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52. Seasonal Variation of the Underground Cosmic Muon Flux Observed 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., Huber, P., Huo, W., Hussain, G., Jaffe, D. E., Jen, K. L., Jetter, S., 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., 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, 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., Sebastiani, C., Steiner, H., 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, 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
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

The Daya Bay Experiment consists of eight identically designed detectors located in three underground experimental halls named as EH1, EH2, EH3, with 250, 265 and 860 meters of water equivalent vertical overburden, respectively. Cosmic muon events have been recorded over a two-year period. The underground muon rate is observed to be positively correlated with the effective atmospheric temperature and to follow a seasonal modulation pattern. The correlation coefficient $\alpha$, describing how a variation in the muon rate relates to a variation in the effective atmospheric temperature, is found to be $\alpha_{\text{EH1}} = 0.362\pm0.031$, $\alpha_{\text{EH2}} = 0.433\pm0.038$ and $\alpha_{\text{EH3}} = 0.641\pm0.057$ for each experimental hall., Comment: Updated to be identical to the published version

Published
2017
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53. Reactor Fuel Fraction Information on the Antineutrino Anomaly

Author

Giunti, C., Ji, X. P., Laveder, M., Li, Y. F., and Littlejohn, B. R.

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

We analyzed the evolution data of the Daya Bay reactor neutrino experiment in terms of short-baseline active-sterile neutrino oscillations taking into account the theoretical uncertainties of the reactor antineutrino fluxes. We found that oscillations are disfavored at $2.6\sigma$ with respect to a suppression of the $^{235}\text{U}$ reactor antineutrino flux and at $2.5\sigma$ with respect to variations of the $^{235}\text{U}$ and $^{239}\text{Pu}$ fluxes. On the other hand, the analysis of the rates of the short-baseline reactor neutrino experiments favor active-sterile neutrino oscillations and disfavor the suppression of the $^{235}\text{U}$ flux at $3.1\sigma$ and variations of the $^{235}\text{U}$ and $^{239}\text{Pu}$ fluxes at $2.8\sigma$. We also found that both the Daya Bay evolution data and the global rate data are well-fitted with composite hypotheses including variations of the $^{235}\text{U}$ or $^{239}\text{Pu}$ fluxes in addition to active-sterile neutrino oscillations. A combined analysis of the Daya Bay evolution data and the global rate data shows a slight preference for oscillations with respect to variations of the $^{235}\text{U}$ and $^{239}\text{Pu}$ fluxes. However, the best fits of the combined data are given by the composite models, with a preference for the model with an enhancement of the $^{239}\text{Pu}$ flux and relatively large oscillations., Comment: 9 pages

Published
2017
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54. 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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55. Updated Global 3+1 Analysis of Short-BaseLine Neutrino Oscillations

Author

Gariazzo, S., Giunti, C., Laveder, M., and Li, Y. F.

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

We present the results of an updated fit of short-baseline neutrino oscillation data in the framework of 3+1 active-sterile neutrino mixing. We first consider $\nu_e$ and $\bar\nu_e$ disappearance in the light of the Gallium and reactor anomalies. We discuss the implications of the recent measurement of the reactor $\bar\nu_e$ spectrum in the NEOS experiment, which shifts the allowed regions of the parameter space towards smaller values of $|U_{e4}|^2$. The beta-decay constraints allow us to limit the oscillation length between about 2 cm and 7 m at $3\sigma$ for neutrinos with an energy of 1 MeV. We then consider the global fit of the data in the light of the LSND anomaly, taking into account the constraints from $\nu_e$ and $\nu_\mu$ disappearance experiments, including the recent data of the MINOS and IceCube experiments. The combination of the NEOS constraints on $|U_{e4}|^2$ and the MINOS and IceCube constraints on $|U_{\mu4}|^2$ lead to an unacceptable appearance-disappearance tension which becomes tolerable only in a pragmatic fit which neglects the MiniBooNE low-energy anomaly. The minimization of the global $\chi^2$ in the space of the four mixing parameters $\Delta{m}^2_{41}$, $|U_{e4}|^2$, $|U_{\mu4}|^2$, and $|U_{\tau4}|^2$ leads to three allowed regions with narrow $\Delta{m}^{2}_{41}$ widths at $ \Delta m^2_{41} \approx 1.7 $ (best-fit), 1.3 (at $2\sigma$), 2.4 (at $3\sigma$) eV$^2$. The restrictions of the allowed regions of the mixing parameters with respect to our previous global fits are mainly due to the NEOS constraints. We present a comparison of the allowed regions of the mixing parameters with the sensitivities of ongoing experiments, which show that it is likely that these experiments will determine in a definitive way if the reactor, Gallium and LSND anomalies are due to active-sterile neutrino oscillations or not., Comment: 39 pages; improved treatment of the reactor flux uncertainties and other minor corrections

Published
2017
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56. RGB-D Salient Object Detection Based on Discriminative Cross-modal Transfer Learning

Author

Chen, Hao, Li, Y. F., and Su, Dan

Subjects
Computer Science - Computer Vision and Pattern Recognition
Abstract

In this work, we propose to utilize Convolutional Neural Networks to boost the performance of depth-induced salient object detection by capturing the high-level representative features for depth modality. We formulate the depth-induced saliency detection as a CNN-based cross-modal transfer problem to bridge the gap between the "data-hungry" nature of CNNs and the unavailability of sufficient labeled training data in depth modality. In the proposed approach, we leverage the auxiliary data from the source modality effectively by training the RGB saliency detection network to obtain the task-specific pre-understanding layers for the target modality. Meanwhile, we exploit the depth-specific information by pre-training a modality classification network that encourages modal-specific representations during the optimizing course. Thus, it could make the feature representations of the RGB and depth modalities as discriminative as possible. These two modules are pre-trained independently and then stitched to initialize and optimize the eventual depth-induced saliency detection model. Experiments demonstrate the effectiveness of the proposed novel pre-training strategy as well as the significant and consistent improvements of the proposed approach over other state-of-the-art methods., Comment: This paper has been rejected by CVPR2017, we plan to withdraw this manuscript for further revision

Published
2017

57. Solar, supernova, atmospheric and geo neutrino studies using JUNO detector

Author

Guo, W. L., Han, R., Li, Y. F., and Salamanna, G.

Subjects
High Energy Physics - Experiment, Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Phenomenology, Physics - Instrumentation and Detectors
Abstract

Aside from its primary purpose of shedding light on the mass hierarchy (MH) using reactor anti-neutrinos, the JUNO experiment in Jiangmen (China) will also contribute to study neutrinos from non-reactor sources. In this poster we review JUNO's goals in the realms of supernova, atmospheric, solar and geo-neutrinos; present the related experimental issues and provide the current estimates of its potential. For a typical galactic SN at a distance of 10 kpc, JUNO will record about 5000 events from inverse beta decay, 2000 events from elastic neutrino-proton scattering, 300 events from neutrino-electron scattering, and the charged current and neutral current interactions on the ${^{12}}{\rm C}$ nuclei. For atmospheric neutrinos, JUNO should be able to detect $\nu_e$ and $\nu_\mu$ charged current events. Optimistically, a determination of the MH could be achieved at the 1.8$\sigma$ (2.6$\sigma$) level after 10 (20) years of data taking. JUNO will also study solar neutrinos from ${^{7}}{\rm Be}$ and ${^{8}}{\rm B}$, at low ($\approx$1 MeV) and higher energies respectively, to improve our understanding of the matter effects on the oscillation mechanism and of the solar metallicity. Challenges come primarily from the radioactive and cosmogenic backgrounds: the expected performance for two benchmark scintillator radio-purities, are shown. The flux of geo-neutrinos gives us an insight on the Earth composition and formation. We will show how the increased sample size given by JUNO's large sensitive mass of 20 KTon liquid scintillator will provide data to answer to several geological questions among which the U/Th ratio and mantle measurements., Comment: Proceedings for ICHEP 2016

