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179 results on '"Cherwinka, JJ"'

1. The data acquisition system of the LZ dark matter detector: FADR

Author: Aalbers, J, Akerib, DS, Al Musalhi, AK, Alder, F, Amarasinghe, CS, Ames, A, Anderson, TJ, Angelides, N, Araújo, HM, Armstrong, JE, Arthurs, M, Baker, A, Balashov, S, Bang, J, Barillier, EE, Bargemann, JW, Beattie, K, Benson, T, Bhatti, A, Biekert, A, Biesiadzinski, TP, Birch, HJ, Bishop, E, Blockinger, GM, Boxer, B, Brew, CAJ, Brás, P, Buckley, JH, Burdin, S, Buuck, M, Carmona-Benitez, MC, Carter, M, Chawla, A, Chen, H, Cherwinka, JJ, Chin, YT, Chott, NI, Converse, MV, Cottle, A, Cox, G, Curran, D, Dahl, CE, David, A, Delgaudio, J, Dey, S, de Viveiros, L, Di Felice, L, Dimino, T, Ding, C, Dobson, JEY, Druszkiewicz, E, Eriksen, SR, Fan, A, Fearon, NM, Fieldhouse, N, Fiorucci, S, Flaecher, H, Fraser, ED, Fruth, TMA, Gaitskell, RJ, Geffre, A, Gelfand, R, Genovesi, J, Ghag, C, Gibbons, R, Gokhale, S, Green, J, van der Grinten, MGD, Haiston, JJ, Hall, CR, Han, S, Hartigan-O’Connor, E, Haselschwardt, SJ, Hernandez, MA, Hertel, SA, Heuermann, G, Homenides, GJ, Horn, M, Huang, DQ, Hunt, D, Jacquet, E, James, RS, Johnson, J, Kaboth, AC, Kamaha, AC, Kannichankandy, M, Khaitan, D, Khazov, A, Khurana, I, Kim, J, Kim, YD, Kingston, J, Kirk, R, Kodroff, D, Korley, L, Korolkova, EV, Koyuncu, M, Kraus, H, Kravitz, S, and Kreczko, L
Subjects: Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, Networking and Information Technology R&D (NITRD), Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Other Physical Sciences, Nuclear & Particles Physics, Nuclear and plasma physics
Abstract: The Data Acquisition System (DAQ) for the LUX-ZEPLIN (LZ) dark matter detector is described. The signals from 745 PMTs, distributed across three subsystems, are sampled with 100-MHz 32-channel digitizers (DDC-32s). A basic waveform analysis is carried out on the on-board Field Programmable Gate Arrays (FPGAs) to extract information about the observed scintillation and electroluminescence signals. This information is used to determine if the digitized waveforms should be preserved for offline analysis. The system is designed around the Kintex-7 FPGA. In addition to digitizing the PMT signals and providing basic event selection in real time, the flexibility provided by the use of FPGAs allows us to monitor the performance of the detector and the DAQ in parallel to normal data acquisition. The hardware and software/firmware of this FPGA-based Architecture for Data acquisition and Realtime monitoring (FADR) are discussed and performance measurements are described.
Published: 2024

2. The design, implementation, and performance of the LZ calibration systems

Author: Aalbers, J, Akerib, DS, Al Musalhi, AK, Alder, F, Amarasinghe, CS, Ames, A, Anderson, TJ, Angelides, N, Araújo, HM, Armstrong, JE, Arthurs, M, Baker, A, Balashov, S, Bang, J, Barillier, EE, Bargemann, JW, Beattie, K, Benson, T, Bhatti, A, Biekert, A, Biesiadzinski, TP, Birch, HJ, Bishop, E, Blockinger, GM, Boxer, B, Brew, CAJ, Brás, P, Burdin, S, Buuck, M, Carmona-Benitez, MC, Carter, M, Chawla, A, Chen, H, Cherwinka, JJ, Chin, YT, Chott, NI, Converse, MV, Cottle, A, Cox, G, Curran, D, Dahl, CE, David, A, Delgaudio, J, Dey, S, de Viveiros, L, Di Felice, L, Ding, C, Dobson, JEY, Druszkiewicz, E, Eriksen, SR, Fan, A, Fearon, NM, Fieldhouse, N, Fiorucci, S, Flaecher, H, Fraser, ED, Fruth, TMA, Gaitskell, RJ, Geffre, A, Genovesi, J, Ghag, C, Gibbons, R, Gokhale, S, Green, J, van der Grinten, MGD, Haiston, JJ, Hall, CR, Han, S, Hartigan-O'Connor, E, Haselschwardt, SJ, Hernandez, MA, Hertel, SA, Heuermann, G, Homenides, GJ, Horn, M, Huang, DQ, Hunt, D, Jacquet, E, James, RS, Johnson, J, Kaboth, AC, Kamaha, AC, Kannichankandy, M, Khaitan, D, Khazov, A, Khurana, I, Kim, J, Kim, YD, Kingston, J, Kirk, R, Kodroff, D, Korley, L, Korolkova, EV, Kraus, H, Kravitz, S, Kreczko, L, Kudryavtsev, VA, Leonard, DS, Lesko, KT, and Levy, C
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Engineering, Nuclear & Particles Physics, Physical sciences
Abstract: LUX-ZEPLIN (LZ) is a tonne-scale experiment searching for direct dark matter interactions and other rare events. It is located at the Sanford Underground Research Facility (SURF) in Lead, South Dakota, USA. The core of the LZ detector is a dual-phase xenon time projection chamber (TPC), designed with the primary goal of detecting Weakly Interacting Massive Particles (WIMPs) via their induced low energy nuclear recoils. Surrounding the TPC, two veto detectors immersed in an ultra-pure water tank enable reducing background events to enhance the discovery potential. Intricate calibration systems are purposely designed to precisely understand the responses of these three detector volumes to various types of particle interactions and to demonstrate LZ’s ability to discriminate between signals and backgrounds. In this paper, we present a comprehensive discussion of the key features, requirements, and performance of the LZ calibration systems, which play a crucial role in enabling LZ’s WIMP-search and its broad science program. The thorough description of these calibration systems, with an emphasis on their novel aspects, is valuable for future calibration efforts in direct dark matter and other rare-event search experiments.
Published: 2024

3. New constraints on ultraheavy dark matter from the LZ experiment

Author: Aalbers, J, Akerib, DS, Al Musalhi, AK, Alder, F, Amarasinghe, CS, Ames, A, Anderson, TJ, Angelides, N, Araújo, HM, Armstrong, JE, Arthurs, M, Baker, A, Balashov, S, Bang, J, Barillier, EE, Bargemann, JW, Baxter, A, Beattie, K, Benson, T, Bhatti, A, Biekert, A, Biesiadzinski, TP, Birch, HJ, Bishop, EJ, Blockinger, GM, Boxer, B, Brew, CAJ, Brás, P, Burdin, S, Buuck, M, Carmona-Benitez, MC, Carter, M, Chawla, A, Chen, H, Cherwinka, JJ, Chin, YT, Chott, NI, Converse, MV, Cottle, A, Cox, G, Curran, D, Dahl, CE, David, A, Delgaudio, J, Dey, S, de Viveiros, L, Di Felice, L, Ding, C, Dobson, JEY, Druszkiewicz, E, Eriksen, SR, Fan, A, Fearon, NM, Fiorucci, S, Flaecher, H, Fraser, ED, Fruth, TMA, Gaitskell, RJ, Geffre, A, Genovesi, J, Ghag, C, Gibbons, R, Gokhale, S, Green, J, van der Grinten, MGD, Haiston, JH, Hall, CR, Han, S, Hartigan-O’Connor, E, Haselschwardt, SJ, Hernandez, MA, Hertel, SA, Heuermann, G, Homenides, GJ, Horn, M, Huang, DQ, Hunt, D, Ignarra, CM, Jacquet, E, James, RS, Johnson, J, Kaboth, AC, Kamaha, AC, Kannichankandy, M, Khaitan, D, Khazov, A, Khurana, I, Kim, J, Kingston, J, Kirk, R, Kodroff, D, Korley, L, Korolkova, EV, Kraus, H, Kravitz, S, Kreczko, L, Krikler, B, Kudryavtsev, VA, Lee, J, and Leonard, DS
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences
Abstract: Searches for dark matter with liquid xenon time projection chamber experiments have traditionally focused on the region of the parameter space that is characteristic of weakly interacting massive particles, ranging from a few GeV/c2 to a few TeV/c2. Models of dark matter with a mass much heavier than this are well motivated by early production mechanisms different from the standard thermal freeze-out, but they have generally been less explored experimentally. In this work, we present a reanalysis of the first science run of the LZ experiment, with an exposure of 0.9 tonne×yr, to search for ultraheavy particle dark matter. The signal topology consists of multiple energy deposits in the active region of the detector forming a straight line, from which the velocity of the incoming particle can be reconstructed on an event-by-event basis. Zero events with this topology were observed after applying the data selection calibrated on a simulated sample of signal-like events. New experimental constraints are derived, which rule out previously unexplored regions of the dark matter parameter space of spin-independent interactions beyond a mass of 1017 GeV/c2.
Published: 2024

4. First constraints on WIMP-nucleon effective field theory couplings in an extended energy region from LUX-ZEPLIN

Author: Aalbers, J, Akerib, DS, Al Musalhi, AK, Alder, F, Amarasinghe, CS, Ames, A, Anderson, TJ, Angelides, N, Araújo, HM, Armstrong, JE, Arthurs, M, Baker, A, Balashov, S, Bang, J, Bargemann, JW, Baxter, A, Beattie, K, Benson, T, Bhatti, A, Biekert, A, Biesiadzinski, TP, Birch, HJ, Bishop, E, Blockinger, GM, Boxer, B, Brew, CAJ, Brás, P, Burdin, S, Buuck, M, Carmona-Benitez, MC, Carter, M, Chawla, A, Chen, H, Cherwinka, JJ, Chott, NI, Converse, MV, Cottle, A, Cox, G, Curran, D, Dahl, CE, David, A, Delgaudio, J, Dey, S, de Viveiros, L, Ding, C, Dobson, JEY, Druszkiewicz, E, Eriksen, SR, Fan, A, Fearon, NM, Fiorucci, S, Flaecher, H, Fraser, ED, Fruth, TMA, Gaitskell, RJ, Geffre, A, Genovesi, J, Ghag, C, Gibbons, R, Gokhale, S, Green, J, van der Grinten, MGD, Hall, CR, Han, S, Hartigan-O’Connor, E, Haselschwardt, SJ, Hernandez, MA, Hertel, SA, Heuermann, G, Homenides, GJ, Horn, M, Huang, DQ, Hunt, D, Ignarra, CM, Jacquet, E, James, RS, Johnson, J, Kaboth, AC, Kamaha, AC, Khaitan, D, Khazov, A, Khurana, I, Kim, J, Kingston, J, Kirk, R, Kodroff, D, Korley, L, Korolkova, EV, Kraus, H, Kravitz, S, Kreczko, L, Krikler, B, Kudryavtsev, VA, Lee, J, Leonard, DS, Lesko, KT, Levy, C, Lin, J, Lindote, A, and Linehan, R
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Affordable and Clean Energy
Abstract: Following the first science results of the LUX-ZEPLIN (LZ) experiment, a dual-phase xenon time projection chamber operating from the Sanford Underground Research Facility in Lead, South Dakota, USA, we report the initial limits on a model-independent nonrelativistic effective field theory describing the complete set of possible interactions of a weakly interacting massive particle (WIMP) with a nucleon. These results utilize the same 5.5 t fiducial mass and 60 live days of exposure collected for the LZ spin-independent and spin-dependent analyses while extending the upper limit of the energy region of interest by a factor of 7.5 to 270 keV. No significant excess in this high energy region is observed. Using a profile-likelihood ratio analysis, we report 90% confidence level exclusion limits on the coupling of each individual nonrelativistic WIMP-nucleon operator for both elastic and inelastic interactions in the isoscalar and isovector bases.
Published: 2024

5. Search for new physics in low-energy electron recoils from the first LZ exposure

Author: Aalbers, J, Akerib, DS, Al Musalhi, AK, Alder, F, Amarasinghe, CS, Ames, A, Anderson, TJ, Angelides, N, Araújo, HM, Armstrong, JE, Arthurs, M, Baker, A, Balashov, S, Bang, J, Bargemann, JW, Baxter, A, Beattie, K, Beltrame, P, Benson, T, Bhatti, A, Biekert, A, Biesiadzinski, TP, Birch, HJ, Blockinger, GM, Boxer, B, Brew, CAJ, Brás, P, Burdin, S, Buuck, M, Carmona-Benitez, MC, Chan, C, Chawla, A, Chen, H, Cherwinka, JJ, Chott, NI, Converse, MV, Cottle, A, Cox, G, Curran, D, Dahl, CE, David, A, Delgaudio, J, Dey, S, de Viveiros, L, Ding, C, Dobson, JEY, Druszkiewicz, E, Eriksen, SR, Fan, A, Fearon, NM, Fiorucci, S, Flaecher, H, Fraser, ED, Fruth, TMA, Gaitskell, RJ, Geffre, A, Genovesi, J, Ghag, C, Gibbons, R, Gokhale, S, Green, J, van der Grinten, MGD, Hall, CR, Han, S, Hartigan-O’Connor, E, Haselschwardt, SJ, Huang, DQ, Hertel, SA, Heuermann, G, Horn, M, Hunt, D, Ignarra, CM, Jahangir, O, James, RS, Johnson, J, Kaboth, AC, Kamaha, AC, Khaitan, D, Khazov, A, Khurana, I, Kim, J, Kingston, J, Kirk, R, Kodroff, D, Korley, L, Korolkova, EV, Kraus, H, Kravitz, S, Kreczko, L, Krikler, B, Kudryavtsev, VA, Leason, EA, Lee, J, Leonard, DS, Lesko, KT, Levy, C, Lin, J, Lindote, A, Linehan, R, and Lippincott, WH
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences
Abstract: The LUX-ZEPLIN (LZ) experiment is a dark matter detector centered on a dual-phase xenon time projection chamber. We report searches for new physics appearing through few-keV-scale electron recoils, using the experiment's first exposure of 60 live days and a fiducial mass of 5.5 t. The data are found to be consistent with a background-only hypothesis, and limits are set on models for new physics including solar axion electron coupling, solar neutrino magnetic moment and millicharge, and electron couplings to galactic axionlike particles and hidden photons. Similar limits are set on weakly interacting massive particle (WIMP) dark matter producing signals through ionized atomic states from the Migdal effect.
Published: 2023

6. First Dark Matter Search Results from the LUX-ZEPLIN (LZ) Experiment

Author: Aalbers, J, Akerib, DS, Akerlof, CW, Al Musalhi, AK, Alder, F, Alqahtani, A, Alsum, SK, Amarasinghe, CS, Ames, A, Anderson, TJ, Angelides, N, Araújo, HM, Armstrong, JE, Arthurs, M, Azadi, S, Bailey, AJ, Baker, A, Balajthy, J, Balashov, S, Bang, J, Bargemann, JW, Barry, MJ, Barthel, J, Bauer, D, Baxter, A, Beattie, K, Belle, J, Beltrame, P, Bensinger, J, Benson, T, Bernard, EP, Bhatti, A, Biekert, A, Biesiadzinski, TP, Birch, HJ, Birrittella, B, Blockinger, GM, Boast, KE, Boxer, B, Bramante, R, Brew, CAJ, Brás, P, Buckley, JH, Bugaev, VV, Burdin, S, Busenitz, JK, Buuck, M, Cabrita, R, Carels, C, Carlsmith, DL, Carlson, B, Carmona-Benitez, MC, Cascella, M, Chan, C, Chawla, A, Chen, H, Cherwinka, JJ, Chott, NI, Cole, A, Coleman, J, Converse, MV, Cottle, A, Cox, G, Craddock, WW, Creaner, O, Curran, D, Currie, A, Cutter, JE, Dahl, CE, David, A, Davis, J, Davison, TJR, Delgaudio, J, Dey, S, de Viveiros, L, Dobi, A, Dobson, JEY, Druszkiewicz, E, Dushkin, A, Edberg, TK, Edwards, WR, Elnimr, MM, Emmet, WT, Eriksen, SR, Faham, CH, Fan, A, Fayer, S, Fearon, NM, Fiorucci, S, Flaecher, H, Ford, P, Francis, VB, Fraser, ED, Fruth, T, Gaitskell, RJ, Gantos, NJ, Garcia, D, Geffre, A, Gehman, VM, and Genovesi, J
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, LUX-ZEPLIN Collaboration, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract: The LUX-ZEPLIN experiment is a dark matter detector centered on a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility in Lead, South Dakota, USA. This Letter reports results from LUX-ZEPLIN's first search for weakly interacting massive particles (WIMPs) with an exposure of 60 live days using a fiducial mass of 5.5 t. A profile-likelihood ratio analysis shows the data to be consistent with a background-only hypothesis, setting new limits on spin-independent WIMP-nucleon, spin-dependent WIMP-neutron, and spin-dependent WIMP-proton cross sections for WIMP masses above 9 GeV/c^{2}. The most stringent limit is set for spin-independent scattering at 36 GeV/c^{2}, rejecting cross sections above 9.2×10^{-48} cm at the 90% confidence level.
Published: 2023

