^2$ in the three-neutrino framework., Comment: Updated to match final published version

Published
2015
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10. Spectral measurement of electron antineutrino oscillation amplitude and frequency at Daya Bay

Author

Daya Bay Collaboration, An, F. P., Balantekin, A. B., Band, H. R., Beriguete, W., Bishai, M., Blyth, S., Brown, R. L., Butorov, I., Cao, G. F., Cao, J., Carr, R., Chan, Y. L., Chang, J. F., Chang, Y., Chasman, C., Chen, H. S., Chen, H. Y., Chen, S. J., Chen, S. M., Chen, X. C., Chen, X. H., Chen, Y., Chen, Y. X., Cheng, Y. P., Cherwinka, J. J., Chu, M. C., Cummings, J. P., de Arcos, J., Deng, Z. Y., Ding, Y. Y., Diwan, M. V., Draeger, E., Du, X. F., Dwyer, D. A., Edwards, W. R., Ely, S. R., Fu, J. Y., Ge, L. Q., Gill, R., Gonchar, M., Gong, G. H., Gong, H., Gornushkin, Y. A., Gu, W. Q., Guan, M. Y., Guo, X. H., Hackenburg, R. W., Hahn, R. L., Han, G. H., Hans, S., He, M., Heeger, K. M., Heng, Y. K., Hinrichs, P., Hor, yk., Hsiung, Y. B., Hu, B. Z., Hu, L. J., Hu, L. M., Hu, T., Hu, W., Huang, E. C., Huang, H. X., Huang, H. Z., Huang, X. T., Huber, P., Hussain, G., Isvan, Z., Jaffe, D. E., Jaffke, P., Jetter, S., Ji, X. L., Ji, X. P., Jiang, H. J., Jiao, J. B., Johnson, R. A., Kang, L., Kettell, S. H., Kramer, M., Kwan, K. K., Kwok, M. W., Kwok, T., Lai, W. C., Lai, W. H., Lau, K., Lebanowski, L., Lee, J., Lei, R. T., Leitner, R., Leung, A., Leung, J. K. C., Lewis, C. A., Li, D. J., Li, F., Li, G. S., Li, Q. J., 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. K., Lin, Y. C., Ling, J. J., Link, J. M., Littenberg, L., Littlejohn, B. R., Liu, D. W., Liu, H., Liu, J. C., Liu, J. L., Liu, S. S., Liu, Y. B., Lu, C., Lu, H. Q., Luk, K. B., Ma, Q. M., Ma, X. B., Ma, X. Y., Ma, Y. Q., McDonald, K. T., McFarlane, M. C., McKeown, R. D., Meng, Y., Mitchell, I., Nakajima, Y., Napolitano, J., Naumov, D., Naumova, E., Nemchenok, I., Ngai, H. Y., Ngai, W. K., Ning, Z., Ochoa-Ricoux, J. P., Olshevski, A., Patton, S., Pec, V., Peng, J. C., Piilonen, L. E., Pinsky, L., Pun, C. S. J., Qi, F. Z., Qi, M., Qian, X., Raper, N., Ren, B., Ren, J., Rosero, R., Roskovec, B., Ruan, X. C., Shao, B. B., Steiner, H., Sun, G. X., Sun, J. L., Tam, Y. H., Tanaka, H. K., Tang, X., Themann, H., Trentalange, S., Tsai, O., Tsang, K. V., Tsang, R. H. M., Tull, C. E., Tung, Y. C., Viren, B., Vorobel, V., Wang, C. H., Wang, L. S., Wang, L. Y., Wang, L. Z., Wang, M., Wang, N. Y., Wang, R. G., Wang, W., Wang, W. W., Wang, X., Wang, Y. F., Wang, Z., Wang, Z. M., Webber, D. M., Wei, H., Wei, Y. D., Wen, L. J., Whisnant, K., White, C. G., Whitehead, L., Wise, T., Wong, H. L. H., Wong, S. C. F., Worcester, E., Wu, Q., Xia, D. M., Xia, J. K., Xia, X., Xing, Z. Z., Xu, J., Xu, J. L., Xu, J. Y., Xu, Y., Xue, T., Yan, J., Yang, C. G., Yang, L., Yang, M. S., Ye, M., Yeh, M., Yeh, Y. S., Young, B. L., Yu, G. Y., Yu, J. Y., Yu, Z. Y., Zang, S. L., Zhan, L., Zhang, C., Zhang, F. H., Zhang, J. W., Zhang, Q. M., Zhang, S. H., Zhang, Y. C., Zhang, Y. H., Zhang, Y. M., Zhang, Y. X., Zhang, Z. J., Zhang, Z. P., Zhang, Z. Y., Zhao, J., Zhao, Q. W., Zhao, Y. B., Zheng, L., Zhong, W. L., Zhou, L., Zhou, Z. Y., Zhuang, H. L., and Zou, J. H.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