Published
2016

58. 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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61. Study of the wave packet treatment of neutrino oscillation 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, 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., 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, 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, High Energy Physics - Phenomenology
Abstract

The disappearance of reactor $\bar{\nu}_e$ observed by the Daya Bay experiment is examined in the framework of a model in which the neutrino is described by a wave packet with a relative intrinsic momentum dispersion $\sigma_\text{rel}$. Three pairs of nuclear reactors and eight antineutrino detectors, each with good energy resolution, distributed among three experimental halls, supply a high-statistics sample of $\bar{\nu}_e$ acquired at nine different baselines. This provides a unique platform to test the effects which arise from the wave packet treatment of neutrino oscillation. The modified survival probability formula was used to fit Daya Bay data, providing the first experimental limits: $2.38 \cdot 10^{-17} < \sigma_{\rm rel} < 0.23$. Treating the dimensions of the reactor cores and detectors as constraints, the limits are improved: $10^{-14} \lesssim \sigma_{\rm rel} < 0.23$, and an upper limit of $\sigma_{\rm rel} <0.20$ is obtained. All limits correspond to a 95\% C.L. Furthermore, the effect due to the wave packet nature of neutrino oscillation is found to be insignificant for reactor antineutrinos detected by the Daya Bay experiment thus ensuring an unbiased measurement of the oscillation parameters $\sin^22\theta_{13}$ and $\Delta m^2_{32}$ within the plane wave model.

Published
2016

62. 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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63. Improved Search for a Light Sterile Neutrino with the Full Configuration of the Daya Bay Experiment

Author

The 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, 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., 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
Abstract

This Letter reports an improved search for light sterile neutrino mixing in the electron antineutrino disappearance channel with the full configuration of the Daya Bay Reactor Neutrino Experiment. With an additional 404 days of data collected in eight antineutrino detectors, this search benefits from 3.6 times the statistics available to the previous publication, as well as from improvements in energy calibration and background reduction. A relative comparison of the rate and energy spectrum of reactor antineutrinos in the three experimental halls yields no evidence of sterile neutrino mixing in the $2\times10^{-4} \lesssim |\Delta m^{2}_{41}| \lesssim 0.3$ eV$^{2}$ mass range. The resulting limits on $\sin^{2}2\theta_{14}$ are improved by approximately a factor of 2 over previous results and constitute the most stringent constraints to date in the $|\Delta m^{2}_{41}| \lesssim 0.2$ eV$^{2}$ region., Comment: 6 pages, 3 figures, 1 table

Published
2016
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64. Limits on Active to Sterile Neutrino Oscillations from Disappearance Searches in the MINOS, Daya Bay, and Bugey-3 Experiments

Author

Bay, Daya, Collaborations, MINOS, Adamson, P., An, F. P., Anghel, I., Aurisano, A., Balantekin, A. B., Band, H. R., Barr, G., Bishai, M., Blake, A., Bock, S. Blyth G. J., Bogert, D., Cao, D., Cao, G. F., Cao, J., Cao, S. V., Carroll, T. J., Castromonte, C. M., Cen, W. R., Chan, Y. L., Chang, J. F., Chang, L. C., Chang, Y., Chen, H. S., Chen, Q. Y., Chen, R., Chen, S. M., Chen, Y., Chen, Y. X., Cheng, J., Cheng, J. -H., Chen, Y. P., Cheng, Z. K., Cherwinka, J. J., Childress, S., Chu, M. C., Chukanov, A., Coelho, J. A. B., Corwin, L., Cronin-Hennessy, D., Cummings, J. P., de Arcos, J., De Rijck, S., Deng, Z. Y., Devan, A. V., Devenish, N. E., Ding, X. F., Ding, Y. Y., Diwan, M. V., Dolgareva, M., Dove, J., Dwyer, D. A., Edwards, W. R., Escobar, C. O., Evans, J. J., Falk, E., Feldman, G. J., Flanagan, W., Frohne, M. V., Gabrielyan, M., Gallagher, H. R., Germani, S., Gill, R., Gomes, R. A., Gonchar, M., Gong, G. H., Gong, H., Goodman, M. C., Gouffon, P., Graf, N., Gran, R., Grassi, M., Grzelak, K., Gu, W. Q., Guan, M. Y., Guo, L., Guo, R. P., Guo, X. H., Guo, Z., Habig, A., Hackenburg, R. W., Hahn, S. R., Han, R., Hans, S., Hartnell, J., Hatcher, R., He, M., Heeger, K. M., Heng, Y. K., Higuera, A., Holin, A., Hor, Y. K., Hsiung, Y. B., Hu, B. Z., Hu, T., Hu, W., Huang, E. C., Huang, H. X., Huang, J., Huang, X. T., Huber, P., Huo, W., Hussain, G., Hylen, J., Irwin, G. M., Isvan, Z., Jaffe, D. E., Jaffke, P., James, C., Jen, K. L., Jensen, D., Jetter, S., Ji, X. L., Ji, X. P., Jiao, J. B., Johnson, R. A., de Jong, J. K., Joshi, J., Kafka, T., Kang, L., Kasahara, S. M. S., Kettell, S. H., Kohn, S., Koizumi, G., Kordosky, M., Kramer, M., Kreymer, A., Kwan, 1 K. K., Kwok, M. W., Kwok, T., Lang, K., 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., Link, J. J. Ling J. M., Litchfield, P. J., Littenberg, L., Littlejohn, B. R., Liu, D. W., Liu, J. C., Liu, J. L., Loh, C. W., Lu, C., Lu, H. Q., Lu, J. S., Lucas, P., Luk, K. B., Lv, Z., Ma, Q. M., Ma, X. B., Ma, X. Y., Ma, Y. Q., Malyshkin, Y., Mann, W. A., Marshak, M. L., Caicedo, D. A. Martinez, Mayer, N., McDonald, K. T., McGivern, C., McKeown, R. D., Medeiros, M. M., Mehdiyev, R., Meier, J. R., Messier, M. D., Miller, W. H., Mishra, S. R., Mitchell, I., Mooney, M., Moore, C. D., Mualem, L., Musser, J., Nakajima, Y., Naples, D., Napolitano, J., Naumov, D., Naumova, E., Nelson, J. K., Newman, H. B., Ngai, H. Y., Nichol, R. J., Ning, Z., Nowak, A., O'Connor, J., Ochoa-Ricoux, J. P., Olshevskiy, A., Orchanian, M., Pahlka, R. B., Paley, J., Pan, H. -R., Park, J., Patterson, R. B., Patton, S., Pawloski, G., Pec, V., Peng, J. C., Perch, A., Pfutzner, M. M., Phan, D. D., Phan-Budd, S., Pinsky, L., Plunkett, R. K., Poonthottathil, N., Pun, C. S. J., Qi, F. Z., Qi, M., Qian, X., Qiu, X., Radovic, A., Raper, N., Rebel, B., Ren, J., Rosenfeld, C., Rosero, R., Roskovec, B., Ruan, X. C., Rubin, H. A., Sail, P., Sanchez, M. C., Schneps, J., Schreckenberger, A., Schreiner, P., Sharma, R., Sher, S. Moed, Sousa, A., Steiner, H., Sun, G. X., Sun, J. L., Tagg, N., Talaga, R. L., Tang, W., Taychenachev, D., Thomas, J., Thomson, M. A., Timmons, X. Tian A., Todd, J., Tognini, S. C., Toner, R., Torretta, D., Treskov, K., Tsang, K. V., Tull, C. E., Tzanakos, G., Urheim, J., Vahle, P., 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., Webb, R. C., Weber, A., Wei, H. Y., Wen, L. J., Whisnant, K., White, C., Whitehead, L. Whitehead L. H., Wise, T., Wojcicki, S. G., 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, J. Y., 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., Zhang, L. ZhanC., Zhang, H. H., Zhang, J. W., Zhang, Q. M., Zhang, X. T., Zhang, Y. M., Zhang, Y. X., Zhang, Z. J., Zhang, Z. P., Zhang, Z. Y., 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
Abstract

