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17,720 results on '"Huang D"'

151. Fast and Flexible Analysis of Direct Dark Matter Search Data with Machine Learning

Author

LUX Collaboration, Akerib, D. S., Alsum, S., Araújo, H. M., Bai, X., Balajthy, J., Bang, J., Baxter, A., Bernard, E. P., Bernstein, A., Biesiadzinski, T. P., Boulton, E. M., Boxer, B., Brás, P., Burdin, S., Byram, D., Carrara, N., Carmona-Benitez, M. C., Chan, C., Cutter, J. E., de Viveiros, L., Druszkiewicz, E., Ernst, J., Fan, A., Fiorucci, S., Gaitskell, R. J., Ghag, C., Gilchriese, M. G. D., Gwilliam, C., Hall, C. R., Haselschwardt, S. J., Hertel, S. A., Hogan, D. P., Horn, M., Huang, D. Q., Ignarra, C. M., Jacobsen, R. G., Jahangir, O., Ji, W., Kamdin, K., Kazkaz, K., Khaitan, D., Korolkova, E. V., Kravitz, S., Kudryavtsev, V. A., Leason, E., Lenardo, B. G., Lesko, K. T., Liao, J., Lin, J., Lindote, A., Lopes, M. I., Manalaysay, A., Mannino, R. L., Marangou, N., McKinsey, D. N., Mei, D. -M., Morad, J. A., Murphy, A. St. J., Naylor, A., Nehrkorn, C., Nelson, H. N., Neves, F., Nilima, A., Oliver-Mallory, K. C., Palladino, K. J., Rhyne, C., Riffard, Q., Rischbieter, G. R. C., Rossiter, P., Shaw, S., Shutt, T. A., Silva, C., Solmaz, M., Solovov, V. N., Sorensen, P., Sumner, T. J., Swanson, N., Szydagis, M., Taylor, D. J., Taylor, R., Taylor, W. C., Tennyson, B. P., Terman, P. A., Tiedt, D. R., To, W. H., Tvrznikova, L., Utku, U., Vacheret, A., Vaitkus, A., Velan, V., Webb, R. C., White, J. T., Whitis, T. J., Witherell, M. S., Wolfs, F. L. H., Woodward, D., Xian, X., Xu, J., and Zhang, C.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, High Energy Physics - Experiment, Physics - Instrumentation and Detectors
Abstract

We present the results from combining machine learning with the profile likelihood fit procedure, using data from the Large Underground Xenon (LUX) dark matter experiment. This approach demonstrates reduction in computation time by a factor of 30 when compared with the previous approach, without loss of performance on real data. We establish its flexibility to capture non-linear correlations between variables (such as smearing in light and charge signals due to position variation) by achieving equal performance using pulse areas with and without position-corrections applied. Its efficiency and scalability furthermore enables searching for dark matter using additional variables without significant computational burden. We demonstrate this by including a light signal pulse shape variable alongside more traditional inputs such as light and charge signal strengths. This technique can be exploited by future dark matter experiments to make use of additional information, reduce computational resources needed for signal searches and simulations, and make inclusion of physical nuisance parameters in fits tractable.

Published
2022
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152. Cosmogenic production of $^{37}$Ar in the context of the LUX-ZEPLIN experiment

Author

Aalbers, J., Akerib, D. S., Musalhi, A. K. Al, Alder, F., Alsum, S. K., Amarasinghe, C. S., Ames, A., Anderson, T. J., Angelides, N., Araújo, H. M., Armstrong, J. E., Arthurs, M., Bai, X., Baker, A., Balajthy, J., Balashov, S., Bang, J., Bargemann, J. W., Bauer, D., Baxter, A., Beattie, K., Bernard, E. P., Bhatti, A., Biekert, A., Biesiadzinski, T. P., Birch, H. J., Blockinger, G. M., Bodnia, E., Boxer, B., Brew, C. A. J., Brás, P., Burdin, S., Busenitz, J. K., Buuck, M., Cabrita, R., Carmona-Benitez, M. C., Cascella, M., Chan, C., Chawla, A., Chen, H., Chott, N. I., Cole, A., Converse, M. V., Cottle, A., Cox, G., Creaner, O., Cutter, J. E., Dahl, C. E., David, A., de Viveiros, L., Dobson, J. E. Y., Druszkiewicz, E., Eriksen, S. R., Fan, A., Fayer, S., Fearon, N. M., Fiorucci, S., Flaecher, H., Fraser, E. D., Fruth, T., Gaitskell, R. J., Genovesi, J., Ghag, C., Gibson, E., Gilchriese, M. G. D., Gokhale, S., van der Grinten, M. G. D., Gwilliam, C. B., Hall, C. R., Haselschwardt, S. J., Hertel, S. A., Horn, M., Huang, D. Q., Hunt, D., Ignarra, C. M., Jahangir, O., James, R. S., Ji, W., Johnson, J., Kaboth, A. C., Kamaha, A. C., Kamdin, K., Khaitan, D., Khazov, A., Khurana, I., Kodroff, D., Korley, L., Korolkova, E. V., Kraus, H., Kravitz, S., Kreczko, L., Kudryavtsev, V. A., Leason, E. A., Leonard, D. S., Lesko, K. T., Levy, C., Lee, J., Lin, J., Lindote, A., Linehan, R., Lippincott, W. H., Liu, X., Lopes, M. I., Asamar, E. Lopez, Lopez-Paredes, B., Lorenzon, W., Luitz, S., Majewski, P. A., Manalaysay, A., Manenti, L., Mannino, R. L., Marangou, N., McCarthy, M. E., McKinsey, D. N., McLaughlin, J., Miller, E. H., Mizrachi, E., Monte, A., Monzani, M. E., Morad, J. A., Mendoza, J. D. Morales, Morrison, E., Mount, B. J., Murphy, A. St. J., Naim, D., Naylor, A., Nedlik, C., Nelson, H. N., Neves, F., Nikoleyczik, J. A., Nilima, A., Olcina, I., Oliver-Mallory, K., Pal, S., Palladino, K. J., Palmer, J., Parveen, N., Patton, S. J., Pease, E. K., Penning, B., Pereira, G., Perry, E., Pershing, J., Piepke, A., Porzio, D., Qie, Y., Reichenbacher, J., Rhyne, C. A., Richards, A., Riffard, Q., Riffard, %Q., Rischbieter, G. R. C., Rosero, R., Rossiter, P., Rushton, T., Santone, D., Sazzad, A. B. M. R., Schnee, R. W., Scovell, P. R., Shaw, S., Shutt, T. A., Silk, J. J., Silva, C., Sinev, G., Smith, R., Solmaz, M., Solovov, V. N., Sorensen, P., Soria, J., Stancu, I., Stevens, A., Stifter, K., Suerfu, B., Sumner, T. J., Swanson, N., Szydagis, M., Taylor, W. C., Taylor, R., Temples, D. J., Terman, P. A., Tiedt, D. R., Timalsina, M., To, W. H., Tong, Z., Tovey, D. R., Trask, M., Tripathi, M., Tronstad, D. R., Turner, W., Utku, U., Vaitkus, A., Wang, B., Wang, Y., Wang, J. J., Wang, W., Watson, J. R., Webb, R. C., White, R. G., Whitis, T. J., Williams, M., Wolfs, F. L. H., Woodford, S., Woodward, D., Wright, C. J., Xia, Q., Xiang, X., Xu, J., and Yeh, M.

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

We estimate the amount of $^{37}$Ar produced in natural xenon via cosmic ray-induced spallation, an inevitable consequence of the transportation and storage of xenon on the Earth's surface. We then calculate the resulting $^{37}$Ar concentration in a 10-tonne payload~(similar to that of the LUX-ZEPLIN experiment) assuming a representative schedule of xenon purification, storage and delivery to the underground facility. Using the spallation model by Silberberg and Tsao, the sea level production rate of $^{37}$Ar in natural xenon is estimated to be 0.024~atoms/kg/day. Assuming the xenon is successively purified to remove radioactive contaminants in 1-tonne batches at a rate of 1~tonne/month, the average $^{37}$Ar activity after 10~tonnes are purified and transported underground is 0.058--0.090~$\mu$Bq/kg, depending on the degree of argon removal during above-ground purification. Such cosmogenic $^{37}$Ar will appear as a noticeable background in the early science data, while decaying with a 35~day half-life. This newly-noticed production mechanism of $^{37}$Ar should be considered when planning for future liquid xenon-based experiments.