7. Improved Measurement of the Evolution of the Reactor Antineutrino Flux and Spectrum at Daya Bay

Author: An, FP, Bai, WD, Balantekin, AB, Bishai, M, Blyth, S, Cao, GF, Cao, J, Chang, JF, Chang, Y, Chen, HS, Chen, HY, Chen, SM, Chen, Y, Chen, YX, Cheng, J, Cheng, Y-C, Cheng, ZK, Cherwinka, JJ, Chu, MC, Cummings, JP, Dalager, O, Deng, FS, Ding, YY, Diwan, MV, Dohnal, T, Dolzhikov, D, Dove, J, Dugas, KV, Duyang, HY, Dwyer, DA, Gallo, JP, Gonchar, M, Gong, GH, Gong, H, Gu, WQ, Guo, JY, Guo, L, Guo, XH, Guo, YH, Guo, Z, Hackenburg, RW, Han, Y, Hans, S, He, M, Heeger, KM, Heng, YK, Hor, YK, Hsiung, YB, Hu, BZ, Hu, JR, Hu, T, Hu, ZJ, Huang, HX, Huang, JH, Huang, XT, Huang, YB, Huber, P, Jaffe, DE, Jen, KL, Ji, XL, Ji, XP, Johnson, RA, Jones, D, Kang, L, Kettell, SH, Kohn, S, Kramer, M, Langford, TJ, Lee, J, Lee, JHC, Lei, RT, Leitner, R, Leung, JKC, Li, F, Li, HL, Li, JJ, Li, QJ, Li, RH, Li, S, Li, SC, Li, WD, Li, XN, Li, XQ, Li, YF, Li, ZB, Liang, H, Lin, CJ, Lin, GL, Lin, S, Ling, JJ, Link, JM, Littenberg, L, Littlejohn, BR, Liu, JC, Liu, JL, Liu, JX, Lu, C, Lu, HQ, and Luk, KB
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Nuclear Reactors, Uranium, Daya Bay Collaboration, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract: Reactor neutrino experiments play a crucial role in advancing our knowledge of neutrinos. In this Letter, the evolution of the flux and spectrum as a function of the reactor isotopic content is reported in terms of the inverse-beta-decay yield at Daya Bay with 1958 days of data and improved systematic uncertainties. These measurements are compared with two signature model predictions: the Huber-Mueller model based on the conversion method and the SM2018 model based on the summation method. The measured average flux and spectrum, as well as the flux evolution with the ^{239}Pu isotopic fraction, are inconsistent with the predictions of the Huber-Mueller model. In contrast, the SM2018 model is shown to agree with the average flux and its evolution but fails to describe the energy spectrum. Altering the predicted inverse-beta-decay spectrum from ^{239}Pu fission does not improve the agreement with the measurement for either model. The models can be brought into better agreement with the measurements if either the predicted spectrum due to ^{235}U fission is changed or the predicted ^{235}U, ^{238}U, ^{239}Pu, and ^{241}Pu spectra are changed in equal measure.
Published: 2023

8. Precision Measurement of Reactor Antineutrino Oscillation at Kilometer-Scale Baselines by Daya Bay

Author: An, FP, Bai, WD, Balantekin, AB, Bishai, M, Blyth, S, Cao, GF, Cao, J, Chang, JF, Chang, Y, Chen, HS, Chen, HY, Chen, SM, Chen, Y, Chen, YX, Chen, ZY, Cheng, J, Cheng, ZK, Cherwinka, JJ, Chu, MC, Cummings, JP, Dalager, O, Deng, FS, Ding, YY, Ding, XY, Diwan, MV, Dohnal, T, Dolzhikov, D, Dove, J, Duyang, HY, Dwyer, DA, Gallo, JP, Gonchar, M, Gong, GH, Gong, H, Gu, WQ, Guo, JY, Guo, L, Guo, XH, Guo, YH, Guo, Z, Hackenburg, RW, Han, Y, Hans, S, He, M, Heeger, KM, Heng, YK, Hor, YK, Hsiung, YB, Hu, BZ, Hu, JR, Hu, T, Hu, ZJ, Huang, HX, Huang, JH, Huang, XT, Huang, YB, Huber, P, Jaffe, DE, Jen, KL, Ji, XL, Ji, XP, Johnson, RA, Jones, D, Kang, L, Kettell, SH, Kohn, S, Kramer, M, Langford, TJ, Lee, J, Lee, JHC, Lei, RT, Leitner, R, Leung, JKC, Li, F, Li, HL, Li, JJ, Li, QJ, Li, RH, Li, S, Li, SC, Li, WD, Li, XN, Li, XQ, Li, YF, Li, ZB, Liang, H, Lin, CJ, Lin, GL, Lin, S, Ling, JJ, Link, JM, Littenberg, L, Littlejohn, BR, Liu, JC, Liu, JL, Liu, JX, Lu, C, Lu, HQ, Luk, KB, and Z., B
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Daya Bay Collaboration, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract: We present a new determination of the smallest neutrino mixing angle θ_{13} and the mass-squared difference Δm_{32}^{2} using a final sample of 5.55×10^{6} inverse beta-decay (IBD) candidates with the final-state neutron captured on gadolinium. This sample is selected from the complete dataset obtained by the Daya Bay reactor neutrino experiment in 3158 days of operation. Compared to the previous Daya Bay results, selection of IBD candidates has been optimized, energy calibration refined, and treatment of backgrounds further improved. The resulting oscillation parameters are sin^{2}2θ_{13}=0.0851±0.0024, Δm_{32}^{2}=(2.466±0.060)×10^{-3} eV^{2} for the normal mass ordering or Δm_{32}^{2}=-(2.571±0.060)×10^{-3} eV^{2} for the inverted mass ordering.
Published: 2023

9. First Measurement of High-Energy Reactor Antineutrinos at Daya Bay

Author: An, FP, Bai, WD, Balantekin, AB, Bishai, M, Blyth, S, Cao, GF, Cao, J, Chang, JF, Chang, Y, Chen, HS, Chen, HY, Chen, SM, Chen, Y, Chen, YX, Cheng, J, Cheng, ZK, Cherwinka, JJ, Chu, MC, Cummings, JP, Dalager, O, Deng, FS, Ding, YY, Diwan, MV, Dohnal, T, Dolzhikov, D, Dove, J, Dwyer, DA, Gallo, JP, Gonchar, M, Gong, GH, Gong, H, Gu, WQ, Guo, JY, Guo, L, Guo, XH, Guo, YH, Guo, Z, Hackenburg, RW, Hans, S, He, M, Heeger, KM, Heng, YK, Hor, YK, Hsiung, YB, Hu, BZ, Hu, JR, Hu, T, Hu, ZJ, Huang, HX, Huang, JH, Huang, XT, Huang, YB, Huber, P, Jaffe, DE, Jen, KL, Ji, XL, Ji, XP, Johnson, RA, Jones, D, Kang, L, Kettell, SH, Kohn, S, Kramer, M, Langford, TJ, Lee, J, Lee, JHC, Lei, RT, Leitner, R, Leung, JKC, Li, F, Li, HL, Li, JJ, Li, QJ, Li, RH, Li, S, Li, SC, Li, WD, Li, XN, Li, XQ, Li, YF, Li, ZB, Liang, H, Lin, CJ, Lin, GL, Lin, S, Ling, JJ, Link, JM, Littenberg, L, Littlejohn, BR, Liu, JC, Liu, JL, Liu, JX, Lu, C, Lu, HQ, Luk, KB, Z., B, B., X, Y., X, Q., Y, and Mandujano, RC
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, Affordable and Clean Energy, Daya Bay Collaboration, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract: This Letter reports the first measurement of high-energy reactor antineutrinos at Daya Bay, with nearly 9000 inverse beta decay candidates in the prompt energy region of 8-12 MeV observed over 1958 days of data collection. A multivariate analysis is used to separate 2500 signal events from background statistically. The hypothesis of no reactor antineutrinos with neutrino energy above 10 MeV is rejected with a significance of 6.2 standard deviations. A 29% antineutrino flux deficit in the prompt energy region of 8-11 MeV is observed compared to a recent model prediction. We provide the unfolded antineutrino spectrum above 7 MeV as a data-based reference for other experiments. This result provides the first direct observation of the production of antineutrinos from several high-Q_{β} isotopes in commercial reactors.
Published: 2022

10. Design and production of the high voltage electrode grids and electron extraction region for the LZ dual-phase xenon time projection chamber

Author: Linehan, R, Mannino, RL, Fan, A, Ignarra, CM, Luitz, S, Skarpaas, K, Shutt, TA, Akerib, DS, Alsum, SK, Anderson, TJ, Araújo, HM, Arthurs, M, Auyeung, H, Bailey, AJ, Biesiadzinski, TP, Breidenbach, M, Cherwinka, JJ, Conley, RA, Genovesi, J, Gilchriese, MGD, Glaenzer, A, Gonda, TG, Hanzel, K, Hoff, MD, Ji, W, Kaboth, AC, Kravitz, S, Kurita, NR, Lambert, AR, Lesko, KT, Lorenzon, W, Majewski, PA, Miller, EH, Monzani, ME, Palladino, KJ, Ratcliff, BN, Saba, JS, Santone, D, Shutt, GW, Stifter, K, Szydagis, M, Tomás, A, Va’vra, J, Waldron, WL, Webb, RC, White, RG, Whitis, TJ, Wilson, K, and Wisniewski, WJ
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Xenon, TPC, HV, Electrode, Noble liquid, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Other Physical Sciences, Nuclear & Particles Physics, Nuclear and plasma physics
Abstract: The dual-phase xenon time projection chamber (TPC) is a powerful tool for direct-detection experiments searching for WIMP dark matter, other dark matter models, and neutrinoless double-beta decay. Successful operation of such a TPC is critically dependent on the ability to hold high electric fields in the bulk liquid, across the liquid surface, and in the gas. Careful design and construction of the electrodes used to establish these fields is therefore required. We present the design and production of the LUX-ZEPLIN (LZ) experiment's high-voltage electrodes, a set of four woven mesh wire grids. Grid design drivers are discussed, with emphasis placed on design of the electron extraction region. We follow this with a description of the grid production process and a discussion of steps taken to validate the LZ grids prior to integration into the TPC.
Published: 2022

11. Erratum to: The LUX-ZEPLIN (LZ) radioactivity and cleanliness control programs

Author: Akerib, DS, Akerlof, CW, Akimov, D Yu, Alquahtani, A, Alsum, SK, Anderson, TJ, Angelides, N, Araújo, HM, Arbuckle, A, Armstrong, JE, Arthurs, M, Auyeung, H, Aviles, S, Bai, X, Bailey, AJ, Balajthy, J, Balashov, S, Bang, J, Barry, MJ, Bauer, D, Bauer, P, Baxter, A, Belle, J, Beltrame, P, Bensinger, J, Benson, T, Bernard, EP, Bernstein, A, Bhatti, A, Biekert, A, Biesiadzinski, TP, Birch, HJ, Birrittella, B, Boast, KE, Bolozdynya, AI, Boulton, EM, Boxer, B, Bramante, R, Branson, S, Brás, P, Breidenbach, M, Brew, CAJ, Buckley, JH, Bugaev, VV, Bunker, R, Burdin, S, Busenitz, JK, Cabrita, R, Campbell, JS, Carels, C, Carlsmith, DL, Carlson, B, Carmona-Benitez, MC, Cascella, M, Chan, C, Cherwinka, JJ, Chiller, AA, Chiller, C, Chott, NI, Cole, A, Coleman, J, Colling, D, Conley, RA, Cottle, A, Coughlen, R, Cox, G, Craddock, WW, Curran, D, Currie, A, Cutter, JE, da Cunha, JP, Dahl, CE, Dardin, S, Dasu, S, Davis, J, Davison, TJR, de Viveiros, L, Decheine, N, Dobi, A, Dobson, JEY, Druszkiewicz, E, Dushkin, A, Edberg, TK, Edwards, WR, Edwards, BN, Edwards, J, Elnimr, MM, Emmet, WT, Eriksen, SR, Faham, CH, Fan, A, Fayer, S, Fiorucci, S, Flaecher, H, Florang, IM Fogarty, Ford, P, Francis, VB, Fraser, ED, Froborg, F, and Fruth, T
Subjects: Particle and High Energy Physics, Astronomical Sciences, Atomic, Molecular and Optical Physics, Physical Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Astronomical sciences, Atomic, molecular and optical physics, Particle and high energy physics
Abstract: The reference to the article is Manuscript ID EPJC-20-06-042 from the internal review perspective. The reference to the article as published, is: (Table presented.).
Published: 2022

12. Joint Determination of Reactor Antineutrino Spectra from U235 and Pu239 Fission by Daya Bay and PROSPECT

Author: An, FP, Andriamirado, M, Balantekin, AB, Band, HR, Bass, CD, Bergeron, DE, Berish, D, Bishai, M, Blyth, S, Bowden, NS, Bryan, CD, Cao, GF, Cao, J, Chang, JF, Chang, Y, Chen, HS, Chen, SM, Chen, Y, Chen, YX, Cheng, J, Cheng, ZK, Cherwinka, JJ, Chu, MC, Classen, T, Conant, AJ, Cummings, JP, Dalager, O, Deichert, G, Delgado, A, Deng, FS, Ding, YY, Diwan, MV, Dohnal, T, Dolinski, MJ, Dolzhikov, D, Dove, J, Dvořák, M, Dwyer, DA, Erickson, A, Foust, BT, Gaison, JK, Galindo-Uribarri, A, Gallo, JP, Gilbert, CE, Gonchar, M, Gong, GH, Gong, H, Grassi, M, Gu, WQ, Guo, JY, Guo, L, Guo, XH, Guo, YH, Guo, Z, Hackenburg, RW, Hans, S, Hansell, AB, He, M, Heeger, KM, Heffron, B, Heng, YK, Hor, YK, Hsiung, YB, Hu, BZ, Hu, JR, Hu, T, Hu, ZJ, Huang, HX, Huang, JH, Huang, XT, Huang, YB, Huber, P, Koblanski, J, Jaffe, DE, Jayakumar, S, Jen, KL, Ji, XL, Ji, XP, Johnson, RA, Jones, DC, Kang, L, Kettell, SH, Kohn, S, Kramer, M, Kyzylova, O, Lane, CE, Langford, TJ, LaRosa, J, Lee, J, Lee, JHC, Lei, RT, Leitner, R, Leung, JKC, Li, F, Li, HL, Li, JJ, Li, QJ, Li, RH, Li, S, and Li, SC
Subjects: Nuclear and Plasma Physics, Engineering, Synchrotrons and Accelerators, Physical Sciences, Daya Bay Collaboration, PROSPECT Collaboration, Mathematical Sciences, General Physics, Mathematical sciences, Physical sciences
Abstract: A joint determination of the reactor antineutrino spectra resulting from the fission of ^{235}U and ^{239}Pu has been carried out by the Daya Bay and PROSPECT Collaborations. This Letter reports the level of consistency of ^{235}U spectrum measurements from the two experiments and presents new results from a joint analysis of both data sets. The measurements are found to be consistent. The combined analysis reduces the degeneracy between the dominant ^{235}U and ^{239}Pu isotopes and improves the uncertainty of the ^{235}U spectral shape to about 3%. The ^{235}U and ^{239}Pu antineutrino energy spectra are unfolded from the jointly deconvolved reactor spectra using the Wiener-SVD unfolding method, providing a data-based reference for other reactor antineutrino experiments and other applications. This is the first measurement of the ^{235}U and ^{239}Pu spectra based on the combination of experiments at low- and highly enriched uranium reactors.
Published: 2022

13. Antineutrino energy spectrum unfolding based on the Daya Bay measurement and its applications * *Supported in part by the Ministry of Science and Technology of China, the U.S. Department of Energy, the Chinese Academy of Sciences, the CAS Center for Excellence in Particle Physics, the National Natural Science Foundation of China, the Guangdong provincial government, the Shenzhen municipal government, the China General Nuclear Power Group, the Research Grants Council of the Hong Kong Special Administrative Region of China, the Ministry of Education in TW, the U.S. National Science Foundation, the Ministry of Education, Youth, and Sports of the Czech Republic, the Charles University Research Centre UNCE, the Joint Institute of Nuclear Research in Dubna, Russia, the National Commission of Scientific and Technological Research of Chile