A measurement of the energy dependence of antineutrino disappearance at the Daya Bay Reactor Neutrino Experiment is reported. Electron antineutrinos ($\overline{\nu}_{e}$) from six $2.9$ GW$_{\rm th}$ reactors were detected with six detectors deployed in two near (effective baselines 512 m and 561 m) and one far (1579 m) underground experimental halls. Using 217 days of data, 41589 (203809 and 92912) antineutrino candidates were detected in the far hall (near halls). An improved measurement of the oscillation amplitude $\sin^{2}2\theta_{13} = 0.090^{+0.008}_{-0.009} $ and the first direct measurement of the $\overline{\nu}_{e}$ mass-squared difference $|\Delta m^{2}_{ee}|= (2.59_{-0.20}^{+0.19}) \times 10^{-3}\ {\rm eV}^2 $ is obtained using the observed $\overline{\nu}_{e}$ rates and energy spectra in a three-neutrino framework. This value of $|\Delta m^{2}_{ee}|$ is consistent with $|\Delta m^{2}_{\mu\mu}|$ measured by muon neutrino disappearance, supporting the three-flavor oscillation model., Comment: As accepted for publication by Phys. Rev. Lett. including ancillary table

Published
2013
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11. Improved Measurement of Electron Antineutrino Disappearance at Daya Bay

Author

Daya Bay Collaboration, An, F. P., An, Q., Bai, J. Z., Balantekin, A. B., Band, H. R., Beriguete, W., Bishai, M., Blyth, S., Brown, R. L., Cao, G. F., Cao, J., Carr, R., Chan, W. T., Chang, J. F., Chang, Y., Chasman, C., Chen, H. S., Chen, H. Y., Chen, S. J., Chen, S. M., Chen, X. C., Chen, X. H., Chen, X. S., Chen, Y., Chen, Y. X., Cherwinka, J. J., Chu, M. C., Cummings, J. P., Deng, Z. Y., Ding, Y. Y., Diwan, M. V., Draeger, E., Du, X. F., Dwyer, D., Edwards, W. R., Ely, S. R., Fang, S. D., Fu, J. Y., Fu, Z. W., Ge, L. Q., Gill, R. L., Gonchar, M., Gong, G. H., Gong, H., Gornushkin, Y. A., Gu, W. Q., Guan, M. Y., Guo, X. H., Hackenburg, R. W., Hahn, R. L., Hans, S., Hao, H. F., He, M., He, Q., Heeger, K. M., Heng, Y. K., Hinrichs, P., Hor, Y. K., Hsiung, Y. B., Hu, B. Z., Hu, T., Huang, H. X., Huang, H. Z., Huang, X. T., Huber, P., Issakov, V., Isvan, Z., Jaffe, D. E., Jetter, S., Ji, X. L., Ji, X. P., Jiang, H. J., Jiao, J. B., Johnson, R. A., Kang, L., Kettell, S. H., Kramer, M., Kwan, K. K., Kwok, M. W., Kwok, T., Lai, C. Y., Lai, W. C., Lai, W. H., Lau, K., Lebanowski, L., Lee, J., Lei, R. T., Leitner, R., Leung, J. K. C., Leung, K. Y., Lewis, C. A., Li, F., Li, G. S., Li, Q. J., Li, W. D., Li, X. B., Li, X. N., Li, X. Q., Li, Y., Li, Z. B., Liang, H., Lin, C. J., Lin, G. L., Lin, S. K., Lin, Y. C., Ling, J. J., Link, J. M., Littenberg, L., Littlejohn, B. R., Liu, D. W., Liu, J. C., Liu, J. L., Liu, Y. B., Lu, C., Lu, H. Q., Luk, A., Luk, K. B., Ma, Q. M., Ma, X. B., Ma, X. Y., Ma, Y. Q., McDonald, K. T., McFarlane, M. C., McKeown, R. D., Meng, Y., Mohapatra, D., Nakajima, Y., Napolitano, J., Naumov, D., Nemchenok, I., Ngai, H. Y., Ngai, W. K., Nie, Y. B., Ning, Z., Ochoa-Ricoux, J. P., Olshevski, A., Patton, S., Pec, V., Peng, J. C., Piilonen, L. E., Pinsky, L., Pun, C. S. J., Qi, F. Z., Qi, M., Qian, X., Raper, N., Ren, J., Rosero, R., Roskovec, B., Ruan, X. C., Shao, B. B., Shih, K., Steiner, H., Sun, G. X., Sun, J. L., Tagg, N., Tam, Y. H., Tanaka, H. K., Tang, X., Themann, H., Torun, Y., Trentalange, S., Tsai, O., Tsang, K. V., Tsang, R. H. M., Tull, C. E., Tung, Y. C., Viren, B., Vorobel, V., Wang, C. H., Wang, L. S., Wang, L. Y., Wang, L. Z., Wang, M., Wang, N. Y., Wang, R. G., Wang, W., Wang, X., Wang, Y. F., Wang, Z., Wang, Z. M., Webber, D. M., Wei, H. Y., Wei, Y. D., Wen, L. J., Whisnant, K., White, C. G., Whitehead, L., Williamson, Y., Wise, T., Wong, H. L. H., Worcester, E. T., Wu, F. F., Wu, Q., Xi, J. B., Xia, D. M., Xing, Z. Z., Xu, J., Xu, J. L., Xu, Y., Xue, T., Yang, C. G., Yang, L., Ye, M., Yeh, M., Yeh, Y. S., Young, B. L., Yu, Z. Y., Zhan, L., Zhang, C., Zhang, F. H., Zhang, J. W., Zhang, Q. M., Zhang, S. H., Zhang, Y. C., Zhang, Y. H., Zhang, Y. X., Zhang, Z. J., Zhang, Z. P., Zhang, Z. Y., Zhao, J., Zhao, Q. W., Zhao, Y. B., Zheng, L., Zhong, W. L., Zhou, L., Zhou, Z. Y., Zhuang, H. L., and Zou, J. H.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