Published
2022
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154. Study of the Very High Energy emission of M87 through its broadband spectral energy distribution

Author

HAWC Collaboration, Alfaro, R., Alvarez, C., Arteaga-Velázquez, J. C., Rojas, D. Avila, Solares, H. A. Ayala, Belmont-Moreno, E., Capistrán, T., Carramiñana, A., Casanova, S., Cotti, U., Cotzomi, J., de León, S. Coutiño, De la Fuente, E., de León, C., Hernandez, R. Diaz, DuVernois, M. A., Durocher, M., Díaz-Vélez, J. C., Espinoza, C., Fan, K. L., Alonso, M. Fernández, Fraija, N., García-González, J. A., Garfias, F., González, M. M., Goodman, J. A., Harding, J. P., Huang, D., Hueyotl-Zahuantitla, F., Hüntemeyer, P., Joshi, V., Vargas, H. León, Linnemann, J. T., Longinotti, A. L., Luis-Raya, G., Malone, K., Martinez, O., Martínez-Castro, J., Matthews, J. A., Miranda-Romagnoli, P., Moreno, E., Mostafá, M., Nayerhoda, A., Nellen, L., Noriega-Papaqui, R., Omodei, N., Peisker, A., Pérez-Pérez, E. G., Rho, C. D., Rosa-González, D., Salazar, H., Salazar-Gallegos, D., Greus, F. Salesa, Sandoval, A., Serna-Franco, J., Son, Y., Springer, R. W., Tibolla, O., Tollefson, K., Torres, I., Ureña-Mena, F., Villaseñor, L., Wang, X., Willox, E., and Zepeda, A.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The radio galaxy M87 is the central dominant galaxy of the Virgo Cluster. Very High Energy (VHE,$\gtrsim 0.1$ TeV) emission, from M87 has been detected by Imaging Air Cherenkov Telescopes (IACTs ). Recently, marginal evidence for VHE long-term emission has also been observed by the High Altitude Water Cherenkov (HAWC) Observatory, a gamma ray and cosmic-ray detector array located in Puebla, Mexico. The mechanism that produces VHE emission in M87 remains unclear. This emission is originated in its prominent jet, which has been spatially resolved from radio to X-rays. In this paper, we constructed a spectral energy distribution from radio to gamma rays that is representative of the non-flaring activity of the source, and in order to explain the observed emission, we fit it with a lepto-hadronic emission model. We found that this model is able to explain non-flaring VHE emission of M87 as well as an orphan flare reported in 2005., Comment: submitted to ApJ

Published
2021

155. HAWC Study of the Ultra-High-Energy Spectrum of MGRO J1908+06

Author

HAWC Collaboration, Albert, A., Alfaro, R., Alvarez, C., Álvarez, J. D., Camacho, J. R. Angeles, Arteaga-Velázquez, J. C., Rojas, D. Avila, Solares, H. A. Ayala, Babu, R., Belmont-Moreno, E., Brisbois, C., Caballero-Mora, K. S., Capistrán, T., Carramiñana, A., Casanova, S., Cotti, U., Cotzomi, J., de León, S. Coutiño, De la Fuente, E., de León, C., Hernandez, R. Diaz, Dingus, B. L., DuVernois, M. A., Durocher, M., Díaz-Vélez, J. C., Engel, K., Espinoza, C., Fan, K. L., Fang, K., Alonso, M. Fernández, Fraija, N., Garcia, D., García-González, J. A., Garfias, F., Giacinti, G., Goksu, H., González, M. M., Goodman, J. A., Harding, J. P., Hinton, J., Hona, B., Huang, D., Hueyotl-Zahuantitla, F., Hüntemeyer, P., Iriarte, A., Jardin-Blicq, A., Joshi, V., Kaufmann, S., Kieda, D., Lee, W. H., Lee, J., Vargas, H. León, Linnemann, J. T., Longinotti, A. L., Luis-Raya, G., Malone, K., Marandon, V., Martinez, O., Martínez-Castro, J., Matthews, J. A., Miranda-Romagnoli, P., Morales-Soto, J. A., Moreno, E., Mostafá, M., Nayerhoda, A., Nellen, L., Newbold, M., Nisa, M. U., Noriega-Papaqui, R., Olivera-Nieto, L., Omodei, N., Peisker, A., Araujo, Y. Pérez, Pérez-Pérez, E. G., Rho, C. D., Rosa-González, D., Salazar, H., Greus, F. Salesa, Sandoval, A., Schneider, M., Schoorlemmer, H., Serna-Franco, J., Smith, A. J., Son, Y., Springer, R. W., Tibolla, O., Tollefson, K., Torres, I., Torres-Escobedo, R., Turner, R., Ureña-Mena, F., Villaseñor, L., Wang, X., Watson, I. J., Willox, E., Zepeda, A., Zhou, H., Li, M. Breuhaus H., and Zhang, H.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We report TeV gamma-ray observations of the ultra-high-energy source MGRO J1908+06 using data from the High Altitude Water Cherenkov (HAWC) Observatory. This source is one of the highest-energy known gamma-ray sources, with emission extending past 200 TeV. Modeling suggests that the bulk of the TeV gamma-ray emission is leptonic in nature, driven by the energetic radio-faint pulsar PSR J1907+0602. Depending on what assumptions are included in the model, a hadronic component may also be allowed. Using the results of the modeling, we discuss implications for detection prospects by multi-messenger campaigns., Comment: accepted by ApJ, in press

Published
2021
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158. Peta-electron volt gamma-ray emission from the Crab Nebula

Author

The LHAASO Collaboration, Cao, Zhen, Aharonian, F., An, Q., Axikegu, Bai, L. X., Bai, Y. X., Bao, Y. W., Bastieri, D., Bi, X. J., Bi, Y. J., Cai, H., Cai, J. T., Cao, Zhe, Chang, J., Chang, J. F., Chen, B. M., Chen, E. S., Chen, J., Chen, Liang, Chen, Long, Chen, M. J., Chen, M. L., Chen, Q. H., Chen, S. H., Chen, S. Z., Chen, T. L., Chen, X. L., Chen, Y., Cheng, N., Cheng, Y. D., Cui, S. W., Cui, X. H., Cui, Y. D., Piazzoli, B. D'Ettorre, Dai, B. Z., Dai, H. L., Dai, Z. G., Danzengluobu, della Volpe, D., Dong, X. J., Duan, K. K., Fan, J. H., Fan, Y. Z., Fan, Z. X., Fang, J., Fang, K., Feng, C. F., Feng, L., Feng, S. H., Feng, Y. L., Gao, B., Gao, C. D., Gao, L. Q., Gao, Q., Gao, W., Ge, M. M., Geng, L. S., Gong, G. H., Gou, Q. B., Gu, M. H., Guo, F. L., Guo, J. G., Guo, X. L., Guo, Y. Q., Guo, Y. Y., Han, Y. A., He, H. H., He, H. N., He, J. C., He, S. L., He, X. B., He, Y., Heller, M., Hor, Y. K., Hou, C., Hou, X., Hu, H. B., Hu, S., Hu, S. C., Hu, X. J., Huang, D. H., Huang, Q. L., Huang, W. H., Huang, X. T., Huang, X. Y., Huang, Z. C., Ji, F., Ji, X. L., Jia, H. Y., Jiang, K., Jiang, Z. J., Jin, C., Ke, T., Kuleshov, D., Levochkin, K., Li, B. B., Li, Cheng, Li, Cong, Li, F., Li, H. B., Li, H. C., Li, H. Y., Li, Jie, Li, Jian, Li, K., Li, W. L., Li, X. R., Li, Xin, Li, Y., Li, Y. Z., Li, Zhe, Li, Zhuo, Liang, E. W., Liang, Y. F., Lin, S. J., Liu, B., Liu, C., Liu, D., Liu, H., Liu, H. D., Liu, J., Liu, J. L., Liu, J. S., Liu, J. Y., Liu, M. Y., Liu, R. Y., Liu, S. M., Liu, W., Liu, Y., Liu, Y. N., Liu, Z. X., Long, W. J., Lu, R., Lv, H. K., Ma, B. Q., Ma, L. L., Ma, X. H., Mao, J. R., Masood, A., Min, Z., Mitthumsiri, W., Montaruli, T., Nan, Y. C., Pang, B. Y., Pattarakijwanich, P., Pei, Z. Y., Qi, M. Y., Qi, Y. Q., Qiao, B. Q., Qin, J. J., Ruffolo, D., Rulev, V., Sáiz, A., Shao, L., Shchegolev, O., Sheng, X. D., Shi, J. Y., Song, H. C., Stenkin, Yu. V., Stepanov, V., Su, Y., Sun, Q. N., Sun, X. N., Sun, Z. B., Tam, P. H. T., Tang, Z. B., Tian, W. W., Wang, B. D., Wang, C., Wang, H., Wang, H. G., Wang, J. C., Wang, J. S., Wang, L. P., Wang, L. Y., Wang, R. N., Wang, Wei, Wang, X. G., Wang, X. J., Wang, X. Y., Wang, Y., Wang, Y. D., Wang, Y. J., Wang, Y. P., Wang, Z. H., Wang, Z. X., Wang, Zhen, Wang, Zheng, Wei, D. M., Wei, J. J., Wei, Y. J., Wen, T., Wu, C. Y., Wu, H. R., Wu, S., Wu, W. X., Wu, X. F., Xi, S. Q., Xia, J., Xia, J. J., Xiang, G. M., Xiao, D. X., Xiao, G., Xiao, H. B., Xin, G. G., Xin, Y. L., Xing, Y., Xu, D. L., Xu, R. X., Xue, L., Yan, D. H., Yan, J. Z., Yang, C. W., Yang, F. F., Yang, J. Y., Yang, L. L., Yang, M. J., Yang, R. Z., Yang, S. B., Yao, Y. H., Yao, Z. G., Ye, Y. M., Yin, L. Q., Yin, N., You, X. H., You, Z. Y., Yu, Y. H., Yuan, Q., Zeng, H. D., Zeng, T. X., Zeng, W., Zeng, Z. K., Zha, M., Zhai, X. X., Zhang, B. B., Zhang, H. M., Zhang, H. Y., Zhang, J. L., Zhang, J. W., Zhang, L. X., Zhang, Li, Zhang, Lu, Zhang, P. F., Zhang, P. P., Zhang, R., Zhang, S. R., Zhang, S. S., Zhang, X., Zhang, X. P., Zhang, Y. F., Zhang, Y. L., Zhang, Yi, Zhang, Yong, Zhao, B., Zhao, J., Zhao, L., Zhao, L. Z., Zhao, S. P., Zheng, F., Zheng, Y., Zhou, B., Zhou, H., Zhou, J. N., Zhou, P., Zhou, R., Zhou, X. X., Zhu, C. G., Zhu, F. R., Zhu, H., Zhu, K. J., and Zuo, X.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The Crab pulsar and the surrounding nebula powered by the pulsar's rotational energy through the formation and termination of a relativistic electron-positron wind is a bright source of gamma-rays carrying crucial information about this complex conglomerate. We report the detection of $\gamma$-rays with a spectrum showing gradual steepening over three energy decades, from $5\times 10^{-4}$ to $1.1$ petaelectronvolt (PeV). The ultra-high-energy photons exhibit the presence of a PeV electron accelerator (a pevatron) with an acceleration rate exceeding 15% of the absolute theoretical limit. Assuming that unpulsed $\gamma$-rays are produced at the termination of the pulsar's wind, we constrain the pevatron's size, between $0.025$ and $0.1$ pc, and the magnetic field $\approx 110 \mu$G. The production rate of PeV electrons, $2.5 \times 10^{36}$ erg $\rm s^{-1}$, constitutes 0.5% of the pulsar's spin-down luminosity, although we do not exclude a non-negligible contribution of PeV protons to the production of the highest energy $\gamma$-rays., Comment: 43 pages, 13 figures, 2 tables; Published in Science