Author: An, FP, Balantekin, AB, Bishai, M, Blyth, S, Cao, GF, Cao, J, Chang, JF, Chang, Y, Chen, HS, Chen, SM, Chen, Y, Chen, YX, Cheng, J, Cheng, ZK, Cherwinka, JJ, Chu, MC, Cummings, JP, Dalager, O, Deng, FS, Ding, YY, Diwan, MV, Dohnal, T, Dolzhikov, D, Dove, J, Dvořák, M, Dwyer, DA, Gallo, JP, Gonchar, M, Gong, GH, Gong, H, Grassi, M, Gu, WQ, Guo, JY, Guo, L, Guo, XH, Guo, YH, Guo, Z, Hackenburg, RW, Hans, S, He, M, Heeger, KM, Heng, YK, Hor, YK, Hsiung, YB, Hu, BZ, Hu, JR, Hu, T, Hu, ZJ, Huang, HX, Huang, JH, Huang, XT, Huang, YB, Huber, P, Jaffe, DE, Jen, KL, Ji, XL, Ji, XP, Johnson, RA, Jones, D, Kang, L, Kettell, SH, Kohn, S, Kramer, M, Langford, TJ, Lee, J, Lee, JHC, Lei, RT, Leitner, R, Leung, JKC, Li, F, Li, HL, Li, JJ, Li, QJ, Li, RH, Li, S, Li, SC, Li, WD, Li, XN, Li, XQ, Li, YF, Li, ZB, Liang, H, Lin, CJ, Lin, GL, Lin, S, Ling, JJ, Link, JM, Littenberg, L, Littlejohn, BR, Liu, JC, Liu, JL, Liu, JX, Lu, C, Lu, HQ, Luk, KB, Z., B, B., X, Y., X, Q., Y, and Mandujano, RC
Subjects: Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, Affordable and Clean Energy, reactor antineutrino, energy spectrum, Daya Bay, application, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Atomic, molecular and optical physics, Particle and high energy physics
Abstract: The prediction of reactor antineutrino spectra will play a crucial role as reactor experiments enter the precision era. The positron energy spectrum of 3.5 million antineutrino inverse beta decay reactions observed by the Daya Bay experiment, in combination with the fission rates of fissile isotopes in the reactor, is used to extract the positron energy spectra resulting from the fission of specific isotopes. This information can be used to produce a precise, data-based prediction of the antineutrino energy spectrum in other reactor antineutrino experiments with different fission fractions than Daya Bay. The positron energy spectra are unfolded to obtain the antineutrino energy spectra by removing the contribution from detector response with the Wiener-SVD unfolding method. Consistent results are obtained with other unfolding methods. A technique to construct a data-based prediction of the reactor antineutrino energy spectrum is proposed and investigated. Given the reactor fission fractions, the technique can predict the energy spectrum to a 2% precision. In addition, we illustrate how to perform a rigorous comparison between the unfolded antineutrino spectrum and a theoretical model prediction that avoids the input model bias of the unfolding method.
Published: 2021

14. Design and production of the high voltage electrode grids and electron extraction region for the LZ dual-phase xenon time projection chamber

Author: Linehan, R, Mannino, RL, Fan, A, Ignarra, CM, Luitz, S, Skarpaas, K, Shutt, TA, Akerib, DS, Alsum, SK, Anderson, TJ, Araújo, HM, Arthurs, M, Auyeung, H, Bailey, AJ, Biesiadzinski, TP, Breidenbach, M, Cherwinka, JJ, Conley, RA, Genovesi, J, Gilchriese, MGD, Glaenzer, A, Gonda, TG, Hanzel, K, Hoff, MD, Ji, W, Kaboth, AC, Kravitz, S, Kurita, NR, Lambert, AR, Lesko, KT, Lorenzon, W, Majewski, PA, Miller, EH, Monzani, ME, Palladino, KJ, Ratcliff, BN, Saba, JS, Santone, D, Shutt, GW, Stifter, K, Szydagis, M, Tomás, A, Va'vra, J, Waldron, WL, Webb, RC, White, RG, Whitis, TJ, Wilson, K, and Wisniewski, WJ
Subjects: physics.ins-det, astro-ph.IM, hep-ex
Abstract: The dual-phase xenon time projection chamber (TPC) is a powerful tool fordirect-detection experiments searching for WIMP dark matter, other dark mattermodels, and neutrinoless double-beta decay. Successful operation of such a TPCis critically dependent on the ability to hold high electric fields in the bulkliquid, across the liquid surface, and in the gas. Careful design andconstruction of the electrodes used to establish these fields is thereforerequired. We present the design and production of the LUX-ZEPLIN (LZ)experiment's high-voltage electrodes, a set of four woven mesh wire grids. Griddesign drivers are discussed, with emphasis placed on design of the electronextraction region. We follow this with a description of the grid productionprocess and a discussion of steps taken to validate the LZ grids prior tointegration into the TPC.
Published: 2021

15. Search for electron-Antineutrinos associated with gravitational-wave events GW150914, GW151012, GW151226, GW170104, GW170608, GW170814, and GW170817 at Daya Bay

Author: An, FP, Balantekin, AB, Band, HR, Bishai, M, Blyth, S, Cao, GF, Cao, J, Chang, JF, Chang, Y, Chen, HS, Chen, SM, Chen, Y, Chen, YX, Cheng, J, Cheng, ZK, Cherwinka, JJ, Chu, MC, Cummings, JP, Dalager, O, Deng, FS, Ding, YY, Diwan, MV, Dohnal, T, Dove, J, Dvořák, M, Dwyer, DA, Gallo, JP, Gonchar, M, Gong, GH, Gong, H, Gu, WQ, Guo, JY, Guo, L, Guo, XH, Guo, YH, Guo, Z, Hackenburg, RW, Hans, S, He, M, Heeger, KM, Heng, YK, Higuera, A, Hor, YK, Hsiung, YB, Hu, BZ, Hu, JR, Hu, T, Hu, ZJ, Huang, HX, Huang, XT, Huang, YB, Huber, P, Jaffe, DE, Jen, KL, Ji, XL, Ji, XP, Johnson, RA, Jones, D, Kang, L, Kettell, SH, Kohn, S, Kramer, M, Langford, TJ, Lee, J, Lee, JHC, Lei, RT, Leitner, R, Leung, JKC, Li, F, Li, JJ, Li, QJ, Li, S, Li, SC, Li, WD, Li, XN, Li, XQ, Li, YF, Li, ZB, Liang, H, Lin, CJ, Lin, GL, Lin, S, Ling, JJ, Link, JM, Littenberg, L, Littlejohn, BR, Liu, JC, Liu, JL, Lu, C, Lu, HQ, Lu, JS, Luk, KB, Ma, XB, Ma, XY, Ma, YQ, Marshall, C, Martinez Caicedo, DA, McDonald, KT, McKeown, RD, and Meng, Y
Subjects: gravitational waves, electron-antineutrinos, fluence, upper limit, astro-ph.HE, hep-ex, physics.ins-det, Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract: The establishment of a possible connection between neutrino emission and gravitational-wave (GW) bursts is important to our understanding of the physical processes that occur when black holes or neutron stars merge. In the Daya Bay experiment, using the data collected from December 2011 to August 2017, a search was performed for electron-Antineutrino signals that coincided with detected GW events, including GW150914, GW151012, GW151226, GW170104, GW170608, GW170814, and GW170817. We used three time windows of 10, 500, and 1000 s relative to the occurrence of the GW events and a neutrino energy range of 1.8 to 100 MeV to search for correlated neutrino candidates. The detected electron-Antineutrino candidates were consistent with the expected background rates for all the three time windows. Assuming monochromatic spectra, we found upper limits (90% confidence level) of the electron-Antineutrino fluence of (1.13-2.44)×1011 cm-2 at 5 MeV to 8.0×107 cm-2 at 100 MeV for the three time windows. Under the assumption of a Fermi-Dirac spectrum, the upper limits were found to be (5.4-7.0)×109 cm-2 for the three time windows.
Published: 2021

16. Antineutrino Energy Spectrum Unfolding Based on the Daya Bay Measurement and Its Applications

Author: collaboration, Daya Bay, An, FP, Balantekin, AB, Band, HR, Bishai, M, Blyth, S, Cao, GF, Cao, J, Chang, JF, Chang, Y, Chen, HS, Chen, SM, Chen, Y, Chen, YX, Cheng, J, Cheng, ZK, Cherwinka, JJ, Chu, MC, Cummings, JP, Dalager, O, Deng, FS, Ding, YY, Diwan, MV, Dohnal, T, Dove, J, Dvorak, M, Dwyer, DA, Gallo, JP, Gonchar, M, Gong, GH, Gong, H, Gu, WQ, Guo, JY, Guo, L, Guo, XH, Guo, YH, Guo, Z, Hackenburg, RW, Hans, S, He, M, Heeger, KM, Heng, YK, Higuera, A, Hor, YK, Hsiung, YB, Hu, BZ, Hu, JR, Hu, T, Hu, ZJ, Huang, HX, Huang, XT, Huang, YB, Huber, P, Jaffe, DE, Jen, KL, Ji, XL, Ji, XP, Johnson, RA, Jones, D, Kang, L, Kettell, SH, Kohn, S, Kramer, M, Langford, TJ, Lee, J, Lee, JHC, Lei, RT, Leitner, R, Leung, JKC, Li, F, Li, JJ, Li, QJ, Li, S, Li, SC, Li, WD, Li, XN, Li, XQ, Li, YF, Li, ZB, Liang, H, Lin, CJ, Lin, GL, Lin, S, Ling, JJ, Link, JM, Littenberg, L, Littlejohn, BR, Liu, JC, Liu, JL, Lu, C, Lu, HQ, Lu, JS, Luk, KB, Ma, XB, Ma, XY, Ma, YQ, Marshall, C, Caicedo, DA Martinez, McDonald, KT, and McKeown, RD
Subjects: hep-ex, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Atomic, molecular and optical physics, Particle and high energy physics
Abstract: The prediction of reactor antineutrino spectra will play a crucial role asreactor experiments enter the precision era. The positron energy spectrum of3.5 million antineutrino inverse beta decay reactions observed by the Daya Bayexperiment, in combination with the fission rates of fissile isotopes in thereactor, is used to extract the positron energy spectra resulting from thefission of specific isotopes. This information can be used to produce aprecise, data-based prediction of the antineutrino energy spectrum in otherreactor antineutrino experiments with different fission fractions than DayaBay. The positron energy spectra are unfolded to obtain the antineutrino energyspectra by removing the contribution from detector response with the Wiener-SVDunfolding method. Consistent results are obtained with other unfolding methods.A technique to construct a data-based prediction of the reactor antineutrinoenergy spectrum is proposed and investigated. Given the reactor fissionfractions, the technique can predict the energy spectrum to a 2% precision. Inaddition, we illustrate how to perform a rigorous comparison between theunfolded antineutrino spectrum and a theoretical model prediction that avoidsthe input model bias of the unfolding method.
Published: 2021

17. Optimization of the JUNO liquid scintillator composition using a Daya Bay antineutrino detector

Author: Abusleme, A, Adam, T, Ahmad, S, Aiello, S, Akram, M, Ali, N, An, FP, An, GP, An, Q, Andronico, G, Anfimov, N, Antonelli, V, Antoshkina, T, Asavapibhop, B, de André, JPAM, Babic, A, Balantekin, AB, Baldini, W, Baldoncini, M, Band, HR, Barresi, A, Baussan, E, Bellato, M, Bernieri, E, Biare, D, Birkenfeld, T, Bishai, M, Blin, S, Blum, D, Blyth, S, Bordereau, C, Brigatti, A, Brugnera, R, Budano, A, Burgbacher, P, Buscemi, M, Bussino, S, Busto, J, Butorov, I, Cabrera, A, Cai, H, Cai, X, Cai, YK, Cai, ZY, Cammi, A, Campeny, A, Cao, CY, Cao, GF, Cao, J, Caruso, R, Cerna, C, Chang, JF, Chang, Y, Chen, HS, Chen, PA, Chen, PP, Chen, SM, Chen, SJ, Chen, XR, Chen, YW, Chen, YX, Chen, Y, Chen, Z, Cheng, J, Cheng, YP, Cheng, ZK, Chepurnov, A, Cherwinka, JJ, Chiarello, F, Chiesa, D, Chimenti, P, Chu, MC, Chukanov, A, Chuvashova, A, Clementi, C, Clerbaux, B, Di Lorenzo, S Conforti, Corti, D, Costa, S, Dal Corso, F, Cummings, JP, Dalager, O, De La Taille, C, Deng, FS, Deng, JW, Deng, Z, Deng, ZY, Depnering, W, Diaz, M, Ding, XF, Ding, YY, Dirgantara, B, Dmitrievsky, S, Diwan, MV, Dohnal, T, Donchenko, G, Dong, JM, Dornic, D, Doroshkevich, E, and Dove, J
Subjects: Nuclear and Plasma Physics, Physical Sciences, Neutrino, Liquid scintillator, Light yield, physics.ins-det, hep-ex, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Other Physical Sciences, Nuclear & Particles Physics, Nuclear and plasma physics
Abstract: To maximize the light yield of the liquid scintillator (LS) for the Jiangmen Underground Neutrino Observatory (JUNO), a 20 t LS sample was produced in a pilot plant at Daya Bay. The optical properties of the new LS in various compositions were studied by replacing the gadolinium-loaded LS in one antineutrino detector. The concentrations of the fluor, PPO, and the wavelength shifter, bis-MSB, were increased in 12 steps from 0.5 g/L and
Published: 2021

18. The LUX-ZEPLIN (LZ) radioactivity and cleanliness control programs

Author: Akerib, DS, Akerlof, CW, Akimov, D Yu, Alquahtani, A, Alsum, SK, Anderson, TJ, Angelides, N, Araújo, HM, Arbuckle, A, Armstrong, JE, Arthurs, M, Auyeung, H, Aviles, S, Bai, X, Bailey, AJ, Balajthy, J, Balashov, S, Bang, J, Barry, MJ, Bauer, D, Bauer, P, Baxter, A, Belle, J, Beltrame, P, Bensinger, J, Benson, T, Bernard, EP, Bernstein, A, Bhatti, A, Biekert, A, Biesiadzinski, TP, Birch, HJ, Birrittella, B, Boast, KE, Bolozdynya, AI, Boulton, EM, Boxer, B, Bramante, R, Branson, S, Brás, P, Breidenbach, M, Brew, CAJ, Buckley, JH, Bugaev, VV, Bunker, R, Burdin, S, Busenitz, JK, Cabrita, R, Campbell, JS, Carels, C, Carlsmith, DL, Carlson, B, Carmona-Benitez, MC, Cascella, M, Chan, C, Cherwinka, JJ, Chiller, AA, Chiller, C, Chott, NI, Cole, A, Coleman, J, Colling, D, Conley, RA, Cottle, A, Coughlen, R, Cox, G, Craddock, WW, Curran, D, Currie, A, Cutter, JE, da Cunha, JP, Dahl, CE, Dardin, S, Dasu, S, Davis, J, Davison, TJR, de Viveiros, L, Decheine, N, Dobi, A, Dobson, JEY, Druszkiewicz, E, Dushkin, A, Edberg, TK, Edwards, WR, Edwards, BN, Edwards, J, Elnimr, MM, Emmet, WT, Eriksen, SR, Faham, CH, Fan, A, Fayer, S, Fiorucci, S, Flaecher, H, Florang, IM Fogarty, Ford, P, Francis, VB, Fraser, ED, Froborg, F, and Fruth, T
Subjects: Nuclear and Plasma Physics, Physical Sciences, physics.ins-det, hep-ex, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Astronomical sciences, Atomic, molecular and optical physics, Particle and high energy physics
Abstract: LUX-ZEPLIN (LZ) is a second-generation direct dark matter experiment with spin-independent WIMP-nucleon scattering sensitivity above 1.4×10-48cm2 for a WIMP mass of 40GeV/c2 and a 1000days exposure. LZ achieves this sensitivity through a combination of a large 5.6t fiducial volume, active inner and outer veto systems, and radio-pure construction using materials with inherently low radioactivity content. The LZ collaboration performed an extensive radioassay campaign over a period of six years to inform material selection for construction and provide an input to the experimental background model against which any possible signal excess may be evaluated. The campaign and its results are described in this paper. We present assays of dust and radon daughters depositing on the surface of components as well as cleanliness controls necessary to maintain background expectations through detector construction and assembly. Finally, examples from the campaign to highlight fixed contaminant radioassays for the LZ photomultiplier tubes, quality control and quality assurance procedures through fabrication, radon emanation measurements of major sub-systems, and bespoke detector systems to assay scintillator are presented.
Published: 2020