Searches for a light sterile neutrino have been performed independently by the MINOS and the Daya Bay experiments using the muon (anti)neutrino and electron antineutrino disappearance channels, respectively. In this Letter, results from both experiments are combined with those from the Bugey-3 reactor neutrino experiment to constrain oscillations into light sterile neutrinos. The three experiments are sensitive to complementary regions of parameter space, enabling the combined analysis to probe regions allowed by the LSND and MiniBooNE experiments in a minimally extended four-neutrino flavor framework. Stringent limits on $\sin^2 2\theta_{\mu e}$ are set over 6 orders of magnitude in the sterile mass-squared splitting $\Delta m^2_{41}$. The sterile-neutrino mixing phase space allowed by the LSND and MiniBooNE experiments is excluded for $\Delta m^2_{41} < 0.8$ eV$^2$ at 95% CL$_s$., Comment: 8 pages, 4 figures, published in Physical Review Letters. Data release found at http://www-numi.fnal.gov/PublicInfo/forscientists.html and at https://wiki.bnl.gov/dayabay/index.php?title=Daya_Bay%27s_Sterile_Neutrino_Results_in_2016

Published
2016
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65. New measurement of $\theta_{13}$ via neutron capture on hydrogen at Daya Bay

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. -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., 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. J., 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., Konstantin, T., 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, 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, C. -H., Wu, Q., Xia, D. M., Xia, J. K., Xing, Z. Z., Xu, J. Y., Xu, J. L., Xu, J., Xu, Y., Xue, T., Yan, J., Yang, C. G., Yang, H., Yang, L., Yang, M. S., Yang, M. T., Ye, M., Ye, Z., Yeh, M., Young, B. L., Yu, G. Y., Yu, Z. Y., 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. F., Zhao, Y. B., Zhong, W. L., Zhou, L., Zhou, N., Zhuang, H. L., and Zou, J. H.

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

This article reports an improved independent measurement of neutrino mixing angle $\theta_{13}$ at the Daya Bay Reactor Neutrino Experiment. Electron antineutrinos were identified by inverse $\beta$-decays with the emitted neutron captured by hydrogen, yielding a data-set with principally distinct uncertainties from that with neutrons captured by gadolinium. With the final two of eight antineutrino detectors installed, this study used 621 days of data including the previously reported 217-day data set with six detectors. The dominant statistical uncertainty was reduced by 49%. Intensive studies of the cosmogenic muon-induced $^9$Li and fast neutron backgrounds and the neutron-capture energy selection efficiency, resulted in a reduction of the systematic uncertainty by 26%. The deficit in the detected number of antineutrinos at the far detectors relative to the expected number based on the near detectors yielded $\sin^22\theta_{13} = 0.071 \pm 0.011$ in the three-neutrino-oscillation framework. The combination of this result with the gadolinium-capture result is also reported., Comment: 26 pages, 23 figures

Published
2016
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66. A White Paper on keV Sterile Neutrino Dark Matter

Author

Adhikari, R., Agostini, M., Ky, N. Anh, Araki, T., Archidiacono, M., Bahr, M., Baur, J., Behrens, J., Bezrukov, F., Dev, P. S. Bhupal, Borah, D., Boyarsky, A., de Gouvea, A., Pires, C. A. de S., de Vega, H. J., Dias, A. G., Di Bari, P., Djurcic, Z., Dolde, K., Dorrer, H., Durero, M., Dragoun, O., Drewes, M., Drexlin, G., Düllmann, Ch. E., Eberhardt, K., Eliseev, S., Enss, C., Evans, N. W., Faessler, A., Filianin, P., Fischer, V., Fleischmann, A., Formaggio, J. A., Franse, J., Fraenkle, F. M., Frenk, C. S., Fuller, G., Gastaldo, L., Garzilli, A., Giunti, C., Glück, F., Goodman, M. C., Gonzalez-Garcia, M. C., Gorbunov, D., Hamann, J., Hannen, V., Hannestad, S., Hansen, S. H., Hassel, C., Heeck, J., Hofmann, F., Houdy, T., Huber, A., Iakubovskyi, D., Ianni, A., Ibarra, A., Jacobsson, R., Jeltema, T., Jochum, J., Kempf, S., Kieck, T., Korzeczek, M., Kornoukhov, V., Lachenmaier, T., Laine, M., Langacker, P., Lasserre, T., Lesgourgues, J., Lhuillier, D., Li, Y. F., Liao, W., Long, A. W., Maltoni, M., Mangano, G., Mavromatos, N. E., Menci, N., Merle, A., Mertens, S., Mirizzi, A., Monreal, B., Nozik, A., Neronov, A., Niro, V., Novikov, Y., Oberauer, L., Otten, E., Palanque-Delabrouille, N., Pallavicini, M., Pantuev, V. S., Papastergis, E., Parke, S., Pascoli, S., Pastor, S., Patwardhan, A., Pilaftsis, A., Radford, D. C., Ranitzsch, P. C. -O., Rest, O., Robinson, D. J., da Silva, P. S. Rodrigues, Ruchayskiy, O., Sanchez, N. G., Sasaki, M., Saviano, N., Schneider, A., Schneider, F., Schwetz, T., Schönert, S., Scholl, S., Shankar, F., Shrock, R., Steinbrink, N., Strigari, L., Suekane, F., Suerfu, B., Takahashi, R., Van, N. Thi Hong, Tkachev, I., Totzauer, M., Tsai, Y., Tully, C. G., Valerius, K., Valle, J. W. F., Venos, D., Viel, M., Vivier, M., Wang, M. Y., Weinheimer, C., Wendt, K., Winslow, L., Wolf, J., Wurm, M., Xing, Z., Zhou, S., and Zuber, K.