Published
2021
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159. Rapid and Accurate Detection of SARS-CoV-2 Mutations using a Cas12a-based Sensing Platform

Author

He, C, Lin, C, Mo, G, Xi, B, Li, A, Huang, D, Wan, Y, Chen, F, Liang, Y, Zuo, Q, Xu, W, Feng, D, Zhang, G, Han, L, Ke, C, Du, H, and Huang, L

Subjects
Quantitative Biology - Quantitative Methods, Quantitative Biology - Biomolecules
Abstract

The increasing prevalence of SARS-CoV-2 variants with spike mutations has raised concerns owing to higher transmission rates, disease severity, and escape from neutralizing antibodies. Rapid and accurate detection of SARS-CoV-2 variants provides crucial information concerning the outbreaks of SARS-CoV-2 variants and possible lines of transmission. This information is vital for infection prevention and control. We used a Cas12a-based RT-PCR combined with CRISPR on-site rapid detection system (RT-CORDS) platform to detect the key mutations in SARS-COV-2 variants, such as 69/70 deletion, N501Y, and D614G. We used type-specific CRISPR RNAs (crRNAs) to identify wild-type (crRNA-W) and mutant (crRNA-M) sequences of SARS-CoV-2. We successfully differentiated mutant variants from wild-type SARS-CoV-2 with a sensitivity of $10^{-17}$ M (approximately 6 copies/$\mu$L). The assay took just 10 min with the Cas12a/crRNA reaction after a simple RT-PCR using a fluorescence reporting system. In addition, a sensitivity of $10^{-16}$ M could be achieved when lateral flow strips were used as readouts. The accuracy of RT-CORDS for SARS-CoV-2 variant detection was 100% consistent with the sequencing data. In conclusion, using the RT-CORDS platform, we accurately, sensitively, specifically, and rapidly detected SARS-CoV-2 variants. This method may be used in clinical diagnosis., Comment: 39 pages, 6 figures

Published
2021

160. Decadal stability in coral cover could mask hidden changes on reefs in the East Asian Seas

Author

Chan, Y. K. S., Affendi, Y. A., Ang, P. O., Baria-Rodriguez, M. V., Chen, C. A., Chui, A. P. Y., Giyanto, Glue, M., Huang, H., Kuo, C-Y., Kim, S. W., Lam, V. Y. Y., Lane, D. J. W., Lian, J. S., Lin, S. M. N. N., Lunn, Z., Nañola, Jr, C. L., Nguyen, V. L., Park, H. S., Suharsono, Sutthacheep, M., Vo, S. T., Vibol, O., Waheed, Z., Yamano, H., Yeemin, T., Yong, E., Kimura, T., Tun, K., Chou, L. M., and Huang, D.

Published
2023
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161. Quantum fluctuations of charge order induce phonon softening in a superconducting cuprate

Author

Huang, H. Y., Singh, A., Mou, C. Y., Johnston, S., Kemper, A. F., Brink, J. van den, Chen, P. J., Lee, T. K., Okamoto, J., Chu, Y. Y., Li, J. H., Komiya, S., Komarek, A. C., Fujimori, A., Chen, C. T., and Huang, D. J.

Subjects
Condensed Matter - Superconductivity
Abstract

Quantum phase transitions play an important role in shaping the phase diagram of high-temperature cuprate superconductors. These cuprates possess intertwined orders which interact strongly with superconductivity. However, the evidence for the quantum critical point associated with the charge order in the superconducting phase remains elusive. Here we show the short-range charge orders and the spectral signature of the quantum fluctuations in La$_{2-x}$Sr$_x$CuO$_4$ (LSCO) near the optimal doping using high-resolution resonant inelastic X-ray scattering. On performing calculations through a diagrammatic framework, we discovered that the charge correlations significantly soften several branches of phonons. These results elucidate the role of charge order in the LSCO compound, providing evidence for quantum critical scaling and discommensurations associated with charge order., Comment: 9 pages, 4 figures

Published
2021
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162. Characterization of the background for a neutrino search with the HAWC observatory

Author

HAWC Collaboration, Albert, A., Alfaro, R., Alvarez, C., Camacho, J. R. Angeles, Arteaga-Velázquez, J. C., Arunbabu, K. P., Belmont-Moreno, E., Caballero-Mora, K. S., Capistrán, T., Carramiñana, A., Casanova, S., Cotti, U., Cotzomi, J., de León, S. Coutiño, De la Fuente, E., Hernandez, R. Diaz, DuVernois, M. A., Durocher, M., Espinoza, C., Fan, K. L., Fraija, N., Garcia, D., García-González, J. A., Garfias, F., González, M. M., Goodman, J. A., Huang, D., Hueyotl-Zahuantitla, F., Hüntemeyer, P., Iriarte, A., Jardin-Blicq, A., Kieda, D., Lara, A., Lee, W. H., Vargas, H. León, Longinotti, A. L., Luis-Raya, G., Malone, K., Martínez-Castro, J., Matthews, J. A., Miranda-Romagnoli, P., Morales-Soto, J. A., Moreno, E., Nayerhoda, A., Nellen, L., Noriega-Papaqui, R., Omodei, N., Peisker, A., Pérez-Pérez, E. G., Rho, C. D., Rosa-González, D., Sandoval, A., Serna-Franco, J., Springer, R. W., Tollefson, K., Torres, I., Torres-Escobedo, R., Ureña-Mena, F., Villaseñor, L., Zhou, H., and de León, C.