19. Improved Constraints on Sterile Neutrino Mixing from Disappearance Searches in the MINOS, MINOS+, Daya Bay, and Bugey-3 Experiments

Author: Adamson, P, An, FP, Anghel, I, Aurisano, A, Balantekin, AB, Band, HR, Barr, G, Bishai, M, Blake, A, Blyth, S, Cao, GF, Cao, J, Cao, SV, Carroll, TJ, Castromonte, CM, Chang, JF, Chang, Y, Chen, HS, Chen, R, Chen, SM, Chen, Y, Chen, YX, Cheng, J, Cheng, ZK, Cherwinka, JJ, Childress, S, Chu, MC, Chukanov, A, Coelho, JAB, Cummings, JP, Dash, N, De Rijck, S, Deng, FS, Ding, YY, Diwan, MV, Dohnal, T, Dolzhikov, D, Dove, J, Dvořák, M, Dwyer, DA, Evans, JJ, Feldman, GJ, Flanagan, W, Gabrielyan, M, Gallo, JP, Germani, S, Gomes, RA, Gonchar, M, Gong, GH, Gong, H, Gouffon, P, Graf, N, Grzelak, K, Gu, WQ, Guo, JY, Guo, L, Guo, XH, Guo, YH, Guo, Z, Habig, A, Hackenburg, RW, Hahn, SR, Hans, S, Hartnell, J, Hatcher, R, He, M, Heeger, KM, Heng, YK, Higuera, A, Holin, A, Hor, YK, Hsiung, YB, Hu, BZ, Hu, JR, Hu, T, Hu, ZJ, Huang, HX, Huang, J, Huang, XT, Huang, YB, Huber, P, Jaffe, DE, Jen, KL, Ji, XL, Ji, XP, Johnson, RA, Jones, D, Kang, L, Kettell, SH, Koerner, LW, Kohn, S, Kordosky, M, Kramer, M, Kreymer, A, Lang, K, Langford, TJ, Lee, J, Lee, JHC, Lei, RT, and Leitner, R
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Daya Bay Collaboration, MINOS+ Collaboration, hep-ex, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract: Searches for electron antineutrino, muon neutrino, and muon antineutrino disappearance driven by sterile neutrino mixing have been carried out by the Daya Bay and MINOS+ collaborations. This Letter presents the combined results of these searches, along with exclusion results from the Bugey-3 reactor experiment, framed in a minimally extended four-neutrino scenario. Significantly improved constraints on the θ_{μe} mixing angle are derived that constitute the most constraining limits to date over five orders of magnitude in the mass-squared splitting Δm_{41}^{2}, excluding the 90% C.L. sterile-neutrino parameter space allowed by the LSND and MiniBooNE observations at 90% CL_{s} for Δm_{41}^{2}
Published: 2020

20. Projected WIMP sensitivity of the LUX-ZEPLIN dark matter experiment

Author: Akerib, DS, Akerlof, CW, Alsum, SK, Araújo, HM, Arthurs, M, Bai, X, Bailey, AJ, Balajthy, J, Balashov, S, Bauer, D, Belle, J, Beltrame, P, Benson, T, Bernard, EP, Biesiadzinski, TP, Boast, KE, Boxer, B, Brás, P, Buckley, JH, Bugaev, VV, Burdin, S, Busenitz, JK, Carels, C, Carlsmith, DL, Carlson, B, Carmona-Benitez, MC, Chan, C, Cherwinka, JJ, Cole, A, Cottle, A, Craddock, WW, Currie, A, Cutter, JE, Dahl, CE, de Viveiros, L, Dobi, A, Dobson, JEY, Druszkiewicz, E, Edberg, TK, Edwards, WR, Fan, A, Fayer, S, Fiorucci, S, Fruth, T, Gaitskell, RJ, Genovesi, J, Ghag, C, Gilchriese, MGD, van der Grinten, MGD, Hall, CR, Hans, S, Hanzel, K, Haselschwardt, SJ, Hertel, SA, Hillbrand, S, Hjemfelt, C, Hoff, MD, Hor, JY-K, Huang, DQ, Ignarra, CM, Ji, W, Kaboth, AC, Kamdin, K, Keefner, J, Khaitan, D, Khazov, A, Kim, YD, Kocher, CD, Korolkova, EV, Kraus, H, Krebs, HJ, Kreczko, L, Krikler, B, Kudryavtsev, VA, Kyre, S, Lee, J, Lenardo, BG, Leonard, DS, Lesko, KT, Levy, C, Li, J, Liao, J, Liao, F-T, Lin, J, Lindote, A, Linehan, R, Lippincott, WH, Liu, X, Lopes, MI, Paredes, B López, Lorenzon, W, Luitz, S, Lyle, JM, Majewski, P, Manalaysay, A, Mannino, RL, Maupin, C, McKinsey, DN, Meng, Y, and Miller, EH
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, astro-ph.IM, astro-ph.CO, hep-ex, physics.ins-det
Abstract: LUX-ZEPLIN (LZ) is a next-generation dark matter direct detection experiment that will operate 4850 feet underground at the Sanford Underground Research Facility (SURF) in Lead, South Dakota, USA. Using a two-phase xenon detector with an active mass of 7 tonnes, LZ will search primarily for low-energy interactions with weakly interacting massive particles (WIMPs), which are hypothesized to make up the dark matter in our galactic halo. In this paper, the projected WIMP sensitivity of LZ is presented based on the latest background estimates and simulations of the detector. For a 1000 live day run using a 5.6-tonne fiducial mass, LZ is projected to exclude at 90% confidence level spin-independent WIMP-nucleon cross sections above 1.4×10-48 cm2 for a 40 GeV/c2 mass WIMP. Additionally, a 5σ discovery potential is projected, reaching cross sections below the exclusion limits of recent experiments. For spin-dependent WIMP-neutron(-proton) scattering, a sensitivity of 2.3×10-43 cm2 (7.1×10-42 cm2) for a 40 GeV/c2 mass WIMP is expected. With underground installation well underway, LZ is on track for commissioning at SURF in 2020.
Published: 2020

21. The LUX-ZEPLIN (LZ) experiment

Author: Akerib, DS, Akerlof, CW, Akimov, DY, Alquahtani, A, Alsum, SK, Anderson, TJ, Angelides, N, Araújo, HM, Arbuckle, A, Armstrong, JE, Arthurs, M, Auyeung, H, Bai, X, Bailey, AJ, Balajthy, J, Balashov, S, Bang, J, Barry, MJ, Barthel, J, Bauer, D, Bauer, P, Baxter, A, Belle, J, Beltrame, P, Bensinger, J, Benson, T, Bernard, EP, Bernstein, A, Bhatti, A, Biekert, A, Biesiadzinski, TP, Birrittella, B, Boast, KE, Bolozdynya, AI, Boulton, EM, Boxer, B, Bramante, R, Branson, S, Brás, P, Breidenbach, M, Buckley, JH, Bugaev, VV, Bunker, R, Burdin, S, Busenitz, JK, Campbell, JS, Carels, C, Carlsmith, DL, Carlson, B, Carmona-Benitez, MC, Cascella, M, Chan, C, Cherwinka, JJ, Chiller, AA, Chiller, C, Chott, NI, Cole, A, Coleman, J, Colling, D, Conley, RA, Cottle, A, Coughlen, R, Craddock, WW, Curran, D, Currie, A, Cutter, JE, da Cunha, JP, Dahl, CE, Dardin, S, Dasu, S, Davis, J, Davison, TJR, de Viveiros, L, Decheine, N, Dobi, A, Dobson, JEY, Druszkiewicz, E, Dushkin, A, Edberg, TK, Edwards, WR, Edwards, BN, Edwards, J, Elnimr, MM, Emmet, WT, Eriksen, SR, Faham, CH, Fan, A, Fayer, S, Fiorucci, S, Flaecher, H, Fogarty Florang, IM, Ford, P, Francis, VB, Froborg, F, Fruth, T, Gaitskell, RJ, Gantos, NJ, Garcia, D, Geffre, A, and Gehman, VM
Subjects: Dark matter detector, Liquid xenon, Time projection chamber, Underground, physics.ins-det, astro-ph.IM, hep-ex, Nuclear & Particles Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Other Physical Sciences
Abstract: We describe the design and assembly of the LUX-ZEPLIN experiment, a direct detection search for cosmic WIMP dark matter particles. The centerpiece of the experiment is a large liquid xenon time projection chamber sensitive to low energy nuclear recoils. Rejection of backgrounds is enhanced by a Xe skin veto detector and by a liquid scintillator Outer Detector loaded with gadolinium for efficient neutron capture and tagging. LZ is located in the Davis Cavern at the 4850’ level of the Sanford Underground Research Facility in Lead, South Dakota, USA. We describe the major subsystems of the experiment and its key design features and requirements.
Published: 2020

22. A high precision calibration of the nonlinear energy response at Daya Bay

Author: Adey, D, An, FP, Balantekin, AB, Band, HR, Bishai, M, Blyth, S, Cao, D, Cao, GF, Cao, J, Chang, JF, Chang, Y, Chen, HS, Chen, SM, Chen, Y, Chen, YX, Cheng, J, Cheng, ZK, Cherwinka, JJ, Chu, MC, Chukanov, A, Cummings, JP, Dash, N, Deng, FS, Ding, YY, Diwan, MV, Dohnal, T, Dove, J, Dvořák, M, Dwyer, DA, Gonchar, M, Gong, GH, Gong, H, Gu, WQ, Guo, JY, Guo, L, Guo, XH, Guo, YH, Guo, Z, Hackenburg, RW, Hans, S, He, M, Heeger, KM, Heng, YK, Higuera, A, Hor, YK, Hsiung, YB, Hu, BZ, Hu, JR, Hu, T, Hu, ZJ, Huang, HX, Huang, XT, Huang, YB, Huber, P, Jaffe, DE, Jen, KL, Jetter, S, Ji, XL, Ji, XP, Johnson, RA, Jones, D, Kang, L, Kettell, SH, Koerner, LW, Kohn, S, Kramer, M, Langford, TJ, Lebanowski, L, Lee, J, Lee, JHC, Lei, RT, Leitner, R, Leung, JKC, Li, C, Li, F, Li, HL, Li, QJ, Li, S, Li, SC, Li, SJ, Li, WD, Li, XN, Li, XQ, Li, YF, Li, ZB, Liang, H, Lin, CJ, Lin, GL, Lin, S, Lin, SK, Ling, JJ, Link, JM, Littenberg, L, Littlejohn, BR, Liu, JC, Liu, JL, Liu, Y, Liu, YH, Lu, C, and Lu, HQ
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, Affordable and Clean Energy, Neutrino, Liquid scintillator, Energy calibration, Daya Bay, physics.ins-det, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Other Physical Sciences, Nuclear & Particles Physics, Nuclear and plasma physics
Abstract: A high precision calibration of the nonlinearity in the energy response of the Daya Bay Reactor Neutrino Experiment's antineutrino detectors is presented in detail. The energy nonlinearity originates from the particle-dependent light yield of the scintillator and charge-dependent electronics response. The nonlinearity model is constrained by γ calibration points from deployed and naturally occurring radioactive sources, the β spectrum from 12B decays, and a direct measurement of the electronics nonlinearity with a new flash analog-to-digital converter readout system. Less than 0.5% uncertainty in the energy nonlinearity calibration is achieved for positrons of kinetic energies greater than 1 MeV.
Published: 2019

23. Extraction of the U235 and Pu239 Antineutrino Spectra at Daya Bay

Author: Adey, D, An, FP, Balantekin, AB, Band, HR, Bishai, M, Blyth, S, Cao, D, Cao, GF, Cao, J, Chang, JF, Chang, Y, Chen, HS, Chen, SM, Chen, Y, Chen, YX, Cheng, J, Cheng, ZK, Cherwinka, JJ, Chu, MC, Chukanov, A, Cummings, JP, Dash, N, Deng, FS, Ding, YY, Diwan, MV, Dohnal, T, Dove, J, Dvořák, M, Dwyer, DA, Gonchar, M, Gong, GH, Gong, H, Gu, WQ, Guo, JY, Guo, L, Guo, XH, Guo, YH, Guo, Z, Hackenburg, RW, Hans, S, He, M, Heeger, KM, Heng, YK, Higuera, A, Hor, YK, Hsiung, YB, Hu, BZ, Hu, JR, Hu, T, Hu, ZJ, Huang, HX, Huang, XT, Huang, YB, Huber, P, Jaffe, DE, Jen, KL, Ji, XL, Ji, XP, Johnson, RA, Jones, D, Kang, L, Kettell, SH, Koerner, LW, Kohn, S, Kramer, M, Langford, TJ, Lee, J, Lee, JHC, Lei, RT, Leitner, R, Leung, JKC, Li, C, Li, F, Li, HL, Li, QJ, Li, S, Li, SC, Li, SJ, Li, WD, Li, XN, Li, XQ, Li, YF, Li, ZB, Liang, H, Lin, CJ, Lin, GL, Lin, S, Ling, JJ, Link, JM, Littenberg, L, Littlejohn, BR, Liu, JC, Liu, JL, Liu, Y, Liu, YH, Lu, C, Lu, HQ, Lu, JS, Luk, KB, and B., X
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, Daya Bay Collaboration, hep-ex, physics.ins-det, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract: This Letter reports the first extraction of individual antineutrino spectra from ^{235}U and ^{239}Pu fission and an improved measurement of the prompt energy spectrum of reactor antineutrinos at Daya Bay. The analysis uses 3.5×10^{6} inverse beta-decay candidates in four near antineutrino detectors in 1958 days. The individual antineutrino spectra of the two dominant isotopes, ^{235}U and ^{239}Pu, are extracted using the evolution of the prompt spectrum as a function of the isotope fission fractions. In the energy window of 4-6 MeV, a 7% (9%) excess of events is observed for the ^{235}U (^{239}Pu) spectrum compared with the normalized Huber-Mueller model prediction. The significance of discrepancy is 4.0σ for ^{235}U spectral shape compared with the Huber-Mueller model prediction. The shape of the measured inverse beta-decay prompt energy spectrum disagrees with the prediction of the Huber-Mueller model at 5.3σ. In the energy range of 4-6 MeV, a maximal local discrepancy of 6.3σ is observed.
Published: 2019

24. Improved measurement of the reactor antineutrino flux at Daya Bay

Author: Adey, D, An, FP, Balantekin, AB, Band, HR, Bishai, M, Blyth, S, Cao, D, Cao, GF, Cao, J, Chan, YL, Chang, JF, Chang, Y, Chen, HS, Chen, SM, Chen, Y, Chen, YX, Cheng, J, Cheng, ZK, Cherwinka, JJ, Chu, MC, Chukanov, A, Cummings, JP, Deng, FS, Ding, YY, Diwan, MV, Dolgareva, M, Dove, J, Dwyer, DA, Edwards, WR, Gonchar, M, Gong, GH, Gong, H, Gu, WQ, Guo, L, Guo, XH, Guo, YH, Guo, Z, Hackenburg, RW, Hans, S, He, M, Heeger, KM, Heng, YK, Higuera, A, Hsiung, YB, Hu, BZ, Hu, T, Hu, ZJ, Huang, HX, Huang, XT, Huang, YB, Huber, P, Huo, W, Hussain, G, Jaffe, DE, Jen, KL, Ji, XL, Ji, XP, Johnson, RA, Jones, D, Kang, L, Kettell, SH, Koerner, LW, Kohn, S, Kramer, M, Langford, TJ, Lebanowski, L, Lee, J, Lee, JHC, Lei, RT, Leitner, R, Leung, JKC, Li, C, Li, F, Li, HL, Li, QJ, Li, S, Li, SC, Li, SJ, Li, WD, Li, XN, Li, XQ, Li, YF, Li, ZB, Liang, H, Lin, CJ, Lin, GL, Lin, S, Lin, SK, Lin, YC, Ling, JJ, Link, JM, Littenberg, L, Littlejohn, BR, Liu, JC, Liu, JL, Liu, Y, Liu, YH, Loh, CW, Lu, C, and Lu, HQ
Subjects: hep-ex, physics.ins-det, Digestive Diseases
Abstract: This work reports a precise measurement of the reactor antineutrino flux using 2.2 million inverse beta decay (IBD) events collected with the Daya Bay near detectors in 1230 days. The dominant uncertainty on the neutron detection efficiency is reduced by 56% with respect to the previous measurement through a comprehensive neutron calibration and detailed data and simulation analysis. The new average IBD yield is determined to be (5.91±0.09)×10-43 cm2/fission with total uncertainty improved by 29%. The corresponding mean fission fractions from the four main fission isotopes U235, U238, Pu239, and Pu241 are 0.564, 0.076, 0.304, and 0.056, respectively. The ratio of measured to predicted antineutrino yield is found to be 0.952±0.014±0.023 (1.001±0.015±0.027) for the Huber-Mueller (ILL-Vogel) model, where the first and second uncertainty are experimental and theoretical model uncertainty, respectively. This measurement confirms the discrepancy between the world average of reactor antineutrino flux and the Huber-Mueller model.
Published: 2019