Subjects
High Energy Physics - Phenomenology, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Astrophysics of Galaxies, High Energy Physics - Experiment
Abstract

We present a comprehensive review of keV-scale sterile neutrino Dark Matter, collecting views and insights from all disciplines involved - cosmology, astrophysics, nuclear, and particle physics - in each case viewed from both theoretical and experimental/observational perspectives. After reviewing the role of active neutrinos in particle physics, astrophysics, and cosmology, we focus on sterile neutrinos in the context of the Dark Matter puzzle. Here, we first review the physics motivation for sterile neutrino Dark Matter, based on challenges and tensions in purely cold Dark Matter scenarios. We then round out the discussion by critically summarizing all known constraints on sterile neutrino Dark Matter arising from astrophysical observations, laboratory experiments, and theoretical considerations. In this context, we provide a balanced discourse on the possibly positive signal from X-ray observations. Another focus of the paper concerns the construction of particle physics models, aiming to explain how sterile neutrinos of keV-scale masses could arise in concrete settings beyond the Standard Model of elementary particle physics. The paper ends with an extensive review of current and future astrophysical and laboratory searches, highlighting new ideas and their experimental challenges, as well as future perspectives for the discovery of sterile neutrinos., Comment: v2: 257 pages, 57 figures, content matches published version [JCAP01(2017)025]; over 100 authors from several different communities

Published
2016
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67. 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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68. The Detector System of The Daya Bay Reactor Neutrino Experiment

Author

An, F. P., Bai, J. Z., Balantekin, A. B., Band, H. R., Beavis, D., Beriguete, W., Bishai, M., Blyth, S., Brown, R. L., Butorov, I., Cao, D., Cao, G. F., Cao, J., Carr, R., Cen, W. R., Chan, W. T., Chan, Y. L., Chang, J. F., Chang, L. C., Chang, Y., Chasman, C., Chen, H. Y., Chen, H. S., Chen, M. J., Chen, Q. Y., Chen, S. J., Chen, S. M., Chen, X. C., Chen, X. H., Chen, X. S., Chen, Y. X., Chen, Y., Cheng, J. H., Cheng, J., Cheng, Y. P., Cherwinka, J. J., Chidzik, S., Chow, K., Chu, M. C., Cummings, J. P., de Arcos, J., Deng, Z. Y., Ding, X. F., Ding, Y. Y., Diwan, M. V., Dong, L., Dove, J., Draeger, E., Du, X. F., Dwyer, D. A., Edwards, W. R., Ely, S. R., Fang, S. D., Fu, J. Y., Fu, Z. W., Ge, L. Q., Ghazikhanian, V., Gill, R., Goett, J., Gonchar, M., Gong, G. H., Gong, H., Gornushkin, Y. A., Grassi, M., Greenler, L. S., Gu, W. Q., Guan, M. Y., Guo, R. P., Guo, X. H., Hackenburg, R. W., Hahn, R. L., Han, R., Hans, S., He, M., He, Q., He, W. S., Heeger, K. M., Heng, Y. K., Higuera, A., Hinrichs, P., Ho, T. H., Hoff, M., Hor, Y. K., Hsiung, Y. B., Hu, B. Z., Hu, L. M., Hu, L. J., Hu, T., Hu, W., Huang, E. C., Huang, H. Z., Huang, H. X., Huang, P. W., Huang, X., Huang, X. T., Huber, P., Hussain, G., Isvan, Z., Jaffe, D. E., Jaffke, P., Jen, K. L., Jetter, S., Ji, X. P., Ji, X. L., Jiang, H. J., Jiang, W. Q., Jiao, J. B., Johnson, R. A., Joseph, J., Kang, L., Kettell, S. H., Kohn, S., Kramer, M., Kwan, K. K., Kwok, M. W., Kwok, T., Lai, C. Y., Lai, W. C., Lai, W. H., Langford, T. J., Lau, K., Lebanowski, L., Lee, J., Lee, M. K. P., Lei, R. T., Leitner, R., Leung, J. K. C., Leung, K. Y., Lewis, C. A., Li, B., Li, C., Li, D. J., Li, F., Li, G. S., Li, J., Li, N. Y., Li, Q. J., Li, S. F., Li, S. C., Li, W. D., Li, X. B., Li, X. N., Li, X. Q., Li, Y., Li, Y. F., Li, Z. B., Liang, H., Liang, J., Lin, C. J., Lin, G. L., Lin, P. Y., Lin, S. X., Lin, S. K., Lin, Y. C., Ling, J. J., Link, J. M., Littenberg, L., Littlejohn, B. R., Liu, B. J., Liu, C., Liu, D. W., Liu, H., Liu, J. L., Liu, J. C., Liu, S., Liu, S. S., Liu, X., Liu, Y. B., Lu, C., Lu, H. Q., Lu, J. S., Luk, A., Luk, K. B., Luo, T., Luo, X. L., Ma, L. H., Ma, Q. M., Ma, X. Y., Ma, X. B., Ma, Y. Q., Mayes, B., McDonald, K. T., McFarlane, M. C., McKeown, R. D., Meng, Y., Mitchell, I., Mohapatra, D., Kebwaro, J. Monari, Morgan, J. E., Nakajima, Y., Napolitano, J., Naumov, D., Naumova, E., Newsom, C., Ngai, H. Y., Ngai, W. K., Nie, Y. B., Ning, Z., Ochoa-Ricoux, J. P., Olshevskiy, A., Pagac, A., Pan, H. -R., Patton, S., Pearson, C., 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., Sands III, W. R., Seilhan, B., Shao, B. B., Shih, K., Song, W. Y., Steiner, H., Stoler, P., Stuart, M., Sun, G. X., Sun, J. L., Tagg, N., Tam, Y. H., Tanaka, H. K., Tang, W., Tang, X., Taychenachev, D., Themann, H., Torun, Y., Trentalange, S., Tsai, O., Tsang, K. V., Tsang, R. H. M., Tull, C. E., Tung, Y. C., Viaux, N., Viren, B., Virostek, S., Vorobel, V., Wang, C. H., Wang, L. S., Wang, L. Y., Wang, L. Z., Wang, M., Wang, N. Y., Wang, R. G., Wang, T., Wang, W., Wang, W. W., Wang, X. T., Wang, X., Wang, Y. F., Wang, Z., Wang, Z. M., Webber, D. M., Wei, H. Y., Wei, Y. D., Wen, L. J., Wenman, D. L., Whisnant, K., White, C. G., Whitehead, L., Whitten Jr., C. A., Wilhelmi, J., Wise, T., Wong, H. C., Wong, H. L. H., Wong, J., Wong, S. C. F., Worcester, E., Wu, F. F., Wu, Q., Xia, D. M., Xia, J. K., Xiang, S. T., Xiao, Q., Xing, Z. Z., Xu, G., Xu, J. Y., Xu, J. L., Xu, J., Xu, W., Xu, Y., Xue, T., Yan, J., Yang, C. G., Yang, L., Yang, M. S., Yang, M. T., Ye, M., Yeh, M., Yeh, Y. S., Yip, K., Young, B. L., Yu, G. Y., Yu, Z. Y., Zeng, S., Zhan, L., Zhang, C., Zhang, F. H., Zhang, H. H., Zhang, J. W., Zhang, K., Zhang, Q. X., Zhang, Q. M., Zhang, S. H., Zhang, X. T., Zhang, Y. C., Zhang, Y. H., 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., Zhou, Z. Y., Zhuang, H. L., Zimmerman, S., and Zou, J. H.