Subjects
High Energy Physics - Experiment, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The close location of the HAWC observatory to the largest volcano in Mexico allows to perform a search for neutrino-induced horizontal muon and tau charged leptons. The section of the volcano located at the horizon reaches values of slant depth larger than 8 km of rock, making it an excellent shield for the cosmic ray horizontal background. We report the search method and background suppression technique developed for the detection of Earth-skimming neutrinos with HAWC, as well as a model that describes the remaining background produced by scattered muons. We show that by increasing the detection energy threshold we could use HAWC to search for neutrino-induced charged leptons., Comment: Replaced with the accepted version. Added the journal reference and DOI

Published
2021
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163. TeV emission of Galactic plane sources with HAWC and H.E.S.S

Author

Abdalla, H., Aharonian, F., Benkhali, F. Ait, Angüner, E. O., Arcaro, C., Armand, C., Armstrong, T., Ashkar, H., Backes, M., Baghmanyan, V., Martins, V. Barbosa, Barnacka, A., Barnard, M., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Breuhaus, M., Brose, R., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, T., Bylund, T., Caroff, S., Carosi, A., Chand, T., Chandra, S., Chen, A., Cotter, G., Curyło, M., Mbarubucyeye, J. Damascene, Davids, I. D., Davies, J., Deil, C., Devin, J., Dirson, L., Djannati-Ataï, A., Dmytriiev, A., Donath, A., Doroshenko, V., Dreyer, L., Duffy, C., Dyks, J., Egberts, K., Eichhorn, F., Einecke, S., Emery, G., Ernenwein, J. -P., Feijen, K., Fegan, S., Fiasson, A., de Clairfontaine, G. Fichet, Fontaine, G., Funk, S., Füßling, M., Gabici, S., Gallant, Y. A., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H., Hahn, J., Haupt, M., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Hörbe, M., Horns, D., Huber, D., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jung-Richardt, I., Kasai, E., Kastendieck, M. A., Katarzyński, K., Katz, U., Khangulyan, D., Khélifi, B., Klepser, S., Kluźniak, W., Komin, Nu., Konno, R., Kosack, K., Kostunin, D., Kreter, M., Lamanna, G., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leuschner, F., Levy, C., Lohse, T., Lypova, I., Mackey, J., Majumdar, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Mares, A., Martí-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Meyer, M., Mitchell, A. M. W., Moderski, R., Mohrmann, L., Montanari, A., Moore, C., Morris, P., Moulin, E., Muller, J., Murach, T., Nakashima, K., Nayerhoda, A., de Naurois, M., Ndiyavala, H., Niemiec, J., Oakes, L., Brien, P. O, Odaka, H., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Peron, G., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Noel, A. Priyana, Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reichherzer, P., Reimer, A., Reimer, O., Remy, Q., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Sahakian, V., Sailer, S., Salzmann, H., Sanchez, D. A., Santangelo, A., Sasaki, M., Schäfer, J., Schüssler, F., Schutte, H. M., Schwanke, U., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shapopi, J. N. S., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Specovius, A., Spencer, S., Spir-Jacob, M., Stawarz, Ł., Sun, L., Steenkamp, R., Stegmann, C., Steinmassl, S., Steppa, C., Takahashi, T., Tavernier, T., Taylor, A. M., Terrier, R., Thiersen, J. H. E., Tiziani, D., Tluczykont, M., Tomankova, L., Trichard, C., Tsirou, M., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Vincent, P., Vink, J., Völk, H. J., Wadiasingh, Z., Wagner, S. J., Watson, J., Werner, F., White, R., Wierzcholska, A., Wong, Yu Wun, Yusafzai, A., Zacharias, M., Zanin, R., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S. J., Zmija, A., Zorn, J., Zouari, S., Żywucka, N., Albert, A., Alfaro, R., Alvarez, C., Arteaga-Velázquez, J. C., Arunbabu, K. P., Rojas, D. Avila, Belmont-Moreno, E., BenZvi, S. Y., Brisbois, C., Caballero-Mora, K. S., Capistrán, T., Carramiñana, A., Casanova, S., Cotti, U., Cotzomi, J., de León, S. Coutiño, De la Fuente, E., de León, C., Hernandez, R. Diaz, Díaz-Vélez, J. C., Dingus, B. L., DuVernois, M. A., Durocher, M., Ellsworth, R. W., Engel, K., Espinoza, C., Fan, K. L., Alonso, M. Fernández, Fraija, N., Galván-Gámez, A., Garcia, D., García-González, J. A., Garfias, F., Giacinti, G., González, M. M., Goodman, J. A., Harding, J. P., Hernandez, S., Hona, B., Huang, D., Hueyotl-Zahuantitla, F., Hüntemeyer, P., Iriarte, A., Jardin-Blicq, A., Joshi, V., Kieda, D., Lee, W. H., Vargas, H. León, Linnemann, J. T., Longinotti, A. L., Luis-Raya, G., López-Coto, R., Malone, K., Martinez, O., Martinez-Castellanos, I., Martínez-Castro, J., Matthews, J. A., Miranda-Romagnoli, P., Morales-Soto, J. A., Moreno, E., Mostafá, M., Nellen, L., Newbold, M., Nisa, M. U., Noriega-Papaqui, R., Omodei, N., Peisker, A., Araujo, Y. Pérez, Pérez-Pérez, E. G., Rho, C. D., Rosa-González, D., Ruiz-Velasco, E., Greus, F. Salesa, Sandoval, A., Schneider, M., Schoorlemmer, H., Serna-Franco, J., Smith, A. J., Springer, R. W., Surajbali, P., Tollefson, K., Torres, I., Torres-Escobedo, R., Turner, R., Ureña-Mena, F., Villaseñor, L., Weisgarber, T., Willox, E., and Zhou, H.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The High Altitude Water Cherenkov (HAWC) observatory and the High Energy Stereoscopic System (H.E.S.S.) are two leading instruments in the ground-based very-high-energy gamma-ray domain. HAWC employs the water Cherenkov detection (WCD) technique, while H.E.S.S. is an array of Imaging Atmospheric Cherenkov Telescopes (IACTs). The two facilities therefore differ in multiple aspects, including their observation strategy, the size of their field of view and their angular resolution, leading to different analysis approaches. Until now, it has been unclear if the results of observations by both types of instruments are consistent: several of the recently discovered HAWC sources have been followed up by IACTs, resulting in a confirmed detection only in a minority of cases. With this paper, we go further and try to resolve the tensions between previous results by performing a new analysis of the H.E.S.S. Galactic plane survey data, applying an analysis technique comparable between H.E.S.S. and HAWC. Events above 1 TeV are selected for both datasets, the point spread function of H.E.S.S. is broadened to approach that of HAWC, and a similar background estimation method is used. This is the first detailed comparison of the Galactic plane observed by both instruments. H.E.S.S. can confirm the gamma-ray emission of four HAWC sources among seven previously undetected by IACTs, while the three others have measured fluxes below the sensitivity of the H.E.S.S. dataset. Remaining differences in the overall gamma-ray flux can be explained by the systematic uncertainties. Therefore, we confirm a consistent view of the gamma-ray sky between WCD and IACT techniques.

Published
2021
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164. Long-term spectra of the blazars Mrk 421 and Mrk 501 at TeV energies seen by HAWC