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

Author: Adey, D, An, FP, Balantekin, AB, Band, HR, Bishai, M, Blyth, S, Cao, D, Cao, GF, Cao, J, Chang, JF, Chang, Y, Chen, HS, Chen, SM, Chen, Y, Chen, YX, Cheng, J, Cheng, ZK, Cherwinka, JJ, Chu, MC, Chukanov, A, Cummings, JP, Dash, N, Deng, FS, Ding, YY, Diwan, MV, Dohnal, T, Dove, J, Dvořák, M, Dwyer, DA, Gonchar, M, Gong, GH, Gong, H, Gu, WQ, Guo, JY, Guo, L, Guo, XH, Guo, YH, Guo, Z, Hackenburg, RW, Hans, S, He, M, Heeger, KM, Heng, YK, Higuera, A, Hor, YK, Hsiung, YB, Hu, BZ, Hu, JR, Hu, T, Hu, ZJ, Huang, HX, Huang, XT, Huang, YB, Huber, P, Jaffe, DE, Jen, KL, Ji, XL, Ji, XP, Johnson, RA, Jones, D, Kang, L, Kettell, SH, Koerner, LW, Kohn, S, Kramer, M, Langford, TJ, Lee, J, Lee, JHC, Lei, RT, Leitner, R, Leung, JKC, Li, C, Li, F, Li, HL, Li, QJ, Li, S, Li, SC, Li, SJ, Li, WD, Li, XN, Li, XQ, Li, YF, Li, ZB, Liang, H, Lin, CJ, Lin, GL, Lin, S, Ling, JJ, Link, JM, Littenberg, L, Littlejohn, BR, Liu, JC, Liu, JL, Liu, Y, Liu, YH, Lu, C, Lu, HQ, Lu, JS, Luk, KB, and Ma, XB
Subjects: Daya Bay Collaboration, hep-ex, physics.ins-det, General Physics, Mathematical Sciences, Physical Sciences, Engineering
Abstract: This Letter reports the first extraction of individual antineutrino spectra from ^{235}U and ^{239}Pu fission and an improved measurement of the prompt energy spectrum of reactor antineutrinos at Daya Bay. The analysis uses 3.5×10^{6} inverse beta-decay candidates in four near antineutrino detectors in 1958 days. The individual antineutrino spectra of the two dominant isotopes, ^{235}U and ^{239}Pu, are extracted using the evolution of the prompt spectrum as a function of the isotope fission fractions. In the energy window of 4-6 MeV, a 7% (9%) excess of events is observed for the ^{235}U (^{239}Pu) spectrum compared with the normalized Huber-Mueller model prediction. The significance of discrepancy is 4.0σ for ^{235}U spectral shape compared with the Huber-Mueller model prediction. The shape of the measured inverse beta-decay prompt energy spectrum disagrees with the prediction of the Huber-Mueller model at 5.3σ. In the energy range of 4-6 MeV, a maximal local discrepancy of 6.3σ is observed.
Published: 2019

26. Response to Comment on Daya Bay's definition and use of Delta(m^2_ee)

Author: Collaboration, The Day Bay, Adey, D, An, FP, Balantekin, AB, Band, HR, Bishai, M, Blyth, S, Cao, D, Cao, GF, Cao, J, Chang, JF, Chang, Y, Chen, HS, Chen, SM, Chen, Y, Chen, YX, Cheng, J, Cheng, ZK, Cherwinka, JJ, Chu, MC, Chukanov, A, Cummings, JP, Dash, N, Deng, FS, Ding, YY, Diwan, MV, Dohnal, T, Dove, J, Dvorak, M, Dwyer, DA, Gonchar, M, Gong, GH, Gong, H, Gu, WQ, Guo, JY, Guo, L, Guo, XH, Guo, YH, Guo, Z, Hackenburg, RW, Hans, S, He, M, Heeger, KM, Heng, YK, Higuera, A, Hor, YK, Hsiung, YB, Hu, BZ, Hu, JR, Hu, T, Hu, ZJ, Huang, HX, Huang, XT, Huang, YB, Huber, P, Jaffe, DE, Jen, KL, Ji, XL, Ji, XP, Johnson, RA, Jones, D, Kang, L, Kettell, SH, Koerner, LW, Kohn, S, Kramer, M, Langford, TJ, Lee, J, Lee, JHC, Lei, RT, Leitner, R, Leung, JKC, Li, C, Li, F, Li, HL, Li, QJ, Li, S, Li, SC, Li, SJ, Li, WD, Li, XN, Li, XQ, Li, YF, Li, ZB, Liang, H, Lin, CJ, Lin, GL, Lin, S, Lin, SK, Ling, JJ, Link, JM, Littenberg, L, Littlejohn, BR, Liu, JC, Liu, JL, Liu, Y, Liu, YH, Lu, C, Lu, HQ, and Lu, JS
Subjects: hep-ex
Abstract: The Daya Bay Collaboration responds to comments posted by S. Parke and R.Zukanovich Funchal regarding our use of Delta(m^2_ee).
Published: 2019

27. Measurement of the Electron Antineutrino Oscillation with 1958 Days of Operation at Daya Bay

Author: Adey, D, An, FP, Balantekin, AB, Band, HR, Bishai, M, Blyth, S, Cao, D, Cao, GF, Cao, J, Chan, YL, Chang, JF, Chang, Y, Chen, HS, Chen, SM, Chen, Y, Chen, YX, Cheng, J, Cheng, ZK, Cherwinka, JJ, Chu, MC, Chukanov, A, Cummings, JP, Deng, FS, Ding, YY, Diwan, MV, Dolgareva, M, Dwyer, DA, Edwards, WR, Gonchar, M, Gong, GH, Gong, H, Gu, WQ, Guo, L, Guo, XH, Guo, YH, Guo, Z, Hackenburg, RW, Hans, S, He, M, Heeger, KM, Heng, YK, Higuera, A, Hsiung, YB, Hu, BZ, Hu, JR, Hu, T, Hu, ZJ, Huang, HX, Huang, XT, Huang, YB, Huber, P, Huo, W, Hussain, G, Jaffe, DE, Jen, KL, Ji, XL, Ji, XP, Johnson, RA, Jones, D, Kang, L, Kettell, SH, Koerner, LW, Kohn, S, Kramer, M, Langford, TJ, Lebanowski, L, Lee, J, Lee, JHC, Lei, RT, Leitner, R, Leung, JKC, Li, C, Li, F, Li, HL, Li, QJ, Li, S, Li, SC, Li, SJ, Li, WD, Li, XN, Li, XQ, Li, YF, Li, ZB, Liang, H, Lin, CJ, Lin, GL, Lin, S, Lin, SK, Lin, Y-C, Ling, JJ, Link, JM, Littenberg, L, Littlejohn, BR, Liu, JC, Liu, JL, Liu, Y, Liu, YH, Loh, CW, Lu, C, and Lu, HQ
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, Daya Bay Collaboration, hep-ex, physics.ins-det, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract: We report a measurement of electron antineutrino oscillation from the Daya Bay Reactor Neutrino Experiment with nearly 4 million reactor ν[over ¯]_{e} inverse β decay candidates observed over 1958 days of data collection. The installation of a flash analog-to-digital converter readout system and a special calibration campaign using different source enclosures reduce uncertainties in the absolute energy calibration to less than 0.5% for visible energies larger than 2 MeV. The uncertainty in the cosmogenic ^{9}Li and ^{8}He background is reduced from 45% to 30% in the near detectors. A detailed investigation of the spent nuclear fuel history improves its uncertainty from 100% to 30%. Analysis of the relative ν[over ¯]_{e} rates and energy spectra among detectors yields sin^{2}2θ_{13}=0.0856±0.0029 and Δm_{32}^{2}=(2.471_{-0.070}^{+0.068})×10^{-3} eV^{2} assuming the normal hierarchy, and Δm_{32}^{2}=-(2.575_{-0.070}^{+0.068})×10^{-3} eV^{2} assuming the inverted hierarchy.
Published: 2018

28. Search for a time-varying electron antineutrino signal at Daya Bay

Author: Adey, D, An, FP, Balantekin, AB, Band, HR, Bishai, M, Blyth, S, Cao, D, Cao, GF, Cao, J, Chang, JF, Chang, Y, Chen, HS, Chen, SM, Chen, Y, Chen, YX, Cheng, J, Cheng, ZK, Cherwinka, JJ, Chu, MC, Chukanov, A, Cummings, JP, Dash, N, Deng, FS, Ding, YY, Diwan, MV, Dohnal, T, Dove, J, Dvořák, M, Dwyer, DA, Gonchar, M, Gong, GH, Gong, H, Gu, WQ, Guo, JY, Guo, L, Guo, XH, Guo, YH, Guo, Z, Hackenburg, RW, Hans, S, He, M, Heeger, KM, Heng, YK, Higuera, A, Hsiung, YB, Hu, BZ, Hu, JR, Hu, T, Hu, ZJ, Huang, HX, Huang, XT, Huang, YB, Huber, P, Jaffe, DE, Jen, KL, Ji, XL, Ji, XP, Johnson, RA, Jones, D, Kang, L, Kettell, SH, Koerner, LW, Kohn, S, Kramer, M, Langford, TJ, Lau, K, Lebanowski, L, Lee, J, Lee, JHC, Lei, RT, Leitner, R, Leung, JKC, Li, C, Li, F, Li, HL, Li, QJ, Li, S, Li, SC, Li, SJ, Li, WD, Li, XN, Li, XQ, Li, YF, Li, ZB, Liang, H, Lin, CJ, Lin, GL, Lin, S, Lin, Y-C, Ling, JJ, Link, JM, Littenberg, L, Littlejohn, BR, Liu, JC, Liu, JL, Liu, Y, Liu, YH, Lu, C, Lu, HQ, and Lu, JS
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, hep-ex, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Mathematical physics, Astronomical sciences, Particle and high energy physics
Abstract: A search for a time-varying νe signal was performed with 621 days of data acquired by the Daya Bay Reactor Neutrino Experiment over 704 calendar days. The time spectrum of the measured νe flux normalized to its prediction was analyzed with a Lomb-Scargle periodogram, which yielded no significant signal for periods ranging from 2 hours to nearly 2 years. The normalized time spectrum was also fit for a sidereal modulation under the Standard Model Extension (SME) framework to search for Lorentz and CPT violation (LV-CPTV). Limits were obtained for all six flavor pairs ēμ,ēτ, μτ, ēē,μμ and ττ by fitting them one at a time, constituting the first experimental constraints on the latter three. Daya Bay's high statistics and unique layout of multiple directions from three pairs of reactors to three experimental halls allowed the simultaneous constraint of individual SME LV-CPTV coefficients without assuming others contribute negligibly, a first for a neutrino experiment.
Published: 2018

29. Cosmogenic neutron production at Daya Bay

Author: An, FP, Balantekin, AB, Band, HR, Bishai, M, Blyth, S, Cao, D, Cao, GF, Cao, J, Chan, YL, Chang, JF, Chang, Y, Chen, HS, Chen, SM, Chen, Y, Chen, YX, Cheng, J, Cheng, ZK, Cherwinka, JJ, Chu, MC, Chukanov, A, Cummings, JP, Ding, YY, Diwan, MV, Dolgareva, M, Dove, J, Dwyer, DA, Edwards, WR, Gill, R, Gonchar, M, Gong, GH, Gong, H, Grassi, M, Gu, WQ, Guo, L, Guo, XH, Guo, YH, Guo, Z, Hackenburg, RW, Hans, S, He, M, Heeger, KM, Heng, YK, Higuera, A, Hsiung, YB, Hu, BZ, Hu, T, Huang, HX, Huang, XT, Huang, YB, Huber, P, Huo, W, Hussain, G, Jaffe, DE, Jen, KL, Ji, XL, Ji, XP, Jiao, JB, Johnson, RA, Jones, D, Kang, L, Kettell, SH, Khan, A, Koerner, LW, Kohn, S, Kramer, M, Kwok, MW, Langford, TJ, Lau, K, Lebanowski, L, Lee, J, Lee, JHC, Lei, RT, Leitner, R, Leung, JKC, Li, C, Li, DJ, Li, F, Li, GS, Li, QJ, Li, S, Li, SC, Li, WD, Li, XN, Li, XQ, Li, YF, Li, ZB, Liang, H, Lin, CJ, Lin, GL, Lin, S, Lin, SK, Lin, Y-C, Ling, JJ, Link, JM, Littenberg, L, Littlejohn, BR, Liu, JC, Liu, JL, Loh, CW, and Lu, C
Subjects: hep-ex, physics.ins-det
Abstract: Neutrons produced by cosmic ray muons are an important background forunderground experiments studying neutrino oscillations, neutrinoless doublebeta decay, dark matter, and other rare-event signals. A measurement of theneutron yield in the three different experimental halls of the Daya Bay ReactorNeutrino Experiment at varying depth is reported. The neutron yield in DayaBay's liquid scintillator is measured to be $Y_n=(10.26\pm 0.86)\times10^{-5}$, $(10.22\pm 0.87)\times 10^{-5}$, and $(17.03\pm 1.22)\times10^{-5}~\mu^{-1}~$g$^{-1}~$cm$^2$ at depths of 250, 265, and 860meters-water-equivalent. These results are compared to other measurements andthe simulated neutron yield in Fluka and Geant4. A global fit including theDaya Bay measurements yields a power law coefficient of $0.77 \pm 0.03$ for thedependence of the neutron yield on muon energy.
Published: 2018

30. Seasonal variation of the underground cosmic muon flux observed at Daya Bay

Author: An, FP, Balantekin, AB, Band, HR, Bishai, M, Blyth, S, Cao, D, Cao, GF, Cao, J, Chan, YL, Chang, JF, Chang, Y, Chen, HS, Chen, QY, Chen, SM, Chen, YX, Chen, Y, Cheng, J, Cheng, ZK, Cherwinka, JJ, Chu, MC, Chukanov, A, Cummings, JP, Ding, YY, Diwan, MV, Dolgareva, M, Dove, J, Dwyer, DA, Edwards, WR, Gill, R, Gonchar, M, Gong, GH, Gong, H, Grassi, M, Gu, WQ, Guo, L, Guo, XH, Guo, YH, Guo, Z, Hackenburg, RW, Hans, S, He, M, Heeger, KM, Heng, YK, Higuera, A, Hsiung, YB, Hu, BZ, Hu, T, Huang, EC, Huang, HX, Huang, XT, Huber, P, Huo, W, Hussain, G, Jaffe, DE, Jen, KL, Jetter, S, Ji, XP, Ji, XL, Jiao, JB, Johnson, RA, Jones, D, Kang, L, Kettell, SH, Khan, A, Kohn, S, Kramer, M, Kwan, KK, Kwok, MW, Kwok, T, Langford, TJ, Lau, K, Lebanowski, L, Lee, J, Lee, JHC, Lei, RT, Leitner, R, Li, C, Li, DJ, Li, F, Li, GS, Li, QJ, Li, S, Li, SC, Li, WD, Li, XN, Li, XQ, Li, YF, Li, ZB, Liang, H, Lin, CJ, Lin, GL, Lin, S, Lin, SK, Lin, Y-C, Ling, JJ, Link, JM, Littenberg, L, Littlejohn, BR, Liu, JL, and Liu, JC
Subjects: Particle and High Energy Physics, Physical Sciences, cosmic ray experiments, neutrino detectors, neutrino experiments, physics.ins-det, hep-ex, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Astronomical sciences, Particle and high energy physics
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 α, describing how a variation in the muon rate relates to a variation in the effective atmospheric temperature, is found to be αEH1 = 0.362±0.031, αEH2 = 0.433±0.038 and αEH3 = 0.641±0.057 for each experimental hall.
Published: 2018