We report an improved measurement of the neutrino mixing angle $\theta_{13}$ from the Daya Bay Reactor Neutrino Experiment. We exclude a zero value for $\sin^22\theta_{13}$ with a significance of 7.7 standard deviations. Electron antineutrinos from six reactors of 2.9 GW$_{\rm th}$ were detected in six antineutrino detectors deployed in two near (flux-weighted baselines of 470 m and 576 m) and one far (1648 m) underground experimental halls. Using 139 days of data, 28909 (205308) electron antineutrino candidates were detected at the far hall (near halls). The ratio of the observed to the expected number of antineutrinos assuming no oscillations at the far hall is $0.944\pm 0.007({\rm stat.}) \pm 0.003({\rm syst.})$. An analysis of the relative rates in six detectors finds $\sin^22\theta_{13}=0.089\pm 0.010({\rm stat.})\pm0.005({\rm syst.})$ in a three-neutrino framework., Comment: 21 pages, 24 figures. Submitted to and accepted by Chinese Physics C. Two typos were corrected. Description improved

Published
2012
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12. A side-by-side comparison of Daya Bay antineutrino detectors

Author

Daya Bay Collaboration, An, F. P., An, Q., Bai, J. Z., Balantekin, A. B., Band, H. R., Beriguete, W., Bishai, M., Blyth, S., Brown, R. L., Cao, G. F., Cao, J., Carr, R., Chang, J. F., Chang, Y., Chasman, C., Chen, H. S., Chen, S. J., Chen, S. M., Chen, X. C., Chen, X. H., Chen, X. S., Chen, Y., Cherwinka, J. J., Chu, M. C., Cummings, J. P., Deng, Z. Y., Ding, Y. Y., Diwan, M. V., Draeger, E., Du, X. F., Dwyer, D., Edwards, W. R., Ely, S. R., Fang, S. D., Fu, J. Y., Fu, Z. W., Ge, L. Q., Gill, R. L., Gonchar, M., Gong, G. H., Gong, H., Gornushkin, Y. A., Greenler, L. S., Gu, W. Q., Guan, M. Y., Guo, X. H., Hackenburg, R. W., Hahn, R. L., Hans, S., Hao, H. F., He, M., He, Q., He, W. S., Heeger, K. M., Heng, Y. K., Hinrichs, P., Ho, T. H., Hor, Y. K., Hsiung, Y. B., Hu, B. Z., Hu, T., Huang, H. X., Huang, H. Z., Huang, P. W., Huang, X., Huang, X. T., Huber, P., Jaffe, D. E., Jetter, S., Ji, X. L., Ji, X. P., Jiang, H. J., Jiang, W. Q., Jiao, J. B., Johnson, R. A., Kang, L., Kettell, S. H., Kramer, M., Kwan, K. K., Kwok, M. W., Kwok, T., Lai, C. Y., Lai, W. C., Lai, W. H., Lau, K., Lebanowski, L., Lee, M. K. P., Leitner, R., Leung, J. K. C., Leung, K. Y., Lewis, C. A., Li, F., Li, G. S., Li, J., Li, Q. J., Li, S. F., Li, W. D., Li, X. B., Li, X. N., Li, X. Q., Li, Y., Li, Z. B., Liang, H., Lin, C. J., Lin, G. L., Lin, S. K., Lin, S. X., Lin, Y. C., Ling, J. J., Link, J. M., Littenberg, L., Littlejohn, B. R., Liu, B. J., Liu, D. W., Liu, J. C., Liu, J. L., Liu, S., Liu, X., Liu, Y. B., Lu, C., Lu, H. Q., Luk, A., Luk, K. B., Luo, X. L., Ma, L. H., Ma, Q. M., Ma, X. Y., Ma, Y. Q., Mayes, B., McDonald, K. T., McFarlane, M. C., McKeown, R. D., Meng, Y., Mohapatra, D., Nakajima, Y., Napolitano, J., Naumov, D., Nemchenok, I., Newsom, C., Ngai, H. Y., Ngai, W. K., Nie, Y. B., Ning, Z., Ochoa-Ricoux, J. P., Olshevski, A., Pagac, A., Patton, S., Pec, V., Peng, J. C., Piilonen, L. E., Pinsky, L., Pun, C. S. J., Qi, F. Z., Qi, M., Qian, X., Rosero, R., Roskovec, B., Ruan, X. C., Seilhan, B., Shao, B. B., Shih, K., Steiner, H., Stoler, P., Sun, G. X., Sun, J. L., Tam, Y. H., Tanaka, H. K., Tang, X., Torun, Y., Trentalange, S., Tsai, O., Tsang, K. V., Tsang, R. H. M., Tull, C., Viren, B., Vorobel, V., Wang, C. H., Wang, L. S., Wang, L. Y., Wang, M., Wang, N. Y., Wang, R. G., Wang, W., Wang, X., Wang, Y. F., Wang, Z., Wang, Z. M., Webber, D. M., Wei, Y. D., Wen, L. J., Wenman, D. L., Whisnant, K., White, C. G., Whitehead, L., Wilhelmi, J., Wise, T., Wong, H. L. H., Wong, J., Wu, F. F., Wu, Q., Xi, J. B., Xia, D. M., Xiao, Q., Xing, Z. Z., Xu, G., Xu, J., Xu, J. L., Xu, Y., Xue, T., Yang, C. G., Yang, L., Ye, M., Yeh, M., Yeh, Y. S., Young, B. L., Yu, Z. Y., Zhan, L., Zhang, C., Zhang, F. H., Zhang, J. W., Zhang, Q. M., Zhang, S. H., Zhang, Y. C., Zhang, Y. H., Zhang, Y. X., Zhang, Z. J., Zhang, Z. P., Zhang, Z. Y., Zhao, H., Zhao, J., Zhao, Q. W., Zhao, Y. B., Zheng, L., Zhong, W. L., Zhou, L., Zhou, Y. Z., Zhou, Z. Y., Zhuang, H. L., and Zou, J. H.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment, Nuclear Experiment
Abstract

The Daya Bay Reactor Neutrino Experiment is designed to determine precisely the neutrino mixing angle $\theta_{13}$ with a sensitivity better than 0.01 in the parameter sin$^22\theta_{13}$ at the 90% confidence level. To achieve this goal, the collaboration will build eight functionally identical antineutrino detectors. The first two detectors have been constructed, installed and commissioned in Experimental Hall 1, with steady data-taking beginning September 23, 2011. A comparison of the data collected over the subsequent three months indicates that the detectors are functionally identical, and that detector-related systematic uncertainties exceed requirements., Comment: 24 pages, 36 figures

Published
2012
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13. Confronting mass-varying neutrinos with MiniBooNE

Author

Barger, V., Marfatia, D., and Whisnant, K.