Author

Albert, A., Alfaro, R., Alvarez, C., Camacho, J. R. Angeles, Arteaga-Velázquez, J. C., Arunbabu, K. P., Rojas, D. Avila, Solares, H. A. Ayala, Baghmanyan, V., Belmont-Moreno, Caballero-Mora, K. S., Capistrán, T., Carramiñana, A., Casanova, S., Cotti, U., Cotzomi, J., de León, S. Coutiño, De la Fuente, E., Hernandez, R. Diaz, DuVernois, M. A., Durocher, M., Díaz-Vélez, J. C., Engel, K., Espinoza, C., Fan, K. L., Alonso, M. Fernández, Fraija, N., Garcia, D., García-González, J. A., Garfias, F., González, M. M., Goodman, J. A., Harding, J. P., Hona, B., Huang, D., Hueyotl-Zahuantitla, F., Hüntemeyer, P., Iriarte, A., Joshi, V., Lara, A., Lee, W. H., Lee, J., Vargas, H. León, Longinotti, A. L., Luis-Raya, G., Malone, K., Martinez, O., Martínez-Castro, J., Matthews, J. A., Miranda-Romagnoli, P., Moreno, E., Mostafá, M., Nayerhoda, A., Nellen, L., Newbold, M., Noriega-Papaqui, R., Peisker, A., Araujo, Y. Pérez, Pérez-Pérez, E. G., Rho, C. D., Rosa-González, D., Salazar, H., Greus, F. Salesa, Sandoval, A., Schneider, M., Serna-Franco, J., Smith, A. J., Springer, R. W., Tollefson, K., Torres, I., Torres-Escobedo, R., Ureña-Mena, F., Villaseñor, L., Wang, X., Weisgarber, T., Willox, E., Zhou, H., and de León, C.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The High Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory surveys the very high energy sky in the 300 GeV to $>100$ TeV energy range. HAWC has detected two blazars above $11\sigma$, Markarian 421 (Mrk 421) and Markarian 501 (Mrk 501). The observations are comprised of data taken in the period between June 2015 and July 2018, resulting in a $\sim 1038$ days of exposure. In this work we report the time-averaged spectral analysis for both sources above 0.5 TeV. Taking into account the flux attenuation due to the extragalactic background light (EBL), the intrinsic spectrum of Mrk 421 is described by a power law with an exponential energy cut-off with index $\alpha=2.26\pm(0.12)_{stat}(_{-0.2}^{+0.17})_{sys}$ and energy cut-off $E_c=5.1\pm(1.6)_{stat}(_{-2.5}^{+1.4})_{sys}$ TeV, while the intrinsic spectrum of Mrk 501 is better described by a simple power law with index $\alpha=2.61\pm(0.11)_{stat}(_{-0.07}^{+0.01})_{sys}$. The maximum energies at which the Mrk 421 and Mrk 501 signals are detected are 9 and 12 TeV, respectively. This makes these some of the highest energy detections to date for spectra averaged over years-long timescales. Since the observation of gamma radiation from blazars provides information about the physical processes that take place in their relativistic jets, it is important to study the broad-band spectral energy distribution (SED) of these objects. To this purpose, contemporaneous data in the gamma-ray band to X-ray range, and literature data in the radio to UV range, were used to build time-averaged SEDs that were modeled within a synchrotron self-Compton leptonic scenario., Comment: 16 pages, 5 tables, 9 figures

Published
2021
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167. Projected sensitivity of the LUX-ZEPLIN (LZ) experiment to the two-neutrino and neutrinoless double beta decays of $^{134}$Xe

Author

LUX-ZEPLIN, The, Collaboration, Akerib, D. S., Musalhi, A. K. Al, Alsum, S. K., Amarasinghe, C. S., Ames, A., Anderson, T. J., Angelides, N., Araujo, H. M., Armstrong, J. E., Arthurs, M., Bai, X., Balajthy, J., Balashov, S., Bang, J., Bargemann, J. W., Bauer, D., Baxter, A., Beltrame, P., Bernard, E. P., Bernstein, A., Bhatti, A., Biekert, A., Biesiadzinski, T. P., Birch, H. J., Blockinger, G. M., Bodnia, E., Boxer, B., Brew, C. A. J., Bras, P., Burdin, S., Busenitz, J. K., Buuck, M., Cabrita, R., Carmona-Benitez, M. C., Cascella, M., Chan, C., Chott, N. I., Cole, A., Converse, M. V., Cottle, A., Cox, G., Creaner, O., Cutter, J. E., Dahl, C. E., de Viveiros, L., Dobson, J. E. Y., Druszkiewicz, E., Eriksen, S. R., Fan, A., Fayer, S., Fearon, N. M., Fiorucci, S., Flaecher, H., Fraser, E. D., Fruth, T., Gaitskell, R. J., Genovesi, J., Ghag, C., Gibson, E., Gokhale, S., van der Grinten, M. G. D., Gwilliam, C. B., Hall, C. R., Haselschwardt, S. J., Hertel, S. A., Horn, M., Huang, D. Q., Ignarra, C. M., Jahangir, O., James, R. S., Ji, W., Johnson, J., Kaboth, A. C., Kamaha, A. C., Kamdin, K., Kazkaz, K., Khaitan, D., Khazov, A., Khurana, I., Kodroff, D., Korley, L., Korolkova, E. V., Kraus, H., Kravitz, S., Kreczko, L., Krikler, B., Kudryavtsev, V. A., Leason, E. A., Lee, J., Leonard, D. S., Lesko, K. T., Levy, C., Liao, J., Lin, J., Lindote, A., Linehan, R., Lippincott, W. H., Liu, X., Lopes, M. I., Asamar, E. Lopez, Paredes, B. Lopez, Lorenzon, W., Luitz, S., Majewski, P. A., Manalaysay, A., Manenti, L., Mannino, R. L., Marangou, N., McCarthy, M. E., McKinsey, D. N., McLaughlin, J., Miller, E. H., Mizrachi, E., Monte, A., Monzani, M. E., Morad, J. A., Mendoza, J. D. Morales, Morrison, E., Mount, B. J., Murphy, A. St. J., Naim, D., Naylor, A., Nedlik, C., Nelson, H. N., Neves, F., Nikoleyczik, J. A., Nilima, A., Olcina, I., Oliver-Mallory, K. C., Pal, S., Palladino, K. J., Palmer, J., Patton, S., Parveen, N., Pease, E. K., Penning, B., Pereira, G., Piepke, A., Qie, Y., Reichenbacher, J., Rhyne, C. A., Richards, A., Riffard, Q., Rischbieter, G. R. C., Rosero, R., Rossiter, P., Santone, D., Sazzad, A. B. M. R., Schnee, R. W., Scovell, P. R., Shaw, S., Shutt, T. A., Silk, J. J., Silva, C., Smith, R., Solmaz, M., Solovov, V. N., Sorensen, P., Soria, J., Stancu, I., Stevens, A., Stifter, K., Suerfu, B., Sumner, T. J., Swanson, N., Szydagis, M., Taylor, W. C., Taylor, R., Temples, D. J., Terman, P. A., Tiedt, D. R., Timalsina, M., To, W. H., Tovey, D. R., Tripathi, M., Tronstad, D. R., Turner, W., Utku, U., Vaitkus, A., Wang, B., Wang, J. J., Wang, W., Watson, J. R., Webb, R. C., White, R. G., Whitis, T. J., Williams, M., Wolfs, F. L. H., Woodward, D., Wright, C. J., Xiang, X., Xu, J., Yeh, M., and Zarzhitsky, P.

Subjects
Physics - Instrumentation and Detectors, Nuclear Experiment
Abstract

The projected sensitivity of the LUX-ZEPLIN (LZ) experiment to two-neutrino and neutrinoless double beta decay of $^{134}$Xe is presented. LZ is a 10-tonne xenon time projection chamber optimized for the detection of dark matter particles, that is expected to start operating in 2021 at Sanford Underground Research Facility, USA. Its large mass of natural xenon provides an exceptional opportunity to search for the double beta decay of $^{134}$Xe, for which xenon detectors enriched in $^{136}$Xe are less effective. For the two-neutrino decay mode, LZ is predicted to exclude values of the half-life up to 1.7$\times$10$^{24}$ years at 90% confidence level (CL), and has a three-sigma observation potential of 8.7$\times$10$^{23}$ years, approaching the predictions of nuclear models. For the neutrinoless decay mode LZ, is projected to exclude values of the half-life up to 7.3$\times$10$^{24}$ years at 90% CL., Comment: Version accepted for publication in Phys. Rev. C

Published
2021
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168. Calibration of the Air Shower Energy Scale of the Water and Air Cherenkov Techniques in the LHAASO experiment