31. Identification of radiopure titanium for the LZ dark matter experiment and future rare event searches

Author: Akerib, DS, Akerlof, CW, Akimov, DY, Alsum, SK, Araújo, HM, Arnquist, IJ, Arthurs, M, Bai, X, Bailey, AJ, Balajthy, J, Balashov, S, Barry, MJ, Belle, J, Beltrame, P, Benson, T, Bernard, EP, Bernstein, A, Biesiadzinski, TP, Boast, KE, Bolozdynya, A, Boxer, B, Bramante, R, Brás, P, Buckley, JH, Bugaev, VV, Bunker, R, Burdin, S, Busenitz, JK, Carels, C, Carlsmith, DL, Carlson, B, Carmona-Benitez, MC, Chan, C, Cherwinka, JJ, Chiller, AA, Chiller, C, Cottle, A, Coughlen, R, Craddock, WW, Currie, A, Dahl, CE, Davison, TJR, Dobi, A, Dobson, JEY, Druszkiewicz, E, Edberg, TK, Edwards, WR, Emmet, WT, Faham, CH, Fiorucci, S, Fruth, T, Gaitskell, RJ, Gantos, NJ, Gehman, VM, Gerhard, RM, Ghag, C, Gilchriese, MGD, Gomber, B, Hall, CR, Hans, S, Hanzel, K, Haselschwardt, SJ, Hertel, SA, Hillbrand, S, Hjemfelt, C, Hoff, MD, Holbrook, B, Holtom, E, Hoppe, EW, Hor, JYK, Horn, M, Huang, DQ, Hurteau, TW, Ignarra, CM, Jacobsen, RG, Ji, W, Kaboth, A, Kamdin, K, Kazkaz, K, Khaitan, D, Khazov, A, Khromov, AV, Konovalov, AM, Korolkova, EV, Koyuncu, M, Kraus, H, Krebs, HJ, Kudryavtsev, VA, Kumpan, AV, Kyre, S, Lee, C, Lee, HS, Lee, J, Leonard, DS, Leonard, R, Lesko, KT, Levy, C, Liao, FT, Lin, J, and Lindote, A
Subjects: physics.ins-det, hep-ex, Nuclear & Particles Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract: The LUX-ZEPLIN (LZ) experiment will search for dark matter particle interactions with a detector containing a total of 10 tonnes of liquid xenon within a double-vessel cryostat. The large mass and proximity of the cryostat to the active detector volume demand the use of material with extremely low intrinsic radioactivity. We report on the radioassay campaign conducted to identify suitable metals, the determination of factors limiting radiopure production, and the selection of titanium for construction of the LZ cryostat and other detector components. This titanium has been measured with activities of 238Ue < 1.6 mBq/kg, 238Ul < 0.09 mBq/kg, 232The=0.28±0.03 mBq/kg, 232Thl=0.25±0.02 mBq/kg, 40K < 0.54 mBq/kg, and 60Co < 0.02 mBq/kg (68% CL). Such low intrinsic activities, which are some of the lowest ever reported for titanium, enable its use for future dark matter and other rare event searches. Monte Carlo simulations have been performed to assess the expected background contribution from the LZ cryostat with this radioactivity. In 1,000 days of WIMP search exposure of a 5.6-tonne fiducial mass, the cryostat will contribute only a mean background of 0.160 ± 0.001(stat) ± 0.030(sys) counts.
Published: 2017

32. Study of the wave packet treatment of neutrino oscillation at Daya Bay

Author: An, FP, Balantekin, AB, Band, HR, Bishai, M, Blyth, S, Cao, D, Cao, GF, Cao, J, Cen, WR, Chan, YL, Chang, JF, Chang, LC, Chang, Y, Chen, HS, Chen, QY, Chen, SM, Chen, YX, Chen, Y, Cheng, J-H, Cheng, J, Cheng, YP, Cheng, ZK, Cherwinka, JJ, Chu, MC, Chukanov, A, Cummings, JP, de Arcos, J, Deng, ZY, Ding, XF, Ding, YY, Diwan, MV, Dolgareva, M, Dove, J, Dwyer, DA, Edwards, WR, Gill, R, Gonchar, M, Gong, GH, Gong, H, Grassi, M, Gu, WQ, Guan, MY, Guo, L, Guo, XH, Guo, Z, Hackenburg, RW, Han, R, Hans, S, He, M, Heeger, KM, Heng, YK, Higuera, A, Hor, YK, Hsiung, YB, Hu, BZ, Hu, T, Hu, W, Huang, EC, Huang, HX, Huang, XT, Huber, P, Huo, W, Hussain, G, Jaffe, DE, Jen, KL, Jetter, S, Ji, XP, Ji, XL, Jiao, JB, Johnson, RA, Jones, D, Joshi, J, Kettell, SH, Kohn, S, Kramer, M, Kwan, KK, Kwok, MW, Kwok, T, Langford, TJ, Lau, K, Lebanowski, L, Lee, J, Lee, JHC, Lei, RT, Leitner, R, Li, C, Li, DJ, Li, F, Li, GS, Li, QJ, Li, S, Li, SC, Li, WD, Li, XN, Li, YF, Li, ZB, Liang, H, Lin, CJ, Lin, GL, and Lin, S
Subjects: hep-ex, hep-ph, Nuclear & Particles Physics, Quantum Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract: The disappearance of reactor $\bar{\nu}_e$ observed by the Daya Bayexperiment is examined in the framework of a model in which the neutrino isdescribed by a wave packet with a relative intrinsic momentum dispersion$\sigma_\text{rel}$. Three pairs of nuclear reactors and eight antineutrinodetectors, each with good energy resolution, distributed among threeexperimental halls, supply a high-statistics sample of $\bar{\nu}_e$ acquiredat nine different baselines. This provides a unique platform to test theeffects which arise from the wave packet treatment of neutrino oscillation. Themodified survival probability formula was used to fit Daya Bay data, providingthe first experimental limits: $2.38 \cdot 10^{-17} < \sigma_{\rm rel} < 0.23$.Treating the dimensions of the reactor cores and detectors as constraints, thelimits are improved: $10^{-14} \lesssim \sigma_{\rm rel} < 0.23$, and an upperlimit of $\sigma_{\rm rel}
Published: 2017

33. Evolution of the Reactor Antineutrino Flux and Spectrum at Daya Bay

Author: An, FP, Balantekin, AB, Band, HR, Bishai, M, Blyth, S, Cao, D, Cao, GF, Cao, J, Chan, YL, Chang, JF, Chang, Y, Chen, HS, Chen, QY, Chen, SM, Chen, YX, Chen, Y, Cheng, J, Cheng, ZK, Cherwinka, JJ, Chu, MC, Chukanov, A, Cummings, JP, Ding, YY, Diwan, MV, Dolgareva, M, Dove, J, Dwyer, DA, Edwards, WR, Gill, R, Gonchar, M, Gong, GH, Gong, H, Grassi, M, Gu, WQ, Guo, L, Guo, XH, Guo, YH, Guo, Z, Hackenburg, RW, Hans, S, He, M, Heeger, KM, Heng, YK, Higuera, A, Hsiung, YB, Hu, BZ, Hu, T, Huang, EC, Huang, HX, Huang, XT, Huang, YB, Huber, P, Huo, W, Hussain, G, Jaffe, DE, Jen, KL, Ji, XP, Ji, XL, Jiao, JB, Johnson, RA, Jones, D, Kang, L, Kettell, SH, Khan, A, Kohn, S, Kramer, M, Kwan, KK, Kwok, MW, Langford, TJ, Lau, K, Lebanowski, L, Lee, J, Lee, JHC, Lei, RT, Leitner, R, Leung, JKC, Li, C, Li, DJ, Li, F, Li, GS, Li, QJ, Li, S, Li, SC, Li, WD, Li, XN, Li, XQ, Li, YF, Li, ZB, Liang, H, Lin, CJ, Lin, GL, Lin, S, Lin, SK, Lin, Y-C, Ling, JJ, Link, JM, Littenberg, L, Littlejohn, BR, Liu, JL, and Liu, JC
Subjects: Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, Daya Bay Collaboration, hep-ex, nucl-ex, physics.ins-det, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
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_{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 σ[over ¯]_{f} of (5.90±0.13)×10^{-43} cm^{2}/fission and a fuel-dependent variation in the IBD yield, dσ_{f}/dF_{239}, of (-1.86±0.18)×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 is 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 3.1σ. This discrepancy indicates that an overall deficit in the 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±0.17) and (4.27±0.26)×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 yields suggests that this isotope may be the primary contributor to the reactor antineutrino anomaly.
Published: 2017

34. Measurement of electron antineutrino oscillation based on 1230 days of operation of the Daya Bay experiment

Author: An, FP, Balantekin, AB, Band, HR, Bishai, M, Blyth, S, Cao, D, Cao, GF, Cao, J, Cen, WR, Chan, YL, Chang, JF, Chang, LC, Chang, Y, Chen, HS, Chen, QY, Chen, SM, Chen, YX, Chen, Y, Cheng, J-H, Cheng, J, Cheng, YP, Cheng, ZK, Cherwinka, JJ, Chu, MC, Chukanov, A, Cummings, JP, de Arcos, J, Deng, ZY, Ding, XF, Ding, YY, Diwan, MV, Dolgareva, M, Dove, J, Dwyer, DA, Edwards, WR, Gill, R, Gonchar, M, Gong, GH, Gong, H, Grassi, M, Gu, WQ, Guan, MY, Guo, L, Guo, XH, Guo, YH, Guo, Z, Hackenburg, RW, Han, R, Hans, S, He, M, Heeger, KM, Heng, YK, Higuera, A, Hor, YK, Hsiung, YB, Hu, BZ, Hu, T, Hu, W, Huang, EC, Huang, HX, Huang, XT, Huber, P, Huo, W, Hussain, G, Jaffe, DE, Jaffke, P, Jen, KL, Jetter, S, Ji, XP, Ji, XL, Jiao, JB, Johnson, RA, Jones, D, Joshi, J, Kang, L, Kettell, SH, Kohn, S, Kramer, M, Kwan, KK, Kwok, MW, Kwok, T, Langford, TJ, Lau, K, Lebanowski, L, Lee, J, Lee, JHC, Lei, RT, Leitner, R, Leung, JKC, Li, C, Li, DJ, Li, F, Li, GS, Li, QJ, Li, S, Li, SC, Li, WD, Li, XN, Li, YF, and Li, ZB
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Affordable and Clean Energy, hep-ex, nucl-ex, physics.ins-det
Abstract: A measurement of electron antineutrino oscillation by the Daya Bay Reactor Neutrino Experiment is described in detail. Six 2.9-GWth nuclear power reactors of the Daya Bay and Ling Ao nuclear power facilities served as intense sources of νe's. Comparison of the νe rate and energy spectrum measured by antineutrino detectors far from the nuclear reactors (∼1500-1950 m) relative to detectors near the reactors (∼350-600 m) allowed a precise measurement of νe disappearance. More than 2.5 million νe inverse beta-decay interactions were observed, based on the combination of 217 days of operation of six antineutrino detectors (December, 2011-July, 2012) with a subsequent 1013 days using the complete configuration of eight detectors (October, 2012-July, 2015). The νe rate observed at the far detectors relative to the near detectors showed a significant deficit, R=0.949±0.002(stat)±0.002(syst). The energy dependence of νe disappearance showed the distinct variation predicted by neutrino oscillation. Analysis using an approximation for the three-flavor oscillation probability yielded the flavor-mixing angle sin22θ13=0.0841±0.0027(stat)±0.0019(syst) and the effective neutrino mass-squared difference of |Δmee2|=(2.50±0.06(stat)±0.06(syst))×10-3 eV2. Analysis using the exact three-flavor probability found Δm322=(2.45±0.06(stat)±0.06(syst))×10-3 eV2 assuming the normal neutrino mass hierarchy and Δm322=(-2.56±0.06(stat)±0.06(syst))×10-3 eV2 for the inverted hierarchy.
Published: 2017

35. Improved measurement of the reactor antineutrino flux and spectrum at Daya Bay

Author: An, FP, Balantekin, AB, Band, HR, Bishai, M, Blyth, S, Cao, D, Cao, GF, Cao, J, Cen, WR, Chan, YL, Chang, JF, Chang, LC, Chang, Y, Chen, HS, Chen, QY, Chen, SM, Chen, YX, Chen, Y, Cheng, J-H, Cheng, J, Cheng, YP, Cheng, ZK, Cherwinka, JJ, Chu, MC, Chukanov, A, Cummings, JP, de Arcos, J, Deng, ZY, Ding, XF, Ding, YY, Diwan, MV, Dolgareva, M, Dove, J, Dwyer, DA, Edwards, WR, Gill, R, Gonchar, M, Gong, GH, Gong, H, Grassi, M, Gu, WQ, Guan, MY, Guo, L, Guo, RP, Guo, XH, Guo, Z, Hackenburg, RW, Han, R, Hans, S, He, M, Heeger, KM, Heng, YK, Higuera, A, Hor, YK, Hsiung, YB, Hu, BZ, Hu, T, Hu, W, Huang, EC, Huang, HX, Huang, XT, Huber, P, Huo, W, Hussain, G, Jaffe, DE, Jaffke, P, Jen, KL, Jetter, S, Ji, XP, Ji, XL, Jiao, JB, Johnson, RA, Jones, D, Joshi, J, Kang, L, Kettell, SH, Kohn, S, Kramer, M, Kwan, KK, Kwok, MW, Kwok, T, Langford, TJ, Lau, K, Lebanowski, L, Lee, J, Lee, JHC, Lei, RT, Leitner, R, Li, C, Li, DJ, Li, F, Li, GS, Li, QJ, Li, S, Li, SC, Li, WD, Li, XN, Li, YF, Li, ZB, and Liang, H
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, antineutrino flux, energy spectrum, reactor, Daya Bay, hep-ex, nucl-ex, physics.ins-det, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Atomic, molecular and optical physics, Particle and high energy physics
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 GWth 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±0.020 (0.992±0.021) for the Huber+Mueller (ILL+Vogel) model. A 2.9σ 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 4.4σ. A reactor antineutrino spectrum weighted by the IBD cross section is extracted for model-independent predictions.
Published: 2017

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

Author: An, FP, Balantekin, AB, Band, HR, Bishai, M, Blyth, S, Cao, D, Cao, GF, Cao, J, Cen, WR, Chan, YL, Chang, JF, Chang, LC, Chang, Y, Chen, HS, Chen, QY, Chen, SM, Chen, YX, Chen, Y, Cheng, J-H, Cheng, J, Cheng, YP, Cheng, ZK, Cherwinka, JJ, Chu, MC, Chukanov, A, Cummings, JP, de Arcos, J, Deng, ZY, Ding, XF, Ding, YY, Diwan, MV, Dolgareva, M, Dove, J, Dwyer, DA, Edwards, WR, Gill, R, Gonchar, M, Gong, GH, Gong, H, Grassi, M, Gu, WQ, Guan, MY, Guo, L, Guo, RP, Guo, XH, Guo, Z, Hackenburg, RW, Han, R, Hans, S, He, M, Heeger, KM, Heng, YK, Higuera, A, Hor, YK, Hsiung, YB, Hu, BZ, Hu, T, Hu, W, Huang, EC, Huang, HX, Huang, XT, Huber, P, Huo, W, Hussain, G, Jaffe, DE, Jaffke, P, Jen, KL, Jetter, S, Ji, XP, Ji, XL, Jiao, JB, Johnson, RA, Joshi, J, Kang, L, Kettell, SH, Kohn, S, Kramer, M, Kwan, KK, Kwok, MW, Kwok, T, Langford, TJ, Lau, K, Lebanowski, L, Lee, J, Lee, JHC, Lei, RT, Leitner, R, Leung, JKC, Li, C, Li, DJ, Li, F, Li, GS, Li, QJ, Li, S, Li, SC, Li, WD, Li, XN, Li, YF, Li, ZB, and Liang, H
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Affordable and Clean Energy, Daya Bay Collaboration, hep-ex, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
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 2×10^{-4}≲|Δm_{41}^{2}|≲0.3 eV^{2} mass range. The resulting limits on sin^{2}2θ_{14} are improved by approx imately a factor of 2 over previous results and constitute the most stringent constraints to date in the |Δm_{41}^{2}|≲0.2 eV^{2} region.
Published: 2016