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

The Daya Bay experiment was the first to report simultaneous measurements of reactor antineutrinos at multiple baselines leading to the discovery of $\bar{\nu}_e$ oscillations over km-baselines. Subsequent data has provided the world's most precise measurement of $\rm{sin}^22\theta_{13}$ and the effective mass splitting $\Delta m_{ee}^2$. The experiment is located in Daya Bay, China where the cluster of six nuclear reactors is among the world's most prolific sources of electron antineutrinos. Multiple antineutrino detectors are deployed in three underground water pools at different distances from the reactor cores to search for deviations in the antineutrino rate and energy spectrum due to neutrino mixing. Instrumented with photomultiplier tubes (PMTs), the water pools serve as shielding against natural radioactivity from the surrounding rock and provide efficient muon tagging. Arrays of resistive plate chambers over the top of each pool provide additional muon detection. The antineutrino detectors were specifically designed for measurements of the antineutrino flux with minimal systematic uncertainty. Relative detector efficiencies between the near and far detectors are known to better than 0.2%. With the unblinding of the final two detectors' baselines and target masses, a complete description and comparison of the eight antineutrino detectors can now be presented. This paper describes the Daya Bay detector systems, consisting of eight antineutrino detectors in three instrumented water pools in three underground halls, and their operation through the first year of eight detector data-taking., Comment: 52 pages, 51 figures

Published
2015
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69. Light sterile neutrinos

Author

Gariazzo, S., Giunti, C., Laveder, M., Li, Y. F., and Zavanin, E. M.

Subjects
High Energy Physics - Phenomenology, Astrophysics - Cosmology and Nongalactic Astrophysics, High Energy Physics - Experiment, Physics - Accelerator Physics
Abstract

The theory and phenomenology of light sterile neutrinos at the eV mass scale is reviewed. The reactor, Gallium and LSND anomalies are briefly described and interpreted as indications of the existence of short-baseline oscillations which require the existence of light sterile neutrinos. The global fits of short-baseline oscillation data in 3+1 and 3+2 schemes are discussed, together with the implications for beta-decay and neutrinoless double-beta decay. The cosmological effects of light sterile neutrinos are briefly reviewed and the implications of existing cosmological data are discussed. The review concludes with a summary of future perspectives., Comment: 41 pages; final version to be published as a Topical Review in Journal of Physics G

Published
2015
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70. Resonantly excited betatron hard X-Rays from Ionization Injected Electron Beam in a Laser Plasma Accelerator

Author

Huang, K., Chen, L. M., Li, Y. F., Li, D. Z., Tao, M. Z., Mirzaie, M., Ma, Y., Zhao, J. R., Li, M. H., Chen, M., Hafz, N., Sokollik, T., Sheng, Z. M., and Zhang, J.

Subjects
Physics - Plasma Physics
Abstract

A new scheme for bright hard x-ray emission from laser wakefield electron accelerator is reported, where pure nitrogen gas is adopted. Intense Betatron x-ray beams are generated from ionization injected K-shell electrons of nitrogen into the accelerating wave bucket. The x-ray radiation shows synchrotron-like spectrum with total photon yield 8$\times$10$^8$/shot and $10^8$ over 110keV. In particular, the betatron hard x-ray photon yield is 10 times higher compared to the case of helium gas under the same laser parameters. Particle-in-cell simulation suggests that the enhancement of the x-ray yield results from ionization injection, which enables the electrons to be quickly accelerated to the driving laser region for subsequent betatron resonance. Employing the present scheme,the single stage nitrogen gas target could be used to generate stable high brightness betatron hard x-ray beams.

Published
2015

71. 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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74. Search for a Light Sterile Neutrino at Daya Bay

Author

An, F. P., Balantekin, A. B., Band, H. R., Beriguete, W., Bishai, M., Blyth, S., Butorov, I., Cao, G. F., Cao, J., Chan, Y. L., Chang, J. F., Chang, L. C., Chang, Y., Chasman, C., Chen, H., Chen, Q. Y., Chen, S. M., Chen, X., Chen, Y. X., Chen, Y., 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., Grassi, M., Gu, W. Q., Guan, M. Y., Guo, X. H., Hackenburg, R. W., Han, G. H., Hans, S., He, M., Heeger, K. M., Heng, Y. K., Hinrichs, P., Hor, Y. K., Hsiung, Y. B., Hu, B. Z., Hu, L. M., Hu, L. J., Hu, T., Hu, W., Huang, E. C., Huang, H., Huang, X. T., Huber, P., Hussain, G., Isvan, Z., Jaffe, D. E., Jaffke, P., Jen, K. L., Jetter, S., Ji, X. P., Ji, X. L., 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., 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, P. Y., Lin, S. K., Lin, Y. C., 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., Liu, Y. B., Lu, C., Lu, H. Q., Luk, K. B., Ma, Q. M., Ma, X. Y., Ma, X. B., Ma, Y. Q., McDonald, K. T., McFarlane, M. C., McKeown, R. D., Meng, Y., Mitchell, I., Kebwaro, J. Monari, Nakajima, Y., Napolitano, J., Naumov, D., Naumova, E., Nemchenok, I., 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., Tam, Y. H., Tang, X., Themann, H., 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, 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. Y., 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. Y., Xu, J. L., Xu, J., Xu, Y., Xue, T., Yan, J., Yang, C. C., Yang, L., Yang, M. S., Yang, M. T., Ye, M., Yeh, M., Yeh, Y. S., Young, B. L., Yu, G. Y., Yu, J. Y., Yu, Z. Y., Zang, S. L., Zeng, B., Zhan, L., Zhang, C., Zhang, F. H., Zhang, J. W., Zhang, Q. M., Zhang, Q., Zhang, S. H., Zhang, Y. C., Zhang, Y. M., Zhang, Y. H., Zhang, Y. X., Zhang, Z. J., Zhang, Z. Y., Zhang, Z. P., Zhao, J., Zhao, Q. W., Zhao, Y., 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
Abstract

A search for light sterile neutrino mixing was performed with the first 217 days of data from the Daya Bay Reactor Antineutrino Experiment. The experiment's unique configuration of multiple baselines from six 2.9~GW$_{\rm th}$ nuclear reactors to six antineutrino detectors deployed in two near (effective baselines 512~m and 561~m) and one far (1579~m) underground experimental halls makes it possible to test for oscillations to a fourth (sterile) neutrino in the $10^{\rm -3}~{\rm eV}^{2} < |\Delta m_{41}^{2}| < 0.3~{\rm eV}^{2}$ range. The relative spectral distortion due to electron antineutrino disappearance was found to be consistent with that of the three-flavor oscillation model. The derived limits on $\sin^22\theta_{14}$ cover the $10^{-3}~{\rm eV}^{2} \lesssim |\Delta m^{2}_{41}| \lesssim 0.1~{\rm eV}^{2}$ region, which was largely unexplored., Comment: 7 pages, 4 figures

Published
2014
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75. Independent Measurement of Theta13 via Neutron Capture on Hydrogen at Daya Bay