Author

Aharonian, F., An, Q., Axikegu, Bai, L. X., Bai, Y. X., Bao, Y. W., Bastieri, D., Bi, X. J., Bi, Y. J., Cai, H., Cai, J. T., Cao, Z. Cao Z., Chang, J., Chang, J. F., Chang, X. C., Chen, B. M., Chen, J., Chen, L., Chen, M. J., Chen, M. L., Chen, Q. H., Chen, S. H., Chen, S. Z., Chen, T. L., Chen, X. L., Chen, Y., Cheng, N., Cheng, Y. D., Cui, S. W., Cui, X. H., Cui, Y. D., Dai, B. Z., Dai, H. L., Dai, Z. G., Danzengluobu, della Volpe, D., Piazzoli, B. DEttorre, Dong, X. J., Fan, J. H., Fan, Y. Z., Fan, Z. X., Fang, J., Fang, K., Feng, C. F., Feng, L., Feng, S. H., Feng, Y. L., Gao, B., Gao, C. D., Gao, Q., Gao, W., Ge, M. M., Geng, L. S., Gong, G. H., Gou, Q. B., Gu, M. H., Guo, J. G., Guo, X. L., Guo, Y. Q., Guo, Y. Y., Han, Y. A., He, H. H., He, H. N., He, J. C., He, S. L., He, X. B., He, Y., Heller, M., Hor, Y. K., Hou, C., Hou, X., Hu, H. B., Hu, S., Hu, S. C., Hu, X. J., Huang, D. H., Huang, Q. L., Huang, W. H., Huang, X. T., Huang, Z. C., Ji, F., Ji, X. L., Jia, H. Y., Jiang, K., Jiang, Z. J., Jin, C., Kuleshov, D., Levochkin, K., Li, B. B., Li, C., Li, F., Li, H. B., Li, H. C., Li, H. Y., Li, J., Li, K., Li, W. L., Li, X., Li, X. R., Li, Y., Li, Y. Z., Li, Z., Liang, E. W., Liang, Y. F., Lin, S. J., Liu, B., Liu, C., Liu, D., Liu, H., Liu, H. D., Liu, J., Liu, J. L., Liu, J. S., Liu, J. Y., Liu, M. Y., Liu, R. Y., Liu, S. M., Liu, W., Liu, Y. N., Liu, Z. X., Long, W. J., Lu, R., Lv, H. K., Ma, B. Q., Ma, L. L., Ma, X. H., Mao, J. R., Masood, A., Mitthumsiri, W., Montaruli, T., Nan, Y. C., Pang, B. Y., Pattarakijwanich, P., Pei, Z. Y., Qi, M. Y., Ruffolo, D., Rulev, V., Saiz, A., Shao, L., Shchegolev, O., Sheng, X. D., Shi, J. R., Song, H. C., Stenkin, Yu. V., Stepanov, V., Sun, Q. N., Sun, X. N., Sun, Z. B., Tam, P. H. T., Tang, Z. B., Tian, W. W., Wang, B. D., Wang, C., Wang, H., Wang, H. G., Wang, J. C., Wang, J. S., Wang, L. P., Wang, L. Y., Wang, R. N., Wang, W., Wang, X. G., Wang, X. J., Wang, X. Y., Wang, Y. D., Wang, Y. J., Wang, Y. P., Wang, Z., Wang, Z. H., Wang, Z. X., Wei, D. M., Wei, J. J., Wei, Y. J., Wen, T., Wu, C. Y., Wu, H. R., Wu, S., Wu, X., Wu, X. F., Xi, S. Q., Xia, J., Xia, J. J., Xiang, G. M., Xiao, G., Xiao, H. B., Xin, G. G., Xin, Y. L., Xing, Y., Xu, D. L., Xu, R. X., Xue, L., Yan, D. H., Yang, C. W., Yang, F. F., Yang, J. Y., Yang, L. L., Yang, M. J., Yang, R. Z., Yang, S. B., Yao, Y. H., Yao, Z. G., Ye, Y. M., Yin, L. Q., Yin, N., You, X. H., You, Z. Y., Yu, Y. H., Yuan, Q., Zeng, H. D., Zeng, T. X., Zeng, W., Zeng, Z. K., Zha, M., Zhai, X. X., Zhang, B. B., Zhang, H. M., Zhang, H. Y., Zhang, J. L., Zhang, J. W., Zhang, L., Zhang, L. X., Zhang, P. F., Zhang, P. P., Zhang, R., Zhang, S. R., Zhang, S. S., Zhang, X., Zhang, X. P., Zhang, Y., Zhang, Y. F., Zhang, Y. L., Zhao, B., Zhao, J., Zhao, L., Zhao, L. Z., Zhao, S. P., Zheng, F., Zheng, Y., Zhou, B., Zhou, H., Zhou, J. N., Zhou, P., Zhou, R., Zhou, X. X., Zhu, C. G., Zhu, F. R., Zhu, H., Zhu, K. J., and Zuo, X.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract

The Wide Field-of-View Cherenkov Telescope Array (WFCTA) and the Water Cherenkov Detector Arrays (WCDA) of LHAASO are designed to work in combination for measuring the energy spectra of various cosmic ray species over a very wide energy range from a few TeV to 10 PeV. The energy calibration of WCDA can be achieved with a proven technique of measuring the westward shift of the Moon shadow of galactic cosmic rays due to the geomagnetic field. This deflection angle $\Delta$ is inversely proportional to the energy of the cosmic rays. The precise measurements of the shifts by WCDA allows us to calibrate its energy scale for energies as high as 35 TeV. The energy scale measured by WCDA can be used to cross calibrate the energy reconstructed by WFCTA, which spans the whole energy range up to 10 PeV. In this work, we will demonstrate the feasibility of the method using the data collected from April 2019 to January 2020 by the WFCTA array and WCDA-1 detector, the first of the three water Cherenkov ponds, already commissioned at LHAASO site.

Published
2021
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169. HAWC observations of the acceleration of very-high-energy cosmic rays in the Cygnus Cocoon

Author

Abeysekara, A. U., Albert, A., Alfaro, R., Alvarez, C., Camacho, J. R. Angeles, Arteaga-Velazquez, J. C., Arunbabu, K. P., Rojas, D. Avila, Solares, H. A. Ayala, Baghmanyan, V., Belmont-Moreno, E., BenZvi, S. Y., Blandford, R., Brisbois, C., Caballero-Mora, K. S., Capistran, T., Carraminana, A., Casanova, S., Cotti, U., de Leon, S. Coutino, De la Fuente, E., Hernandez, R. Diaz, Dingus, B. L., DuVernois, M. A., Durocher, M., Diaz-Velez, J. C., Ellsworth, R. W., Engel, K., Espinoza, C., Fan, K. L., Fang, K., Fleischhack, H., Fraija, N., Galvan-Gamez, A., Garcia, D., Garcıa-Gonzalez, J. A., Garfias, F., Giacinti, G., Gonzalez, M. M., Goodman, J. A., Harding, J. P., Hernandez, S., Hinton, J., Hona, B., Huang, D., Hueyotl-Zahuantitla, F., Huntemeyer, P., Iriarte, A., Jardin-Blicq, A., Joshi, V., Kieda, D., Lara, A., Lee, W. H., Vargas, H. Leon, Linnemann, J. T., Longinotti, A. L., Luis-Raya, G., Lundeen, J., Malone, K., Martinez, O., Martinez-Castellanos, I., Martinez-Castro, J., Matthews, J. A., Miranda-Romagnoli, P., Soto, J. A. Morales, Moreno, E., Mostafa, M., Nayerhoda, A., Nellen, L., Newbold, M., Nisa, M. U., Noriega-Papaqui, R., Olivera-Nieto, L., Omodei, N., Peisker, A., Araujo, Y. Perez, Perez-Perez, E. G., Ren, Z., Rho, C. D., Rosa-Gonzalez, D., Ruiz-Velasco, E., Salazar, H., Greus, F. Salesa, Sandova, A., Schneider, M., Schoorlemmer, H., Serna, F., Smith, A. J., Springer, R. W., Surajbali, P., Tollefson, K., Torres, I., Torres-Escobedo, R., Urena-Mena, F., Weisgarber, T., Werner, F., Willox, E., Zepeda, A., Zhou, H., on, C. De Le, and Alvarez, J. D.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Cosmic rays with energies up to a few PeV are known to be accelerated within the Milky Way. Traditionally, it has been presumed that supernova remnants were the main source of very-high-energy cosmic rays but theoretically it is difficult to get protons to PeV energies and observationally there simply is no evidence to support the remnants as sources of hadrons with energies above a few tens of TeV. One possible source of protons with those energies is the Galactic Center region. Here we report observations of 1-100 TeV gamma rays coming from the 'Cygnus Cocoon', which is a superbubble surrounding a region of OB2 massive star formation. These gamma rays are likely produced by 10-1000 TeV freshly accelerated CRs originating from the enclosed star forming region Cygnus OB2. Hitherto it was not known that such regions could accelerate particles to these energies. The measured flux is likely originated by hadronic interactions. The spectral shape and the emission profile of the Cocoon changes from GeV to TeV energies, which reveals the transport of cosmic particles and historical activity in the superbubble.