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

Author: Adamson, P, An, FP, Anghel, I, Aurisano, A, Balantekin, AB, Band, HR, Barr, G, Bishai, M, Blake, A, Blyth, S, Bock, GJ, Bogert, D, Cao, D, Cao, GF, Cao, J, Cao, SV, Carroll, TJ, Castromonte, CM, Cen, WR, Chan, YL, Chang, JF, Chang, LC, Chang, Y, Chen, HS, Chen, QY, Chen, R, Chen, SM, Chen, Y, Chen, YX, Cheng, J, Cheng, J-H, Cheng, YP, Cheng, ZK, Cherwinka, JJ, Childress, S, Chu, MC, Chukanov, A, Coelho, JAB, Corwin, L, Cronin-Hennessy, D, Cummings, JP, de Arcos, J, De Rijck, S, Deng, ZY, Devan, AV, Devenish, NE, Ding, XF, Ding, YY, Diwan, MV, Dolgareva, M, Dove, J, Dwyer, DA, Edwards, WR, Escobar, CO, Evans, JJ, Falk, E, Feldman, GJ, Flanagan, W, Frohne, MV, Gabrielyan, M, Gallagher, HR, Germani, S, Gill, R, Gomes, RA, Gonchar, M, Gong, GH, Gong, H, Goodman, MC, Gouffon, P, Graf, N, Gran, R, Grassi, M, Grzelak, K, Gu, WQ, Guan, MY, Guo, L, Guo, RP, Guo, XH, Guo, Z, Habig, A, Hackenburg, RW, Hahn, SR, Han, R, Hans, S, Hartnell, J, Hatcher, R, He, M, Heeger, KM, Heng, YK, Higuera, A, Holin, A, Hor, YK, Hsiung, YB, Hu, BZ, Hu, T, Hu, W, Huang, EC, Huang, HX, Huang, J, and Huang, XT
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Daya Bay Collaboration, MINOS Collaboration, hep-ex, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
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 Liquid Scintillator Neutrino Detector (LSND) and MiniBooNE experiments in a minimally extended four-neutrino flavor framework. Stringent limits on sin^{2}2θ_{μe} are set over 6 orders of magnitude in the sterile mass-squared splitting Δm_{41}^{2}. The sterile-neutrino mixing phase space allowed by the LSND and MiniBooNE experiments is excluded for Δm_{41}^{2}
Published: 2016

38. New measurement of θ13 via neutron capture on hydrogen at Daya Bay

Author: An, FP, Balantekin, AB, Band, HR, Bishai, M, Blyth, S, Cao, D, Cao, GF, Cao, J, Cen, WR, Chan, YL, Chang, JF, Chang, LC, Chang, Y, Chen, HS, Chen, QY, Chen, SM, Chen, YX, Chen, Y, Cheng, JH, Cheng, J, Cheng, YP, Cheng, ZK, Cherwinka, JJ, Chu, MC, Chukanov, A, Cummings, JP, De Arcos, J, Deng, ZY, Ding, XF, Ding, YY, Diwan, MV, Dolgareva, M, Dove, J, Dwyer, DA, Edwards, WR, Gill, R, Gonchar, M, Gong, GH, Gong, H, Grassi, M, Gu, WQ, Guan, MY, Guo, L, Guo, RP, Guo, XH, Guo, Z, Hackenburg, RW, Han, R, Hans, S, He, M, Heeger, KM, Heng, YK, Higuera, A, Hor, YK, Hsiung, YB, Hu, BZ, Hu, T, Hu, W, Huang, EC, Huang, HX, Huang, XT, Huber, P, Huo, W, Hussain, G, Jaffe, DE, Jaffke, P, Jen, KL, Jetter, S, Ji, XP, Ji, XL, Jiao, JB, Johnson, RA, Joshi, J, Kang, L, Kettell, SH, Kohn, S, Kramer, M, Kwan, KK, Kwok, MW, Kwok, T, Langford, TJ, Lau, K, Lebanowski, L, Lee, J, Lee, JHC, Lei, RT, Leitner, R, Leung, JKC, Li, C, Li, DJ, Li, F, Li, GS, Li, QJ, Li, S, Li, SC, Li, WD, Li, XN, Li, YF, and Li, ZB
Subjects: hep-ex, physics.ins-det
Abstract: This article reports an improved independent measurement of neutrino mixing angle θ13 at the Daya Bay Reactor Neutrino Experiment. Electron antineutrinos were identified by inverse β-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 Li9 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 sin22θ13=0.071±0.011 in the three-neutrino-oscillation framework. The combination of this result with the gadolinium-capture result is also reported.
Published: 2016

39. The detector system of the Daya Bay reactor neutrino experiment

Author: An, FP, Bai, JZ, Balantekin, AB, Band, HR, Beavis, D, Beriguete, W, Bishai, M, Blyth, S, Brown, RL, Butorov, I, Cao, D, Cao, GF, Cao, J, Carr, R, Cen, WR, Chan, WT, Chan, YL, Chang, JF, Chang, LC, Chang, Y, Chasman, C, Chen, HY, Chen, HS, Chen, MJ, Chen, QY, Chen, SJ, Chen, SM, Chen, XC, Chen, XH, Chen, XS, Chen, YX, Chen, Y, Cheng, JH, Cheng, J, Cheng, YP, Cherwinka, JJ, Chidzik, S, Chow, K, Chu, MC, Cummings, JP, de Arcos, J, Deng, ZY, Ding, XF, Ding, YY, Diwan, MV, Dong, L, Dove, J, Draeger, E, Du, XF, Dwyer, DA, Edwards, WR, Ely, SR, Fang, SD, Fu, JY, Fu, ZW, Ge, LQ, Ghazikhanian, V, Gill, R, Goett, J, Gonchar, M, Gong, GH, Gong, H, Gornushkin, YA, Grassi, M, Greenler, LS, Gu, WQ, Guan, MY, Guo, RP, Guo, XH, Hackenburg, RW, Hahn, RL, Han, R, Hans, S, He, M, He, Q, He, WS, Heeger, KM, Heng, YK, Higuera, A, Hinrichs, P, Ho, TH, Hoff, M, Hor, YK, Hsiung, YB, Hu, BZ, Hu, LM, Hu, LJ, Hu, T, Hu, W, Huang, EC, Huang, HZ, Huang, HX, Huang, PW, Huang, X, Huang, XT, Huber, P, Hussain, G, Isvan, Z, Jaffe, DE, and Jaffke, P
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, Neutrino oscillation, Neutrino mixing, Reactor, Daya Bay, physics.ins-det, hep-ex, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Other Physical Sciences, Nuclear & Particles Physics, Nuclear and plasma physics
Abstract: The Daya Bay experiment was the first to report simultaneous measurements of reactor antineutrinos at multiple baselines leading to the discovery of ν¯e oscillations over km-baselines. Subsequent data has provided the world's most precise measurement of sin22θ13 and the effective mass splitting Δmee2. 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, 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.
Published: 2016

40. Measurement of the Reactor Antineutrino Flux and Spectrum at Daya Bay

Author: An, FP, Balantekin, AB, Band, HR, Bishai, M, Blyth, S, Butorov, I, Cao, D, Cao, GF, Cao, J, Cen, WR, Chan, YL, Chang, JF, Chang, LC, Chang, Y, Chen, HS, Chen, QY, Chen, SM, Chen, YX, Chen, Y, Cheng, JH, Cheng, J, Cheng, YP, Cherwinka, JJ, Chu, MC, Cummings, JP, de Arcos, J, Deng, ZY, Ding, XF, Ding, YY, Diwan, MV, Dove, J, Draeger, E, Dwyer, DA, Edwards, WR, Ely, SR, Gill, R, Gonchar, M, Gong, GH, Gong, H, Grassi, M, Gu, WQ, Guan, MY, Guo, L, Guo, XH, Hackenburg, RW, Han, R, Hans, S, He, M, Heeger, KM, Heng, YK, Higuera, A, Hor, YK, Hsiung, YB, Hu, BZ, Hu, LM, Hu, LJ, Hu, T, Hu, W, Huang, EC, Huang, HX, Huang, XT, Huber, P, Hussain, G, Jaffe, DE, Jaffke, P, Jen, KL, Jetter, S, Ji, XP, Ji, XL, Jiao, JB, Johnson, RA, Kang, L, Kettell, SH, Kohn, S, Kramer, M, Kwan, KK, Kwok, MW, Kwok, T, Langford, TJ, Lau, K, Lebanowski, L, Lee, J, Lei, RT, Leitner, R, Leung, KY, Leung, JKC, Lewis, CA, Li, DJ, Li, F, Li, GS, Li, QJ, Li, SC, Li, WD, Li, XN, Li, XQ, Li, YF, Li, ZB, Liang, H, Lin, CJ, and Lin, GL
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, Daya Bay Collaboration, hep-ex, nucl-ex, physics.ins-det, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract: This Letter reports a measurement of the flux and energy spectrum of electron antineutrinos from six 2.9 GWth nuclear reactors with six detectors deployed in two near (effective baselines 512 and 561 m) and one far (1579 m) underground experimental halls in the Daya Bay experiment. Using 217 days of data, 296 721 and 41 589 inverse β decay (IBD) candidates were detected in the near and far halls, respectively. The measured IBD yield is (1.55±0.04) ×10(-18) cm(2) GW(-1) day(-1) or (5.92±0.14) ×10(-43) cm(2) fission(-1). This flux measurement is consistent with previous short-baseline reactor antineutrino experiments and is 0.946±0.022 (0.991±0.023) 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 2σ over the full energy range with a local significance of up to ∼4σ between 4-6 MeV. A reactor antineutrino spectrum of IBD reactions is extracted from the measured positron energy spectrum for model-independent predictions.
Published: 2016

41. Background radiation measurements at high power research reactors

Author: Ashenfelter, J, Balantekin, B, Baldenegro, CX, Band, HR, Barclay, G, Bass, CD, Berish, D, Bowden, NS, Bryan, CD, Cherwinka, JJ, Chu, R, Classen, T, Davee, D, Dean, D, Deichert, G, Dolinski, MJ, Dolph, J, Dwyer, DA, Fan, S, Gaison, JK, Galindo-Uribarri, A, Gilje, K, Glenn, A, Green, M, Han, K, Hans, S, Heeger, KM, Heffron, B, Jaffe, DE, Kettell, S, Langford, TJ, Littlejohn, BR, Martinez, D, McKeown, RD, Morrell, S, Mueller, PE, Mumm, HP, Napolitano, J, Norcini, D, Pushin, D, Romero, E, Rosero, R, Saldana, L, Seilhan, BS, Sharma, R, Stemen, NT, Surukuchi, PT, Thompson, SJ, Varner, RL, Wang, W, Watson, SM, White, B, White, C, Wilhelmi, J, Williams, C, Wise, T, Yao, H, Yeh, M, Yen, YR, Zhang, C, and Zhang, X
Subjects: Research reactors, Background measurements, Reactor antineutrino detection, Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Other Physical Sciences, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract: Research reactors host a wide range of activities that make use of the intense neutron fluxes generated at these facilities. Recent interest in performing measurements with relatively low event rates, e.g. reactor antineutrino detection, at these facilities necessitates a detailed understanding of background radiation fields. Both reactor-correlated and naturally occurring background sources are potentially important, even at levels well below those of importance for typical activities. Here we describe a comprehensive series of background assessments at three high-power research reactors, including γ-ray, neutron, and muon measurements. For each facility we describe the characteristics and identify the sources of the background fields encountered. The general understanding gained of background production mechanisms and their relationship to facility features will prove valuable for the planning of any sensitive measurement conducted therein.
Published: 2016

42. Light collection and pulse-shape discrimination in elongated scintillator cells for the PROSPECT reactor antineutrino experiment

Author: Ashenfelter, J, Balantekin, B, Band, HR, Barclay, G, Bass, CD, Berish, D, Bowden, NS, Bowes, A, Brodsky, JP, Bryan, CD, Cherwinka, JJ, Chu, R, Classen, T, Commeford, K, Davee, D, Dean, D, Deichert, G, Diwan, MV, Dolinski, MJ, Dolph, J, Dwyer, DA, Gaison, JK, Galindo-Uribarri, A, Gilje, K, Glenn, A, Goddard, BW, Green, M, Han, K, Hans, S, Heeger, KM, Heffron, B, Jaffe, DE, Langford, TJ, Littlejohn, BR, Caicedo, DAM, McKeown, RD, Mendenhall, MP, Mueller, P, Mumm, HP, Napolitano, J, Neilson, R, Norcini, D, Pushin, D, Qian, X, Romero, E, Rosero, R, Saldana, L, Seilhan, BS, Sharma, R, Sheets, S, Stemen, NT, Surukuchi, PT, Varner, RL, Viren, B, Wang, W, White, B, White, C, Wilhelmi, J, Williams, C, Wise, T, Yao, H, Yeh, M, Yen, YR, Zangakis, G, Zhang, C, and Zhang, X
Subjects: Neutrino detectors, Particle identification methods, Calorimeters, Nuclear & Particles Physics, Other Physical Sciences, Physical Sciences, Engineering
Abstract: A meter-long, 23-liter EJ-309 liquid scintillator detector has been constructed to study the light collection and pulse-shape discrimination performance of elongated scintillator cells for the PROSPECT reactor antineutrino experiment. The magnitude and uniformity of light collection and neutron-gamma discrimination power in the energy range of antineutrino inverse beta decay products have been studied using gamma and spontaneous fission calibration sources deployed along the cell axis. We also study neutron-gamma discrimination and light collection abilities for differing PMT and reflector configurations. Key design features for optimizing MeV-scale response and background rejection capabilities are identified.
Published: 2015

43. New Measurement of Antineutrino Oscillation with the Full Detector Configuration at Daya Bay

Author: An, FP, Balantekin, AB, Band, HR, Bishai, M, Blyth, S, Butorov, I, Cao, GF, Cao, J, Cen, WR, Chan, YL, Chang, JF, Chang, LC, Chang, Y, Chen, HS, Chen, QY, Chen, SM, Chen, YX, Chen, Y, Cheng, JH, Cheng, J, Cheng, YP, Cherwinka, JJ, Chu, MC, Cummings, JP, de Arcos, J, Deng, ZY, Ding, XF, Ding, YY, Diwan, MV, Draeger, E, Dwyer, DA, Edwards, WR, Ely, SR, Gill, R, Gonchar, M, Gong, GH, Gong, H, Grassi, M, Gu, WQ, Guan, MY, Guo, L, Guo, XH, Hackenburg, RW, Han, R, Hans, S, He, M, Heeger, KM, Heng, YK, Higuera, A, Hor, YK, Hsiung, YB, Hu, BZ, Hu, LM, Hu, LJ, Hu, T, Hu, W, Huang, EC, Huang, HX, Huang, XT, Huber, P, Hussain, G, Jaffe, DE, Jaffke, P, Jen, KL, Jetter, S, Ji, XP, Ji, XL, Jiao, JB, Johnson, RA, Kang, L, Kettell, SH, Kramer, M, Kwan, KK, Kwok, MW, Kwok, T, Langford, TJ, Lau, K, Lebanowski, L, Lee, J, Lei, RT, Leitner, R, Leung, KY, Leung, JKC, Lewis, CA, Li, DJ, Li, F, Li, GS, Li, QJ, Li, SC, Li, WD, Li, XN, Li, XQ, Li, YF, Li, ZB, Liang, H, Lin, CJ, Lin, GL, Lin, PY, Lin, SK, and Ling, JJ
Subjects: Daya Bay Collaboration, hep-ex, nucl-ex, physics.ins-det, Mathematical Sciences, Physical Sciences, Engineering, General Physics
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 6.9×10^{5} GW_{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 2 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}2θ_{13} and |Δm_{ee}^{2}| were halved as a result of these improvements. An analysis of the relative antineutrino rates and energy spectra between detectors gave sin^{2}2θ_{13}=0.084±0.005 and |Δm_{ee}^{2}|=(2.42±0.11)×10^{-3} eV^{2} in the three-neutrino framework.
Published: 2015