Subjects
High Energy Physics - Phenomenology, Astrophysics, High Energy Physics - Experiment, Nuclear Experiment, Nuclear Theory
Abstract

We study the proposal that mass-varying neutrinos could provide an explanation for the LSND signal for \bar\nu_mu to \bar\nu_e oscillations. We first point out that all positive oscillation signals occur in matter and that three active mass-varying neutrinos are insufficient to describe all existing neutrino data including LSND. We then examine the possibility that a model with four mass-varying neutrinos (three active and one sterile) can explain the LSND effect and remain consistent with all other neutrino data. We find that such models with a 3+1 mass structure in the neutrino sector may explain the LSND data and a null MiniBooNE result for 0.10 < \sin^2 2\theta_x < 0.30. Predictions of the model include a null result at Double-CHOOZ, but positive signals for underground reactor experiments and for \nu_\mu to \nu_e oscillations in long-baseline experiments., Comment: 22 pages, 3 figures, 1 table. Comment added about recent MINOS data

Published
2005
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14. Testing the LMA solution with solar neutrinos independently of solar models

Author

Barger, V., Marfatia, D., and Whisnant, K.

Subjects
High Energy Physics - Phenomenology, Astrophysics, High Energy Physics - Experiment, Nuclear Experiment, Nuclear Theory
Abstract

We perform a comparative study of two methods of determining the survival probabilities of low, intermediate, and high energy solar neutrinos that emphasizes the general agreement between the Large Mixing Angle (LMA) solution and extant solar neutrino data. The first analysis is oscillation parameter-independent and the second analysis involves an approximate calculation of the survival probabilities in the three energy ranges that depends only on oscillation parameters. We show that future experiments like BOREXino, CLEAN, Heron, LENS and MOON, that measure $pp$ and $^7$Be neutrinos, will facilitate a stringent test of the LMA solution independently of the Standard Solar Model (SSM), without recourse to earth-matter effects. Throughout, we describe the role of SSM assumptions on our results. If the LMA solution passes the test without needing to be modified, it may be possible to establish that $\theta_x$ is nonzero at more than $2\sigma$ assuming the SSM prediction for the $pp$ flux is correct., Comment: Final SNO salt-phase data included in analysis. Version to appear in PLB

Published
2005
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15. Progress in the physics of massive neutrinos

Author

Barger, V., Marfatia, D., and Whisnant, K.

Subjects
High Energy Physics - Phenomenology, Astrophysics, High Energy Physics - Experiment, Nuclear Experiment, Nuclear Theory
Abstract

The current status of the physics of massive neutrinos is reviewed with a forward-looking emphasis. The article begins with the general phenomenology of neutrino oscillations in vacuum and matter and documents the experimental evidence for oscillations of solar, reactor, atmospheric and accelerator neutrinos. Both active and sterile oscillation possibilities are considered. The impact of cosmology (BBN, CMB, leptogenesis) and astrophysics (supernovae, highest energy cosmic rays) on neutrino observables and vice versa, is evaluated. The predictions of grand unified, radiative and other models of neutrino mass are discussed. Ways of determining the unknown parameters of three-neutrino oscillations are assessed, taking into account eight-fold degeneracies in parameters that yield the same oscillation probabilities, as well as ways to determine the absolute neutrino mass scale (from beta-decay, neutrinoless double-beta decay, large scale structure and Z-bursts). Critical unknowns at present are the amplitude of \nu_\mu to \nu_e oscillations and the hierarchy of the neutrino mass spectrum; the detection of CP violation in the neutrino sector depends on these and on an unknown phase. The estimated neutrino parameter sensitivities at future facilities (reactors, superbeams, neutrino factories) are given. The overall agenda of a future neutrino physics program to construct a bottom-up understanding of the lepton sector is presented., Comment: 111 pages, 35 figures. Updated

Published
2003
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16. Imprint of SNO neutral current data on the solar neutrino problem

Author

Barger, V., Marfatia, D., Whisnant, K., and Wood, B. P.