Published
2021
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170. Projected sensitivities of the LUX-ZEPLIN (LZ) experiment to new physics via low-energy electron recoils

Author

The LZ Collaboration, Akerib, D. S., Musalhi, A. K. Al, Alsum, S. K., Amarasinghe, C. S., Ames, A., Anderson, T. J., Angelides, N., Araújo, H. M., Armstrong, J. E., Arthurs, M., Bai, X., Balajthy, J., Balashov, S., Bang, J., Bargemann, J. W., Bauer, D., Baxter, A., Beltrame, P., Bernard, E. P., Bernstein, A., Bhatti, A., Biekert, A., Biesiadzinski, T. P., Birch, H. J., Blockinger, G. M., Bodnia, E., Boxer, B., Brew, C. A. J., Brás, P., Burdin, S., Busenitz, J. K., Buuck, M., Cabrita, R., Carmona-Benitez, M. C., Cascella, M., Chan, C., Chott, N. I., Cole, A., Converse, M. V., Cottle, A., Cox, G., Creaner, O., Cutter, J. E., Dahl, C. E., de Viveiros, L., Dobson, J. E. Y., Druszkiewicz, E., Eriksen, S. R., Fan, A., Fayer, S., Fearon, N. M., Fiorucci, S., Flaecher, H., Fraser, E. D., Fruth, T., Gaitskell, R. J., Genovesi, J., Ghag, C., Gibson, E., Gokhale, S., van der Grinten, M. G. D., Gwilliam, C. B., Hall, C. R., Hardy, C. A., Haselschwardt, S. J., Hertel, S. A., Horn, M., Huang, D. Q., Ignarra, C. M., Jahangir, O., James, R. S., Ji, W., Johnson, J., Kaboth, A. C., Kamaha, A. C., Kamdin, K., Kazkaz, K., Khaitan, D., Khazov, A., Khurana, I., Kodroff, D., Korley, L., Korolkova, E. V., Kraus, H., Kravitz, S., Kreczko, L., Krikler, B., Kudryavtsev, V. A., Leason, E. A., Lee, J., Leonard, D. S., Lesko, K. T., Levy, C., Li, J., Liao, J., Lindote, A., Linehan, R., Lippincott, W. H., Liu, X., Lopes, M. I., Asamar, E. Lopez, Paredes, B. López, Lorenzon, W., Luitz, S., Majewski, P. A., Manalaysay, A., Manenti, L., Mannino, R. L., Marangou, N., McCarthy, M. E., McKinsey, D. N., McLaughlin, J., Miller, E. H., Mizrachi, E., Monte, A., Monzani, M. E., Morad, J. A., Mendoza, J. D. Morales, Morrison, E., Mount, B. J., Murphy, A. St. J., Naim, D., Naylor, A., Nedlik, C., Nelson, H. N., Neves, F., Nikoleyczik, J. A., Nilima, A., Nguyen, A., Olcina, I., Oliver-Mallory, K. C., Pal, S., Palladino, K. J., Palmer, J., Patton, S., Parveen, N., Pease, E. K., Penning, B., Pereira, G., Piepke, A., Qie, Y., Reichenbacher, J., Rhyne, C. A., Richards, A., Riffard, Q., Rischbieter, G. R. C., Rosero, R., Rossiter, P., Santone, D., Sazzad, A. B. M. R., Schnee, R. W., Scovell, P. R., Shaw, S., Shutt, T. A., Silk, J. J., Silva, C., Smith, R., Solmaz, M., Solovov, V. N., Sorensen, P., Soria, J., Stancu, I., Stevens, A., Stifter, K., Suerfu, B., Sumner, T. J., Swanson, N., Szydagis, M., Taylor, W. C., Taylor, R., Temples, D. J., Terman, P. A., Tiedt, D. R., Timalsina, M., To, W. H., Tovey, D. R., Tripathi, M., Tronstad, D. R., Turner, W., Utku, U., Vaitkus, A., Wang, B., Wang, J. J., Wang, W., Watson, J. R., Webb, R. C., White, R. G., Whitis, T. J., Williams, M., Wolfs, F. L. H., Woodward, D., Wright, C. J., Xiang, X., Xu, J., Yeh, M., and Zarzhitsky, P.

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

LUX-ZEPLIN (LZ) is a dark matter detector expected to obtain world-leading sensitivity to weakly interacting massive particles (WIMPs) interacting via nuclear recoils with a ~7-tonne xenon target mass. This manuscript presents sensitivity projections to several low-energy signals of the complementary electron recoil signal type: 1) an effective neutrino magnetic moment and 2) an effective neutrino millicharge, both for pp-chain solar neutrinos, 3) an axion flux generated by the Sun, 4) axion-like particles forming the galactic dark matter, 5) hidden photons, 6) mirror dark matter, and 7) leptophilic dark matter. World-leading sensitivities are expected in each case, a result of the large 5.6t 1000d exposure and low expected rate of electron recoil backgrounds in the $<$100keV energy regime. A consistent signal generation, background model and profile-likelihood analysis framework is used throughout., Comment: v2 updates exclusion sensitivities from single-sided to two-sided

Published
2021
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171. Constraints on Effective Field Theory Couplings Using 311.2 days of LUX Data

Author

Akerib, D. S., Alsum, S., Araújo, H. M., Bai, X., Balajthy, J., Bang, J., Baxter, A., Bernard, E. P., Bernstein, A., Biesiadzinski, T. P., Boulton, E. M., Boxer, B., Brás, P., Burdin, S., Byram, D., Carmona-Benitez, M. C., Chan, C., Cutter, J. E., de Viveiros, L., Druszkiewicz, E., Fan, A., Fiorucci, S., Gaitskell, R. J., Ghag, C., Gilchriese, M. G. D., Gwilliam, C., Hall, C. R., Haselschwardt, S. J., Hertel, S. A., Hogan, D. P., Horn, M., Huang, D. Q., Ignarra, C. M., Jacobsen, R. G., Jahangir, O., Ji, W., Kamdin, K., Kazkaz, K., Khaitan, D., Korolkova, E. V., Kravitz, S., Kudryavtsev, V. A., Leason, E., Lenardo, B. G., Lesko, K. T., Liao, J., Lin, J., Lindote, A., Lopes, M. I., Manalaysay, A., Mannino, R. L., Marangou, N., McKinsey, D. N., Mei, D. -M., Morad, J. A., Murphy, A. St. J., Naylor, A., Nehrkorn, C., Nelson, H. N., Neves, F., Nilima, A., Oliver-Mallory, K. C., Palladino, K. J., Rhyne, C., Riffard, Q., Rischbieter, G. R. C., Rossiter, P., Shaw, S., Shutt, T. A., Silva, C., Solmaz, M., Solovov, V. N., Sorensen, P., Sumner, T. J., Swanson, N., Szydagis, M., Taylor, D. J., Taylor, R., Taylor, W. C., Tennyson, B. P., Terman, P. A., Tiedt, D. R., To, W. H., Tvrznikova, L., Utku, U., Vacheret, A., Vaitkus, A., Velan, V., Webb, R. C., White, J. T., Whitis, T. J., Witherell, M. S., Wolfs, F. L. H., Woodward, D., Xiang, X., Xu, J., and Zhang, C.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We report here the results of an Effective Field Theory (EFT) WIMP search analysis using LUX data. We build upon previous LUX analyses by extending the search window to include nuclear recoil energies up to $\sim$180 keV$_{nr}$, requiring a reassessment of data quality cuts and background models. In order to use a binned Profile Likelihood statistical framework, the development of new analysis techniques to account for higher-energy backgrounds was required. With a 3.14$\times10^4$ kg$\cdot$day exposure using data collected between 2014 and 2016, we set 90\% C.L. exclusion limits on non-relativistic EFT WIMP couplings to neutrons and protons, providing the most stringent constraints on a significant fraction of the possible EFT WIMP interactions. Additionally, we report world-leading exclusion limits on inelastic EFT WIMP-nucleon recoils., Comment: 19 Pages, 10 Figures, 4 Table

Published
2021
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172. Testing new physics models with global comparisons to collider measurements: the Contur toolkit

Author

Buckley, A., Butterworth, J. M., Corpe, L., Habedank, M., Huang, D., Yallup, D., Altakach, M., Bassman, G., Lagwankar, I., Rocamonde, J., Saunders, H., Waugh, B., and Zilgalvis, G.

Subjects
High Energy Physics - Phenomenology
Abstract

Measurements at particle collider experiments, even if primarily aimed at understanding Standard Model processes, can have a high degree of model independence, and implicitly contain information about potential contributions from physics beyond the Standard Model. The Contur package allows users to benefit from the hundreds of measurements preserved in the Rivet library to test new models against the bank of LHC measurements to date. This method has proven to be very effective in several recent publications from the Contur team, but ultimately, for this approach to be successful, the authors believe that the Contur tool needs to be accessible to the wider high energy physics community. As such, this manual accompanies the first user-facing version: Contur v2. It describes the design choices that have been made, as well as detailing pitfalls and common issues to avoid. The authors hope that with the help of this documentation, external groups will be able to run their own Contur studies, for example when proposing a new model, or pitching a new search.

Published
2021
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173. Magnetoresistive Sensor Detectivity: A Comparative Analysis

Author

Davies, J. E., Watts, J. D., Novotny, J., Huang, D., and Eames, P. G.