44. The muon system of the Daya Bay Reactor antineutrino experiment

Author: An, FP, Balantekin, AB, Band, HR, Beriguete, W, Bishai, M, Blyth, S, Brown, RE, Butorov, I, Cao, GF, Cao, J, Carr, R, Chan, YL, Chang, JF, Chang, L, Chang, Y, Chasman, C, Chen, HS, Chen, HY, Chen, QY, Chen, SJ, Chen, SM, Chen, XC, Chen, XH, Chen, Y, Chen, YX, Cheng, YP, Cherwinka, JJ, Chu, MC, Cummings, JP, Dale, E, De Arcos, J, Deng, ZY, Ding, YY, Diwan, MV, Draeger, E, Du, XF, Dwyer, DA, Edwards, WR, Ely, SR, Fu, JY, Ge, LQ, Gill, R, Goett, J, Gonchar, M, Gong, GH, Gong, H, Gu, WQ, Guan, MY, Guo, XH, Hackenburg, RW, Han, GH, Hans, S, He, M, He, Q, Heeger, KM, Heng, YK, Hinrichs, P, Hor, YK, Hsiung, YB, Hu, BZ, Hu, LJ, Hu, LM, Hu, T, Hu, W, Huang, EC, Huang, HX, Huang, HZ, Huang, XT, Huber, P, Hussain, G, Isvan, Z, Jaffe, DE, Jaffke, P, Jetter, S, Ji, XL, Ji, XP, Jiang, HJ, Jiao, JB, Johnson, RA, Kang, L, Kebwaro, JM, Kettell, SH, Kramer, M, Kwan, KK, Kwok, MW, Kwok, T, Lai, WC, Lai, WH, Lau, K, Lebanowski, L, Lee, J, Lei, RT, Leitner, R, Leung, A, Leung, JKC, Lewis, CA, Li, DJ, Li, F, Li, GS, and Li, QJ
Subjects: Neutrinos, Water shield, Cosmic ray, Muons, Underground, Nuclear & Particles Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Other Physical Sciences
Abstract: The Daya Bay experiment consists of functionally identical antineutrino detectors immersed in pools of ultrapure water in three well-separated underground experimental halls near two nuclear reactor complexes. These pools serve both as shields against natural, low-energy radiation, and as water Cherenkov detectors that efficiently detect cosmic muons using arrays of photomultiplier tubes. Each pool is covered by a plane of resistive plate chambers as an additional means of detecting muons. Design, construction, operation, and performance of these muon detectors are described.
Published: 2015

45. Independent measurement of the neutrino mixing angle theta(13) via neutron capture on hydrogen at Daya Bay

Author: An, FP, Balantekin, AB, Band, HR, Beriguete, W, Bishai, M, Blyth, S, Butorov, I, Cao, GF, Cao, J, Chan, YL, Chang, JF, Chang, LC, Chang, Y, Chasman, C, Chen, H, Chen, QY, Chen, SM, Chen, X, Chen, YX, Chen, Y, Cheng, YP, Cherwinka, JJ, Chu, MC, Cummings, JP, de Arcos, J, Deng, ZY, Ding, YY, Diwan, MV, Draeger, E, Du, XF, Dwyer, DA, Edwards, WR, Ely, SR, Fu, JY, Ge, LQ, Gill, R, Gonchar, M, Gong, GH, Gong, H, Gu, WQ, Guan, MY, Guo, XH, Hackenburg, RW, Han, GH, Hans, S, He, M, Heeger, M, Heng, YK, Hinrichs, P, Hor, YK, Hsiung, YB, Hu, BZ, Hu, LM, Hu, LJ, Hu, T, Hu, W, Huang, EC, Huang, H, Huang, XT, Huber, P, Hussain, G, Isvan, Z, Jaffe, DE, Jaffke, P, Jen, KL, Jetter, S, Ji, XP, Ji, XL, Jiang, HJ, Jiao, JB, Johnson, RA, Kang, L, Kettell, SH, Kramer, M, Kwan, KK, Kwok, MW, Kwok, T, Lai, WC, Lau, K, Lebanowski, L, Lee, J, Lei, RT, Leitner, R, Leung, A, Leung, JKC, Lewis, CA, Li, DJ, Li, F, Li, GS, Li, QJ, Li, WD, Li, XN, Li, XQ, Li, YF, Li, ZB, Liang, H, Lin, CJ, Lin, GL, and Lin, PY
Subjects: hep-ex, physics.ins-det, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics
Abstract: A new measurement of the $\theta_{13}$ mixing angle has been obtained at theDaya Bay Reactor Neutrino Experiment via the detection of inverse beta decaystagged by neutron capture on hydrogen. The antineutrino events for hydrogencapture are distinct from those for gadolinium capture with largely differentsystematic uncertainties, allowing a determination independent of thegadolinium-capture result and an improvement on the precision of $\theta_{13}$measurement. With a 217-day antineutrino data set obtained with sixantineutrino detectors and from six 2.9 GW$_{th}$ reactors, the rate deficitobserved at the far hall is interpreted as $\sin^22\theta_{13}=0.083\pm0.018$in the three-flavor oscillation model. When combined with thegadolinium-capture result from Daya Bay, we obtain$\sin^22\theta_{13}=0.089\pm0.008$ as the final result for thesix-antineutrino-detector configuration of the Daya Bay experiment.
Published: 2014

46. Independent measurement of the neutrino mixing angle θ13 via neutron capture on hydrogen at Daya Bay

Author: An, FP, Balantekin, AB, Band, HR, Beriguete, W, Bishai, M, Blyth, S, Butorov, I, Cao, GF, Cao, J, Chan, YL, Chang, JF, Chang, LC, Chang, Y, Chasman, C, Chen, H, Chen, QY, Chen, SM, Chen, X, Chen, YX, Chen, Y, Cheng, YP, Cherwinka, JJ, Chu, MC, Cummings, JP, de Arcos, J, Deng, ZY, Ding, YY, Diwan, MV, Draeger, E, Du, XF, Dwyer, DA, Edwards, WR, Ely, SR, Fu, JY, Ge, LQ, Gill, R, Gonchar, M, Gong, GH, Gong, H, Gu, WQ, Guan, MY, Guo, XH, Hackenburg, RW, Han, GH, Hans, S, He, M, Heeger, KM, Heng, YK, Hinrichs, P, Hor, YK, Hsiung, YB, Hu, BZ, Hu, LM, Hu, LJ, Hu, T, Hu, W, Huang, EC, Huang, H, Huang, XT, Huber, P, Hussain, G, Isvan, Z, Jaffe, DE, Jaffke, P, Jen, KL, Jetter, S, Ji, XP, Ji, XL, Jiang, HJ, Jiao, JB, Johnson, RA, Kang, L, Kettell, SH, Kramer, M, Kwan, KK, Kwok, MW, Kwok, T, Lai, WC, Lau, K, Lebanowski, L, Lee, J, Lei, RT, Leitner, R, Leung, A, Leung, JKC, Lewis, CA, Li, DJ, Li, F, Li, GS, Li, QJ, Li, WD, Li, XN, Li, XQ, Li, YF, Li, ZB, Liang, H, Lin, CJ, Lin, GL, and Lin, PY
Subjects: hep-ex, physics.ins-det, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics
Abstract: A new measurement of the $\theta_{13}$ mixing angle has been obtained at theDaya Bay Reactor Neutrino Experiment via the detection of inverse beta decaystagged by neutron capture on hydrogen. The antineutrino events for hydrogencapture are distinct from those for gadolinium capture with largely differentsystematic uncertainties, allowing a determination independent of thegadolinium-capture result and an improvement on the precision of $\theta_{13}$measurement. With a 217-day antineutrino data set obtained with sixantineutrino detectors and from six 2.9 GW$_{th}$ reactors, the rate deficitobserved at the far hall is interpreted as $\sin^22\theta_{13}=0.083\pm0.018$in the three-flavor oscillation model. When combined with thegadolinium-capture result from Daya Bay, we obtain$\sin^22\theta_{13}=0.089\pm0.008$ as the final result for thesix-antineutrino-detector configuration of the Daya Bay experiment.
Published: 2014

47. Search for a light sterile neutrino at Daya Bay.

Author: An, FP, Balantekin, AB, Band, HR, Beriguete, W, Bishai, M, Blyth, S, Butorov, I, Cao, GF, Cao, J, Chan, YL, Chang, JF, Chang, LC, Chang, Y, Chasman, C, Chen, H, Chen, QY, Chen, SM, Chen, X, Chen, YX, Chen, Y, Cheng, YP, Cherwinka, JJ, Chu, MC, Cummings, JP, de Arcos, J, Deng, ZY, Ding, YY, Diwan, MV, Draeger, E, Du, XF, Dwyer, DA, Edwards, WR, Ely, SR, Fu, JY, Ge, LQ, Gill, R, Gonchar, M, Gong, GH, Gong, H, Grassi, M, Gu, WQ, Guan, MY, Guo, XH, Hackenburg, RW, Han, GH, Hans, S, He, M, Heeger, KM, Heng, YK, Hinrichs, P, Hor, YK, Hsiung, YB, Hu, BZ, Hu, LM, Hu, LJ, Hu, T, Hu, W, Huang, EC, Huang, H, Huang, XT, Huber, P, Hussain, G, Isvan, Z, Jaffe, DE, Jaffke, P, Jen, KL, Jetter, S, Ji, XP, Ji, XL, Jiang, HJ, Jiao, JB, Johnson, RA, Kang, L, Kettell, SH, Kramer, M, Kwan, KK, Kwok, MW, Kwok, T, Lai, WC, Lau, K, Lebanowski, L, Lee, J, Lei, RT, Leitner, R, Leung, A, Leung, JKC, Lewis, CA, Li, DJ, Li, F, Li, GS, Li, QJ, Li, WD, Li, XN, Li, XQ, Li, YF, Li, ZB, Liang, H, Lin, CJ, and Lin, GL
Subjects: Daya Bay Collaboration, hep-ex, Mathematical Sciences, Physical Sciences, Engineering, General Physics
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(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(-3) eV(2)
Published: 2014

48. Spectral measurement of electron antineutrino oscillation amplitude and frequency at Daya Bay.

Author: An, FP, Balantekin, AB, Band, HR, Beriguete, W, Bishai, M, Blyth, S, Brown, RL, Butorov, I, Cao, GF, Cao, J, Carr, R, Chan, YL, Chang, JF, Chang, Y, Chasman, C, Chen, HS, Chen, HY, Chen, SJ, Chen, SM, Chen, XC, Chen, XH, Chen, Y, Chen, YX, Cheng, YP, Cherwinka, JJ, Chu, MC, Cummings, JP, de Arcos, J, Deng, ZY, Ding, YY, Diwan, MV, Draeger, E, Du, XF, Dwyer, DA, Edwards, WR, Ely, SR, Fu, JY, Ge, LQ, Gill, R, Gonchar, M, Gong, GH, Gong, H, Gornushkin, YA, Gu, WQ, Guan, MY, Guo, XH, Hackenburg, RW, Hahn, RL, Han, GH, Hans, S, He, M, Heeger, KM, Heng, YK, Hinrichs, P, Hor, Yk, Hsiung, YB, Hu, BZ, Hu, LJ, Hu, LM, Hu, T, Hu, W, Huang, EC, Huang, HX, Huang, HZ, Huang, XT, Huber, P, Hussain, G, Isvan, Z, Jaffe, DE, Jaffke, P, Jetter, S, Ji, XL, Ji, XP, Jiang, HJ, Jiao, JB, Johnson, RA, Kang, L, Kettell, SH, Kramer, M, Kwan, KK, Kwok, MW, Kwok, T, Lai, WC, Lai, WH, Lau, K, Lebanowski, L, Lee, J, Lei, RT, Leitner, R, Leung, A, Leung, JKC, Lewis, CA, Li, DJ, Li, F, Li, GS, Li, QJ, Li, WD, Li, XN, Li, XQ, and Li, YF
Subjects: Daya Bay Collaboration, hep-ex, nucl-ex, General Physics, Mathematical Sciences, Physical Sciences, Engineering
Abstract: A measurement of the energy dependence of antineutrino disappearance at the Daya Bay reactor neutrino experiment is reported. Electron antineutrinos (ν¯(e)) from six 2.9 GW(th) reactors were detected with six detectors deployed in two near (effective baselines 512 and 561 m) and one far (1579 m) underground experimental halls. Using 217 days of data, 41 589 (203 809 and 92 912) antineutrino candidates were detected in the far hall (near halls). An improved measurement of the oscillation amplitude sin(2)2θ(13)=0.090(-0.009)(+0.008) and the first direct measurement of the ν¯(e) mass-squared difference |Δm(ee)2|=(2.59(-0.20)(+0.19))×10(-3) eV2 is obtained using the observed ν¯(e) rates and energy spectra in a three-neutrino framework. This value of |Δm(ee)2| is consistent with |Δm(μμ)2| measured by muon neutrino disappearance, supporting the three-flavor oscillation model.
Published: 2014

49. Results from the Daya Bay Reactor Neutrino Experiment

Author: Tsang, KV, An, FP, An, Q, Bai, JZ, Balantekin, AB, Band, HR, Beriguete, W, Bishai, M, Blyth, S, Brown, RL, Cao, GF, Cao, J, Carr, R, Chan, WT, Chang, JF, Chang, Y, Chasman, C, Chen, HS, Chen, HY, Chen, SJ, Chen, SM, Chen, XC, Chen, XH, Chen, XS, Chen, Y, Chen, YX, Cherwinka, JJ, Chu, MC, Cummings, JP, Deng, ZY, Ding, YY, Diwan, MV, Draeger, E, Du, XF, Dwyer, D, Edwards, WR, Ely, SR, Fang, SD, Fu, JY, Fu, ZW, Ge, LQ, Gill, RL, Gonchar, M, Gong, GH, Gong, H, Gornushkin, YA, Gu, WQ, Guan, MY, Guo, XH, Hackenburg, RW, Hahn, RL, Hans, S, Hao, HF, He, M, He, Q, Heeger, KM, Heng, YK, Hinrichs, P, Hor, YK, Hsiung, YB, Hu, BZ, Hu, T, Huang, HX, Huang, HZ, Huang, XT, Huber, P, Issakov, V, Isvan, Z, Jaffe, DE, Jetter, S, Ji, XL, Ji, XP, Jiang, HJ, Jiao, JB, Johnson, RA, Kang, L, Kettell, SH, Kramer, M, Kwan, KK, Kwok, MW, Kwok, T, Lai, CY, Lai, WC, Lai, WH, Lau, K, Lebanowski, L, Lee, J, Lei, RT, Leitner, R, Leung, JKC, Leung, KY, Lewis, CA, Li, F, Li, GS, Li, QJ, Li, WD, Li, XB, Li, XN, Li, XQ, and Li, Y
Subjects: Neutrino Oscillation, Neutrino Mixing, Reactor, Daya Bay
Abstract: The Daya Bay Reactor Neutrino Experiment was designed to achieve a sensitivity on the value of sin22θ13 to better than 0.01 at 90% CL. The experiment consists of eight antineutrino detectors installed underground at different baselines from six nuclear reactors. With data collected with six antineutrino detectors for 55 days, Daya Bay announced the discovery of a non-zero value for sin22θ13 with a significance of 5.2 standard deviations in March 2012. The most recent analysis with 139 days of data acquired in a six-detector configuration yields sin22θ13=0.089±0.010(stat.)±0.005(syst.), which is the most precise measurement of sin22θ13 to date. © 2013.
Published: 2014

50. Assembly and Installation of the Daya Bay Antineutrino Detectors

Author: Band, HR, Brown, RL, Carr, R, Chen, XC, Chen, XH, Cherwinka, JJ, Chu, MC, Draeger, E, Dwyer, DA, Edwards, WR, Gill, R, Goett, J, Greenler, LS, Gu, WQ, He, WS, Heeger, KM, Heng, YK, Hinrichs, P, Ho, TH, Hoff, M, Hsiung, YB, Jin, Y, Kang, L, Kettell, SH, Kramer, M, Kwan, KK, Kwok, MW, Lewis, CA, Li, GS, Li, N, Li, SF, Li, XN, Lin, CJ, Littlejohn, BR, Liu, JL, Luk, KB, Luo, XL, Y, X, McFarlane, MC, McKeown, RD, Nakajima, Y, Ochoa-Ricoux, JP, Pagac, A, Qian, X, Seilhan, B, Shih, K, Steiner, H, Tang, X, Themann, H, Tsang, KV, Tsang, RHM, Virostek, S, Wang, L, Wang, W, Wang, ZM, Webber, DM, Wei, YD, Wen, LJ, Wenman, DL, Wilhelmi, J, Wingert, M, Wise, T, Wong, HLH, Wu, FF, Xiao, Q, Yang, L, Zhang, ZJ, Zhong, WL, and Zhuang, HL
Subjects: Large detector systems for particle and astroparticle physics, Neutrino detectors, Detector alignment and calibration methods, physics.ins-det, hep-ex, nucl-ex, Physical Sciences, Engineering, Nuclear & Particles Physics
Abstract: The Daya Bay reactor antineutrino experiment is designed to make a precision measurement of the neutrino mixing angle θ13, and recently made the definitive discovery of its non-zero value. It utilizes a set of eight, functionally identical antineutrino detectors to measure the reactor flux and spectrum at baselines of ∼ 300-2000 m from the Daya Bay and Ling Ao Nuclear Power Plants. The Daya Bay antineutrino detectors were built in an above-ground facility and deployed side-by-side at three underground experimental sites near and far from the nuclear reactors. This configuration allows the experiment to make a precision measurement of reactor antineutrino disappearance over km-long baselines and reduces relative systematic uncertainties between detectors and nuclear reactors. This paper describes the assembly and installation of the Daya Bay antineutrino detectors. © 2013 IOP Publishing Ltd and Sissa Medialab srl.
Published: 2013

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