Author

Daya Bay Collaboration, An, F. P., Balantekin, A. B., Band, H. R., Beriguete, W., Bishai, M., Blyth, S., Butorov, I., Cao, G. F., Cao, J., Chan, Y. L., Chang, J. F., Chang, L. C., Chang, Y., Chasman, C., Chen, H., Chen, Q. Y., Chen, S. M., Chen, X., Chen, Y. X., Chen, Y., 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., Gu, W. Q., Guan, M. Y., Guo, X. H., Hackenburg, R. W., Han, G. H., Hans, S., He, M., Heeger, K. M., Heng, Y. K., Hinrichs, P., Hor, Y. K., Hsiung, Y. B., Hu, B. Z., Hu, L. M., Hu, L. J., Hu, T., Hu, W., Huang, E. C., Huang, H., Huang, X. T., Huber, P., Hussain, G., Isvan, Z., Jaffe, D. E., Jaffke, P., Jen, K. L., Jetter, S., Ji, X. P., Ji, X. L., 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., 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, P. Y., Lin, S. K., Lin, Y. C., 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., Liu, Y. B., Lu, C., Lu, H. Q., Luk, K. -B., Ma, Q. M., Ma, X. Y., Ma, X. B., Ma, Y. Q., McDonald, K. T., McFarlane, M. C., McKeown, R. D., Meng, Y., Mitchell, I., Kebwaro, J. Monari, Nakajima, Y., Napolitano, J., Naumov, D., Naumova, E., Nemchenok, I., 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., Tam, Y. H., Tang, X., Themann, H., 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, 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. Y., 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. Y., Xu, J. L., Xu, J., Xu, Y., Xue, T., Yan, J., Yang, C. C., Yang, L., Yang, M. S., Yang, M. T., Ye, M., Yeh, M., Yeh, Y. S., Young, B. L., Yu, G. Y., Yu, J. Y., Yu, Z. Y., Zang, S. L., Zeng, B., Zhan, L., Zhang, C., Zhang, F. H., Zhang, J. W., Zhang, Q. M., Zhang, Q., Zhang, S. H., Zhang, Y. C., Zhang, Y. M., Zhang, Y. H., Zhang, Y. X., Zhang, Z. J., Zhang, Z. Y., Zhang, Z. P., Zhao, J., Zhao, Q. W., Zhao, Y., 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, Physics - Instrumentation and Detectors
Abstract

A new measurement of the $\theta_{13}$ mixing angle has been obtained at the Daya Bay Reactor Neutrino Experiment via the detection of inverse beta decays tagged by neutron capture on hydrogen. The antineutrino events for hydrogen capture are distinct from those for gadolinium capture with largely different systematic uncertainties, allowing a determination independent of the gadolinium-capture result and an improvement on the precision of $\theta_{13}$ measurement. With a 217-day antineutrino data set obtained with six antineutrino detectors and from six 2.9 GW$_{th}$ reactors, the rate deficit observed at the far hall is interpreted as $\sin^22\theta_{13}=0.083\pm0.018$ in the three-flavor oscillation model. When combined with the gadolinium-capture result from Daya Bay, we obtain $\sin^22\theta_{13}=0.089\pm0.008$ as the final result for the six-antineutrino-detector configuration of the Daya Bay experiment.

Published
2014
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76. 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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78. Pragmatic View of Short-Baseline Neutrino Oscillations

Author

Giunti, C., Laveder, M., Li, Y. F., and Long, H. W.

Subjects
High Energy Physics - Phenomenology, Astrophysics - Cosmology and Extragalactic Astrophysics, High Energy Physics - Experiment
Abstract

We present the results of global analyses of short-baseline neutrino oscillation data in 3+1, 3+2 and 3+1+1 neutrino mixing schemes. We show that the data do not allow us to abandon the simplest 3+1 scheme in favor of the more complex 3+2 and 3+1+1 schemes. We present the allowed region in the 3+1 parameter space, which is located at $\Delta{m}^2_{41}$ between 0.82 and 2.19 $\text{eV}^2$ at $3\sigma$. The case of no oscillations is disfavored by about $6\sigma$, which decreases dramatically to about $2\sigma$ if the LSND data are not considered. Hence, new high-precision experiments are needed to check the LSND signal., Comment: 6 pages. Final version published in Phys. Rev. D 88, 073008 (2013)

Published
2013
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79. Observation of in-gap surface states in the Kondo insulator SmB6 by photoemission

Author

Jiang, J., Li, S., Zhang, T., Sun, Z., Chen, F., Ye, Z. R., Xu, M., Ge, Q. Q., Tan, S. Y., Niu, X. H., Xia, M., Xie, B. P., Li, Y. F., Chen, X. H., Wen, H. H., and Feng, D. L.

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

Kondo insulators (KIs) are strongly correlated materials in which the interactions between 4f and conduction electrons lead to a hybridization gap opening at low temperature 1-2. SmB6 is a typical KI, but its resistivity does not diverge at low temperatures, which was attributed to some in-gap states 3-10. However after several decades of research, the nature and origin of the in-gap states remain unclear. Recent band calculation and transport measurements suggest that the in-gap states could actually be ascribed to topological surface states. SmB6 thus might be the first realization of topological Kondo insulator (TKI) 13, the strongly correlated version of topological insulator (TI) 11,12. Here by performing angle-resolved photoemission spectroscopy (ARPES), we directly observed several dispersive states within the hybridization gap of SmB6, which cross the Fermi level and show negligible kz dependence, indicative of their surface origin. Furthermore, the circular dichroism (CD) ARPES results of the in-gap states suggest the chirality of orbital momentum, and temperature dependent measurements have shown that the in-gap states vanish simultaneously with the hybridization gap around 150 K. These strongly suggest their possible topological origin., Comment: 18 pages, 8 figures

Published
2013
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80. Day-Night Asymmetries in Active-Sterile Solar Neutrino Oscillations

Author

Long, H. W., Li, Y. F., and Giunti, C.

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

Day-night asymmetries in active-sterile solar neutrino oscillations are discussed in the general $3+N_{s}$ mixing framework with three active and N_s sterile neutrinos. Analytical expressions of the probability of neutrino flavor transitions in the Earth in the perturbative approximation and in the slab approximation are presented and the effects of active-sterile mixing and of the CP-violating phases are discussed. The accuracy of the analytical approximations and the properties of the day-night asymmetries are illustrated numerically in the 3+1 neutrino mixing framework., Comment: 30 pages, 8 gigures, publshed in JHEP

Published
2013
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81. CP-violating Phases in Active-Sterile Solar Neutrino Oscillations

Author

Long, H. W., Li, Y. F., and Giunti, C.

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

Effects of CP-violating phases in active-sterile solar neutrino oscillations are discussed in a general scheme of 3+N_{s} mixing, without any constraint on the mixing between the three active and the N_{s} sterile neutrinos, assuming only a realistic hierarchy of neutrino mass-squared differences. A generalized Parke formula describing the neutrino oscillation probabilities inside the Sun is calculated. The validity of the analytical calculation and the probability variation due to the unknown CP-violating phases are illustrated with a numerical calculation of the evolution equation in the case of 3+1 neutrino mixing., Comment: 24 pages, 8 figures, Final version published in Phys. Rev. D 87, 113004 (2013)

Published
2013
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83. Short-Baseline Electron Neutrino Oscillation Length After Troitsk

Author

Giunti, C., Laveder, M., Li, Y. F., and Long, H. W.

Subjects
High Energy Physics - Phenomenology, Astrophysics - Cosmology and Extragalactic Astrophysics, High Energy Physics - Experiment
Abstract

We discuss the implications for short-baseline electron neutrino disappearance in the 3+1 mixing scheme of the recent Troitsk bounds on the mixing of a neutrino with mass between 2 and 100 eV. Considering the Troitsk data in combination with the results of short-baseline nu_e and antinu_e disappearance experiments, which include the reactor and Gallium anomalies, we derive a 2 sigma allowed range for the effective neutrino squared-mass difference between 0.85 and 43 eV^2. The upper bound implies that it is likely that oscillations in distance and/or energy can be observed in radioactive source experiments. It is also favorable for the ICARUS@CERN experiment, in which it is likely that oscillations are not washed-out in the near detector. We discuss also the implications for neutrinoless double-beta decay., Comment: 5 pages. Final version published in Phys.Rev. D87 (2013) 013004

Published
2012
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84. Update of Short-Baseline Electron Neutrino and Antineutrino Disappearance

Author

Giunti, C., Laveder, M., Li, Y. F., Liu, Q. Y., and Long, H. W.