Subjects
High Energy Physics - Phenomenology, Astrophysics, High Energy Physics - Experiment, Nuclear Experiment
Abstract

We perform a global analysis in the framework of two active neutrino oscillations of all solar neutrino data, including the recent SNO day and night spectra (comprised of the charged current (CC), elastic scattering (ES) and neutral current (NC) events), the Super-Kamiokande (SK) day and night spectra (from 1496 days) and the updated SAGE results. We find that the Large Mixing Angle (LMA) solution is selected at the 99% C.L.; the best-fit parameters are \Delta m^2=5.6 \times 10^{-5} eV^2 and \theta=32^{\circ}. No solutions with \theta\geq \pi/4 are allowed at the 5\sigma C.L. Oscillations to a pure sterile state are excluded at 5.3\sigma, but a sizeable sterile neutrino component could still be present in the solar flux., Comment: Version to appear in PLB

Published
2002
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17. Unknowns after the SNO Charged-Current Measurement

Author

Barger, V., Marfatia, D., and Whisnant, K.

Subjects
High Energy Physics - Phenomenology, High Energy Physics - Experiment, Nuclear Experiment
Abstract

We perform a model-independent analysis of solar neutrino flux rates including the recent charged-current measurement at the Sudbury Neutrino Observatory (SNO). We derive a universal sum rule involving SNO and SuperKamiokande rates, and show that the SNO neutral-current measurement can not fix the fraction of solar $\nu_e$ oscillating to sterile neutrinos. The large uncertainty in the SSM $^8$B flux impedes a determination of the sterile neutrino fraction., Comment: Version to appear in PRL; includes analysis with anticipated SNO NC measurement

Published
2001
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18. First Measurement of High-Energy Reactor Antineutrinos at Daya Bay

Author

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. 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., and Zou, J. H.

Subjects
High Energy Physics - Experiment (hep-ex), FOS: Physical sciences, General Physics and Astronomy, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment, High Energy Physics - Experiment, Physics::Geophysics
Abstract

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-$Q_{\beta}$ isotopes in commercial reactors., Comment: 7 pages, 4 figures, accepted by Physical Review Letters

Published
2022

19. Extraction of the $^{235}$U and $^{239}$Pu Antineutrino Spectra at Daya Bay

Author

Daya Bay Collaboration, Adey, D., An, F. P., Balantekin, A. B., Band, H. R., Bishai, M., Blyth, S., Cao, D., Cao, G. F., Cao, J., Chang, J. F., Chang, Y., Chen, H. S., Chen, S. M., Chen, Y., Chen, Y. X., Cheng, J., Cheng, Z. K., Cherwinka, J. J., Chu, M. C., Chukanov, A., Cummings, J. P., Dash, N., Deng, F. S., Ding, Y. Y., Diwan, M. V., Dohnal, T., Dove, J., Dvorak, M., Dwyer, D. A., 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., Higuera, A., Hor, Y. K., Hsiung, Y. B., Hu, B. Z., Hu, J. R., Hu, T., Hu, Z. J., Huang, H. X., 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., Koerner, L. W., Kohn, S., Kramer, M., Langford, T. J., Lee, J., Lee, J. H. C., Lei, R. T., Leitner, R., Leung, J. K. C., Li, C., Li, F., Li, H. L., Li, Q. J., Li, S., Li, S. C., Li, S. J., 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., Lin, S. K., Ling, J. J., Link, J. M., Littenberg, L., Littlejohn, B. R., Liu, J. C., Liu, J. L., Liu, Y., Liu, Y. H., Lu, C., Lu, H. Q., Lu, J. S., Luk, K. B., Ma, X. B., Ma, X. Y., Ma, Y. Q., Marshall, C., Caicedo, D. A. Martinez, McDonald, K. T., McKeown, R. D., Mitchell, I., Lepin, L. Mora, Napolitano, J., Naumov, D., Naumova, E., Ochoa-Ricoux, J. P., Olshevskiy, A., Pan, H. -R., Park, J., Patton, S., Pec, V., Peng, J. C., Pinsky, L., Pun, C. S. J., Qi, F. Z., Qi, M., Qian, X., Raper, N., Ren, J., Rosero, R., Roskovec, B., Ruan, X. C., Steiner, H., Sun, J. L., 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. M., Wei, H. Y., Wei, L. H., Wen, L. J., Whisnant, K., White, C. G., Wong, H. L. H., Wong, S. C. F., Worcester, E., Wu, Q., Wu, W. J., Xia, D. M., Xing, Z. Z., Xu, J. L., Xue, T., Yang, C. G., Yang, L., Yang, M. S., Yang, Y. Z., Ye, M., Yeh, M., Young, B. L., Yu, H. Z., Yu, Z. Y., Yue, B. B., Zeng, S., Zhan, L., Zhang, C., Zhang, C. C., Zhang, F. Y., Zhang, H. H., Zhang, J. W., Zhang, Q. M., Zhang, R., Zhang, X. F., Zhang, X. T., Zhang, Y. M., Zhang, Y. X., Zhang, Y. Y., Zhang, Z. J., Zhang, Z. P., Zhang, Z. Y., Zhao, J., Zhou, L., Zhuang, H. L., and Zou, J. H.