Subjects
High Energy Physics - Phenomenology, Astrophysics - Cosmology and Extragalactic Astrophysics, High Energy Physics - Experiment
Abstract

We present a complete update of the analysis of electron neutrino and antineutrino disappearance experiments in terms of neutrino oscillations in the framework of 3+1 neutrino mixing, taking into account the Gallium anomaly, the reactor anomaly, solar neutrino data and nu_e-C scattering data. We discuss the implications of a recent 71Ga(3He,3H)71Ge measurement which give information on the neutrino cross section in Gallium experiments. We discuss the solar bound on active-sterile mixing and present our numerical results. We discuss the connection between the results of the fit of neutrino oscillation data and the heavy neutrino mass effects in beta-decay experiments (considering new Mainz data) and neutrinoless double-beta decay experiments (considering the recent EXO results)., Comment: 15 pages. Final version published in Phys.Rev. D86 (2012) 113014

Published
2012
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85. Light Sterile Neutrinos: A White Paper

Author

Abazajian, K. N., Acero, M. A., Agarwalla, S. K., Aguilar-Arevalo, A. A., Albright, C. H., Antusch, S., Arguelles, C. A., Balantekin, A. B., Barenboim, G., Barger, V., Bernardini, P., Bezrukov, F., Bjaelde, O. E., Bogacz, S. A., Bowden, N. S., Boyarsky, A., Bravar, A., Berguno, D. Bravo, Brice, S. J., Bross, A. D., Caccianiga, B., Cavanna, F., Chun, E. J., Cleveland, B. T., Collin, A. P., Coloma, P., Conrad, J. M., Cribier, M., Cucoanes, A. S., D'Olivo, J. C., Das, S., de Gouvea, A., Derbin, A. V., Dharmapalan, R., Diaz, J. S., Ding, X. J., Djurcic, Z., Donini, A., Duchesneau, D., Ejiri, H., Elliott, S. R., Ernst, D. J., Esmaili, A., Evans, J. J., Fernandez-Martinez, E., Figueroa-Feliciano, E., Fleming, B. T., Formaggio, J. A., Franco, D., Gaffiot, J., Gandhi, R., Gao, Y., Garvey, G. T., Gavrin, V. N., Ghoshal, P., Gibin, D., Giunti, C., Gninenko, S. N., Gorbachev, V. V., Gorbunov, D. S., Guenette, R., Guglielmi, A., Halzen, F., Hamann, J., Hannestad, S., Haxton, W., Heeger, K. M., Henning, R., Hernandez, P., Huber, P., Huelsnitz, W., Ianni, A., Ibragimova, T. V., Karadzhov, Y., Karagiorgi, G., Keefer, G., Kim, Y. D., Kopp, J., Kornoukhov, V. N., Kusenko, A., Kyberd, P., Langacker, P., Lasserre, Th., Laveder, M., Letourneau, A., Lhuillier, D., Li, Y. F., Lindner, M., Link, J. M., Littlejohn, B. L., Lombardi, P., Long, K., Lopez-Pavon, J., Louis, W. C., Ludhova, L., Lykken, J. D., Machado, P. A. N., Maltoni, M., Mann, W. A., Marfatia, D., Mariani, C., Matveev, V. A., Mavromatos, N. E., Melchiorri, A., Meloni, D., Mena, O., Mention, G., Merle, A., Meroni, E., Mezzetto, M., Mills, G. B., Minic, D., Miramonti, L., Mohapatra, D., Mohapatra, R. N., Montanari, C., Mori, Y., Mueller, Th. A., Mumm, H. P., Muratova, V., Nelson, A. E., Nico, J. S., Noah, E., Nowak, J., Smirnov, O. Yu., Obolensky, M., Pakvasa, S., Palamara, O., Pallavicini, M., Pascoli, S., Patrizii, L., Pavlovic, Z., Peres, O. L. G., Pessard, H., Pietropaolo, F., Pitt, M. L., Popovic, M., Pradler, J., Ranucci, G., Ray, H., Razzaque, S., Rebel, B., Robertson, R. G. H., Rodejohann, W., Rountree, S. D., Rubbia, C., Ruchayskiy, O., Sala, P. R., Scholberg, K., Schwetz, T., Shaevitz, M. H., Shaposhnikov, M., Shrock, R., Simone, S., Skorokhvatov, M., Sorel, M., Sousa, A., Spergel, D. N., Spitz, J., Stanco, L., Stancu, I., Suzuki, A., Takeuchi, T., Tamborra, I., Tang, J., Testera, G., Tian, X. C., Tonazzo, A., Tunnell, C. D., Van de Water, R. G., Verde, L., Veretenkin, E. P., Vignoli, C., Vivier, M., Vogelaar, R. B., Wascko, M. O., Wilkerson, J. F., Winter, W., Wong, Y. Y. Y., Yanagida, T. T., Yasuda, O., Yeh, M., Yermia, F., Yokley, Z. W., Zeller, G. P., Zhan, L., and Zhang, H.

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

This white paper addresses the hypothesis of light sterile neutrinos based on recent anomalies observed in neutrino experiments and the latest astrophysical data.

Published
2012

86. Q_6 flavor symmetry model for the extension of the minimal standard model by three right-handed sterile neutrinos

Author

Araki, Takeshi and Li, Y. F.

Subjects
High Energy Physics - Phenomenology, Astrophysics - Cosmology and Extragalactic Astrophysics
Abstract

The extension of the minimal standard model by three right-handed sterile neutrinos with masses smaller than the electroweak scale (nuMSM) is discussed in a Q_6 flavor symmetry framework. The lightness of the keV sterile neutrino and the near mass degeneracy of two heavier sterile neutrinos are naturally explained by exploiting group properties of Q_6. A normal hierarchical mass spectrum and an approximately mu-tau symmetric mass matrix are predicted for three active neutrinos. Nonzero theta_{13} can be obtained together with a deviation of theta_{23} from the maximality, where both mixing angles are consistent with the latest global data including T2K and MINOS results. Furthermore, the tiny active-sterile mixing is related to the mass ratio between the lightest active and lightest sterile neutrinos., Comment: 14 pages, 1 figure, Title changed for publication, final version to appear in Phys. Rev. D 85, 065016 (2012)

Published
2011
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87. Vanishing effective mass of the neutrinoless double beta decay including light sterile neutrinos

Author

Li, Y. F. and Liu, Si-shuo

Subjects
High Energy Physics - Phenomenology
Abstract

Light sterile neutrinos with masses at the sub-eV or eV scale are hinted by current experimental and cosmological data. Assuming the Majorana nature of these hypothetical particles, we discuss their effects in the neutrinoless double beta decay by exploring the implications of a vanishing effective Majorana neutrino mass. Allowed ranges of neutrino masses, mixing angles and Majorana CP-violating phases are illustrated in some instructive cases for both normal and inverted mass hierarchies of three active neutrinos., Comment: 14 pages, 4 figures, more discussions and references added, accepted for publication in PLB

Published
2011
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88. Neutrinos as Hot or Warm Dark Matter

Author

Li, Y. F. and Xing, Zhi-zhong

Subjects
High Energy Physics - Phenomenology, Astrophysics - Cosmology and Extragalactic Astrophysics
Abstract

Both active and sterile sub-eV neutrinos can serve for hot dark matter (DM). On the other hand, keV sterile neutrinos could be a good candidate for warm DM. The beta-decaying (e.g., H-3 and Ru-106) and EC-decaying (e.g., Ho-163) nuclei are considered as the most promising targets to capture those extremely low energy neutrinos and antineutrinos, respectively. We calculate the capture rates of relic electron neutrinos and antineutrinos against the corresponding beta-decay or EC-decay backgrounds in different flavor mixing schemes. We stress that such direct laboratory measurements of hot or warm DM might not be hopeless in the long term., Comment: 10 pages, 5 figures, references updated, published in Acta Phys. Polon. B 42, 2193 (2011)

Published
2011

89. Captures of Hot and Warm Sterile Antineutrino Dark Matter on EC-decaying Ho-163 Nuclei

Author

Li, Y. F. and Xing, Zhi-zhong

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics, High Energy Physics - Phenomenology, Nuclear Theory
Abstract

Capturing low-energy electron antineutrinos on radioactive Ho-163 nuclei, which decay into Dy-163 via electron capture (EC), is a noteworthy opportunity to detect relic sterile antineutrinos. Such hypothetical particles are more or less implied by current experimental and cosmological data, and they might be a part of hot dark matter or a candidate for warm dark matter in the Universe. Using the isotope Ho-163 as a target and assuming reasonable active-sterile antineutrino mixing angles, we calculate the capture rate of relic electron antineutrinos against the corresponding EC-decay background in the presence of sterile antineutrinos at the sub-eV or keV mass scale. We show that the signature of hot or warm sterile antineutrino dark matter should in principle be observable, provided the target is big enough and the energy resolution is good enough., Comment: 16 pages, 6 figures, more discussions and references added. To appear in JCAP

Published
2011
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90. A Possible Detection of the Cosmic Antineutrino Background in the Presence of Flavor Effects

Author

Li, Y. F. and Xing, Zhi-zhong

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics, High Energy Physics - Phenomenology
Abstract

Lusignoli and Vignati have recently pointed out that it is in principle possible to directly detect the cosmic antineutrino background by using the rather stable isotope holmium-163 as a target, which can decay into dysprosium-163 via electron capture (EC) with a very small energy release. In this paper we calculate the rate of the relic antineutrino capture on holmium-163 nuclei against the corresponding EC decay rate by taking account of different neutrino mass hierarchies and reasonable values of theta_13. We show that such flavor effects are appreciable and even important in some cases, and stress that a calorimetric measurement of the cosmic antineutrino background might be feasible in the far future., Comment: 13 pages, 5 figures, revised version, accepted for publication in Phys. Lett. B

Published
2011
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91. Possible Capture of keV Sterile Neutrino Dark Matter on Radioactive beta-decaying Nuclei

Author

Li, Y. F. and Xing, Zhi-zhong

Subjects
High Energy Physics - Phenomenology, Astrophysics - Cosmology and Extragalactic Astrophysics, High Energy Physics - Experiment
Abstract

There exists an observed "desert" spanning six orders of magnitude between O(0.5) eV and O(0.5) MeV in the fermion mass spectrum. We argue that it might accommodate one or more keV sterile neutrinos as a natural candidate for warm dark matter. To illustrate this point of view, we simply assume that there is one keV sterile neutrino nu_4 and its flavor eigenstate nu_s weakly mixes with three active neutrinos. We clarify different active-sterile neutrino mixing factors for the radiative decay of nu_4 and beta decays in a self-consistent parametrization. A direct detection of this keV sterile neutrino dark matter in the laboratory is in principle possible since the nu_4 component of nu_e can leave a distinct imprint on the electron energy spectrum when it is captured on radioactive beta-decaying nuclei. We carry out an analysis of its signatures in the capture reactions nu_e + ^{3}H \to ^{3}He + e^- and nu_e + ^{106}Ru \to ^{106}Rh + e^- against the beta-decay backgrounds, and conclude that this experimental approach might not be hopeless in the long run., Comment: 14 pages, 3 figures, more discussions and references added. To appear in PLB

Published
2010
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92. Direct Detection of the Cosmic Neutrino Background Including Light Sterile Neutrinos

Author

Li, Y. F., Luo, Shu, and Xing, Zhi-zhong

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract

Current cosmological data drop an interesting hint about the existence of sub-eV sterile neutrinos, which should be a part of the cosmic neutrino background (C$\nu$B). We point out that such light sterile neutrinos may leave a distinct imprint on the electron energy spectrum in the capture of relic electron neutrinos by means of radioactive beta-decaying nuclei. We examine possible signals of sterile neutrinos relative to active neutrinos, characterized by their masses and sensitive to their number densities, in the reaction $\nu^{}_e + ~^3{\rm H} \to ~^3{\rm He} + e^-$ against the corresponding tritium beta decay. We stress that this kind of direct laboratory detection of the C$\nu$B and its sterile component might not be hopeless in the long term., Comment: Minor changes. Accepted for publication in Phys. Lett. B

Published
2010
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93. Corrections to Tribimaximal Mixing from Nondegenerate Phases

Author

Li, Y. F. and Liu, Q. Y.

Subjects
High Energy Physics - Phenomenology
Abstract

We propose a seesaw scenario that possible corrections to the tribimaximal pattern of lepton mixing are due to the small phase splitting of the right-handed neutrino mass matrix. we show that the small deviations can be expressed analytically in terms of two splitting parameters($\delta_1$ and $\delta_2$) in the leading order. The solar mixing angle $\theta_{12}$ favors a relatively smaller value compared to zero order value ($35.3^\circ$), and the Dirac type CP phase $\delta$ chooses a nearly maximal one. The two Majorana type CP phases $\rho$ and $\sigma$ turn out to be a nearly linear dependence. Also a normal hierarchy neutrino mass spectrum is favored due to the stability of perturbation calculations., Comment: 19 pages 6 figures, Accepted by Mod. Phy. Lett. A

Published
2009
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94. Matter Effects in Active-Sterile Solar Neutrino Oscillations

Author

Giunti, C. and Li, Y. F.

Subjects
High Energy Physics - Phenomenology
Abstract

The matter effects for solar neutrino oscillations are studied in a general scheme with an arbitrary number of sterile neutrinos, without any constraint on the mixing, assuming only a realistic hierarchy of neutrino squared-mass differences in which the smallest squared-mass difference is effective in solar neutrino oscillations. The validity of the analytic results are illustrated with a numerical solution of the evolution equation in three examples of the possible mixing matrix in the simplest case of four-neutrino mixing., Comment: 26 pages. Final version published in Phys. Rev. D80 (2009) 113007

Published
2009
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95. A Paradox on Quantum Field Theory of Neutrino Mixing and Oscillations

Author

Li, Y. F. and Liu, Q. Y.

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

Neutrino mixing and oscillations in quantum field theory framework had been studied before, which shew that the Fock space of flavor states is unitarily inequivalent to that of mass states (inequivalent vacua model). A paradox emerges when we use these neutrino weak states to calculate the amplitude of $W$ boson decay. The branching ratio of W(+) -> e(+) + nu_mu to W(+) -> e(+) + nu_e is approximately at the order of O({m_i^2}/{k^2}). The existence of flavor changing currents contradicts to the Hamiltonian we started from, and the usual knowledge about weak processes. Also, negative energy neutrinos (or violating the principle of energy conservation) appear in this framework. We discuss possible reasons for the appearance of this paradox., Comment: 15 pages, revised version: oscillation effect is separated

Published
2006
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