Subjects
High Energy Physics - Experiment (hep-ex), Physics - Instrumentation and Detectors, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), Nuclear Experiment, High Energy Physics - Experiment
Abstract

This Letter reports the first extraction of individual antineutrino spectra from $^{235}$U and $^{239}$Pu fission and an improved measurement of the prompt energy spectrum of reactor antineutrinos at Daya Bay. The analysis uses $3.5\times 10^6$ inverse beta-decay candidates in four near antineutrino detectors in 1958 days. The individual antineutrino spectra of the two dominant isotopes, $^{235}$U and $^{239}$Pu, are extracted using the evolution of the prompt spectrum as a function of the isotope fission fractions. In the energy window of 4--6~MeV, a 7\% (9\%) excess of events is observed for the $^{235}$U ($^{239}$Pu) spectrum compared with the normalized Huber-Mueller model prediction. The significance of discrepancy is $4.0\sigma$ for $^{235}$U spectral shape compared with the Huber-Mueller model prediction. The shape of the measured inverse beta-decay prompt energy spectrum disagrees with the prediction of the Huber-Mueller model at $5.3\sigma$. In the energy range of 4--6~MeV, a maximal local discrepancy of $6.3\sigma$ is observed., Comment: Updated title

Published
2019

20. Cosmogenic neutron production at Daya Bay

Author

An, F.P., Balantekin, A.B., Band, H.R., Bishai, M., Blyth, S., Cao, D., Cao, G.F., Cao, J., Chan, Y.L., Chang, J.F., Chang, Y., Chen, H.S., Chen, S.M., Chen, Y., Chen, Y.X., Cheng, J., Cheng, Z.K., Cherwinka, J.J., Chu, M.C., Chukanov, A., Cummings, J.P., Ding, Y.Y., Diwan, M.V., Dolgareva, M., Dove, J., Dwyer, D.A., Edwards, W.R., Gill, R., Gonchar, M., Gong, G.H., Gong, H., Grassi, M., Gu, W.Q., Guo, L., Guo, X.H., Guo, Y.H., Guo, Z., Hackenburg, R.W., Hans, S., He, M., Heeger, K.M., Heng, Y.K., Higuera, A., Hsiung, Y.B., Hu, B.Z., Hu, T., Huang, H.X., Huang, X.T., Huang, Y.B., Huber, P., Huo, W., Hussain, G., Jaffe, D.E., Jen, K.L., Ji, X.L., Ji, X.P., Jiao, J.B., Johnson, R.A., Jones, D., Kang, L., Kettell, S.H., Khan, A., Koerner, L.W., Kohn, S., Kramer, M., Kwok, M.W., Langford, T.J., Lau, K., Lebanowski, L., Lee, J., Lee, J.H.C., Lei, R.T., Leitner, R., Leung, J.K.C., Li, C., Li, D.J., Li, F., Li, G.S., Li, Q.J., 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., Lin, S.K., Lin, Y.-C., Ling, J.J., Link, J.M., Littenberg, L., Littlejohn, B.R., Liu, J.C., Liu, J.L., Loh, C.W., Lu, C., Lu, H.Q., Lu, J.S., Luk, K.B., Ma, X.B., Ma, X.Y., Ma, Y.Q., Malyshkin, Y., Caicedo, D.A.M., McDonald, K.T., McKeown, R.D., Mitchell, I., Nakajima, Y., Napolitano, J., Naumov, D., Naumova, E., Ochoa-Ricoux, J.P., Olshevskiy, A., Pan, H.-R., Park, J., Patton, S., Pec, V., Peng, J.C., Pinsky, L., Pun, C.S.J., Qi, F.Z., Qi, M., Qian, X., Qiu, R.M., Raper, N., Ren, J., Rosero, R., Roskovec, B., Ruan, X.C., Steiner, H., Sun, J.L., Tang, W., Taychenachev, D., Treskov, K., Tsang, K.V., Tse, W.-H., Tull, C.E., Viaux, N., Viren, B., Vorobel, V., Wang, C.H., Wang, M., Wang, N.Y., Wang, R.G., Wang, W., Wang, X., Wang, Y.F., Wang, Z., Wang, Z.M., Wei, H.Y., Wen, L.J., Whisnant, K., White, C.G., Wise, T., Wong, H.L.H., Wong, S.C.F., Worcester, E., Wu, C.-H., Wu, Q., Wu, W.J., Xia, D.M., Xia, J.K., Xing, Z.Z., Xu, J.L., Xu, Y., Xue, T., Yang, C.G., Yang, H., Yang, L., Yang, M.S., Yang, M.T., Yang, Y.Z., Ye, M., Ye, Z., Yeh, M., Young, B.L., Yu, Z.Y., Zeng, S., Zhan, L., Zhang, C., Zhang, C.C., Zhang, H.H., Zhang, J.W., Zhang, Q.M., Zhang, R., Zhang, X.T., Zhang, Y.M., Zhang, Y.X., Zhang, Z.J., Zhang, Z.P., Zhang, Z.Y., Zhao, J., Zhou, L., Zhuang, H.L., Zou, J.H., and Collaboration, D.B.

Subjects
Physics, Muon, Physics - Instrumentation and Detectors, 010308 nuclear & particles physics, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Dark matter, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), Daya Bay Reactor Neutrino Experiment, Scintillator, 01 natural sciences, Power law, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), Double beta decay, 0103 physical sciences, Neutron, High Energy Physics::Experiment, 010306 general physics, Neutrino oscillation, Nuclear Experiment
Abstract

Neutrons produced by cosmic ray muons are an important background for underground experiments studying neutrino oscillations, neutrinoless double beta decay, dark matter, and other rare-event signals. A measurement of the neutron yield in the three different experimental halls of the Daya Bay Reactor Neutrino Experiment at varying depth is reported. The neutron yield in Daya Bay's liquid scintillator is measured to be $Y_n=(10.26\pm 0.86)\times 10^{-5}$, $(10.22\pm 0.87)\times 10^{-5}$, and $(17.03\pm 1.22)\times 10^{-5}~\mu^{-1}~$g$^{-1}~$cm$^2$ at depths of 250, 265, and 860 meters-water-equivalent. These results are compared to other measurements and the simulated neutron yield in Fluka and Geant4. A global fit including the Daya Bay measurements yields a power law coefficient of $0.77 \pm 0.03$ for the dependence of the neutron yield on muon energy., Comment: 13 pages, 13 figures

Published
2018

21. Perturbations to \mu-\tau\ symmetry in neutrino mixing

Author

Liao, Jiajun, Marfatia, D., and Whisnant, K.

Subjects
High Energy Physics - Phenomenology, Nuclear Experiment
Abstract

Many neutrino mixing scenarios that have \mu-\tau symmetry with \theta_{13}=0 are in disagreement with recent experimental results that indicate a nonzero value for \theta_{13}. We investigate the effect of small perturbations on Majorana mass matrices with \mu-\tau symmetry and derive analytic formulae for the corrections to the mixing angles. We find that since m_1 and m_2 are nearly degenerate, \mu-\tau symmetry mixing scenarios are able to explain the experimental data with about the same size perturbation for most values of \theta_{12}. This suggests that the underlying unperturbed mixing need not have \theta_{12} close to the experimentally preferred value. One consequence of this is that a new class of models with \mu-\tau symmetry is possible, with unperturbed \theta_{12} equal to zero or 90 degrees for arbitrary unperturbed \theta_{13}., Comment: 9 pages, 4 tables. Version to appear in PRD

Published
2012

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