Subjects
Condensed Matter - Materials Science
Abstract

We report on the noise performance characteristics of magnetic sensors using both magnetic tunnel junction (MTJ) and giant magnetoresistance (GMR) elements. Each sensor studied has a notably different noise and detectivity. Of the sensors we measured, those based on GMR multilayers have the lowest noise and detectivity. However, the GMR sensor also has a significantly smaller linear range. To make a direct comparison between sensors we scale the linear operating ranges of each sensor to be the same. This is the phenomenological equivalent of modifying the flux concentration. Upon scaling the low frequency detectivity of the TMR sensors becomes essentially equal to that of the GMR sensor. Using the scaling approach we are able to place the detectivity in the context of other key parameters, namely size and power consumption. Lastly, we use this technique to examine the upper limit for magnetoresistive sensor performance based on a notional MTJ sensor using present record setting TMR values., Comment: Accepted to Applied Physics Letters, 6 pages, 7 figures

Published
2021
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174. Enhancing the sensitivity of the LUX-ZEPLIN (LZ) dark matter experiment to low energy signals

Author

Akerib, D. S., Musalhi, A. K. Al, Alsum, S. K., Amarasinghe, C. S., Ames, A., Anderson, T. J., Angelides, N., Araújo, H. M., Armstrong, J. E., Arthurs, M., Bai, X., Balajthy, J., Balashov, S., Bang, J., Bargemann, J. W., Bauer, D., Baxter, A., Beltrame, P., Bernard, E. P., Bernstein, A., Bhatti, A., Biekert, A., Biesiadzinski, T. P., Birch, H. J., Blockinger, G. M., Boxer, B., Brew, C. A. J., Brás, P., Burdin, S., Busenitz, J. K., Buuck, M., Cabrita, R., Carmona-Benitez, M. C., Cascella, M., Chan, C., Chott, N. I., Cole, A., Converse, M. V., Cottle, A., Cox, G., Cutter, J. E., Dahl, C. E., de Viveiros, L., Dobson, J. E. Y., Druszkiewicz, E., Eriksen, S. R., Fan, A., Fayer, S., Fearon, N. M., Fiorucci, S., Flaecher, H., Fraser, E. D., Fruth, T., Gaitskell, R. J., Genovesi, J., Ghag, C., Gibson, E., Gokhale, S., van der Grinten, M. G. D., Gwilliam, C. B., Hall, C. R., Haselschwardt, S. J., Hertel, S. A., Horn, M., Huang, D. Q., Ignarra, C. M., Jahangir, O., James, R. S., Ji, W., Johnson, J., Kaboth, A. C., Kamaha, A. C., Kamdin, K., Kazkaz, K., Khaitan, D., Khazov, A., Khurana, I., Kodroff, D., Korley, L., Korolkova, E. V., Kraus, H., Kravitz, S., Kreczko, L., Krikler, B., Kudryavtsev, V. A., Leason, E. A., Lesko, K. T., Levy, C., Li, J., Liao, J., Lin, J., Lindote, A., Linehan, R., Lippincott, W. H., Liu, X., Lopes, M. I., Asamar, E. Lopez, Paredes, B. López, Lorenzon, W., Luitz, S., Majewski, P. A., Manalaysay, A., Manenti, L., Mannino, R. L., Marangou, N., McCarthy, M. E., McKinsey, D. N., McLaughlin, J., Miller, E. H., Mizrachi, E., Monte, A., Monzani, M. E., Morad, J. A., Mendoza, J. D. Morales, Morrison, E., Mount, B. J., Murphy, A. St. J., Naim, D., Naylor, A., Nedlik, C., Nelson, H. N., Neves, F., Nikoleyczik, J. A., Olcina, I., Oliver-Mallory, K. C., Pal, S., Palladino, K. J., Palmer, J., Parveen, N., Pease, E. K., Penning, B., Pereira, G., Piepke, A., Qie, Y., Reichenbacher, J., Rhyne, C. A., Richards, A., Riffard, Q., Rischbieter, G. R. C., Rosero, R., Rossiter, P., Santone, D., Sazzad, A. B. M. R., Schnee, R. W., Scovell, P. R., Shaw, S., Shutt, T. A., Silk, J. J., Silva, C., Smith, R., Solmaz, M., Solovov, V. N., Sorensen, P., Stancu, I., Stevens, A., Stifter, K., Suerfu, B., Sumner, T. J., Swanson, N., Szydagis, M., Taylor, W. C., Taylor, R., Temples, D. J., Terman, P. A., Tiedt, D. R., Timalsina, M., To, W. H., Tripathi, M., Tronstad, D. R., Turner, W., Utku, U., Vaitkus, A., Wang, B., Wang, J. J., Wang, W., Watson, J. R., Webb, R. C., White, R. G., Whitis, T. J., Williams, M., Wolfs, F. L. H., Woodward, D., Wright, C. J., Xiang, X., Xu, J., Yeh, M., and Zarzhitsky, P.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Physics - Instrumentation and Detectors
Abstract

Two-phase xenon detectors, such as that at the core of the forthcoming LZ dark matter experiment, use photomultiplier tubes to sense the primary (S1) and secondary (S2) scintillation signals resulting from particle interactions in their liquid xenon target. This paper describes a simulation study exploring two techniques to lower the energy threshold of LZ to gain sensitivity to low-mass dark matter and astrophysical neutrinos, which will be applicable to other liquid xenon detectors. The energy threshold is determined by the number of detected S1 photons; typically, these must be recorded in three or more photomultiplier channels to avoid dark count coincidences that mimic real signals. To lower this threshold: a) we take advantage of the double photoelectron emission effect, whereby a single vacuum ultraviolet photon has a $\sim20\%$ probability of ejecting two photoelectrons from a photomultiplier tube photocathode; and b) we drop the requirement of an S1 signal altogether, and use only the ionization signal, which can be detected more efficiently. For both techniques we develop signal and background models for the nominal exposure, and explore accompanying systematic effects, including the dependence on the free electron lifetime in the liquid xenon. When incorporating double photoelectron signals, we predict a factor of $\sim 4$ sensitivity improvement to the dark matter-nucleon scattering cross-section at $2.5$ GeV/c$^2$, and a factor of $\sim1.6$ increase in the solar $^8$B neutrino detection rate. Dropping the S1 requirement may allow sensitivity gains of two orders of magnitude in both cases. Finally, we apply these techniques to even lower masses by taking into account the atomic Migdal effect; this could lower the dark matter particle mass threshold to $80$ MeV/c$^2$., Comment: 14 pages, 6 figures

Published
2021

175. HAWC Search for High-Mass Microquasars

Author

HAWC Collaboration, Albert, A., Alfaro, R., Alvarez, C., Camacho, J. R. Angeles, Arteaga-Velazquez, J. C., Arunbabu, K. P., Rojas, D. Avila, Solares, H. A. Ayala, Baghmanyan, V., Belmont-Moreno, E., BenZvi, S. Y., Brisbois, C., Caballero-Mora, K. S., Capistran, T., Carraminana, A., Casanova, S., Cotti, U., Cotzomi, J., De la Fuente, E., de Leon, C., Hernandez, R. Diaz, Diaz-Velez, J. C., Dingus, B. L., Durocher, M., DuVernois, M. A., Ellsworth, R. W., Espinoza, C., Fan, K. L., Fang, K., Fraija, N., Galvan-Gamez, A., Garcia-Gonzalez, J. A., Garfias, F., Gonzalez, M. M., Goodman, J. A., Harding, J. P., Hernandez, S., Hona, B., Huang, D., Hueyotl-Zahuantitla, F., Huntemeyer, P., Iriarte, A., Jardin-Blicq, A., Joshi, V., Kieda, D., Lara, A., Lee, J., Lee, W. H., Vargas, H. Leon, Linnemann, J. T., Longinotti, A. L., Luis-Raya, G., Lundeen, J., Malone, K., Martinez, O., Martinez-Castro, J., Matthews, J. A., Miranda-Romagnoli, P., Morales-Soto, J. A., Moreno, E., Mostafa, M., Nayerhoda, A., Nellen, L., Newbold, M., Nisa, M. U., Noriega-Papaqui, R., Olivera-Nieto, L., Omodei, N., Peisker, A., Araujo, Y. Perez, Rho, C. D., Roh, Y. J., Rosa-Gonzalez, D., Greus, F. Salesa, Sandoval, A., Schneider, M., Serna-Franco, J., Smith, A. J., Springer, R. W., Tollefson, K., Torres, I., Torres-Escobedo, R., Turner, R., Urena-Mena, F., Villasenor, L., Watson, I. J., Weisgarber, T., Willox, E., and Zhou, H.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Microquasars with high-mass companion stars are promising very-high-energy (VHE; 0.1-100 TeV) gamma-ray emitters, but their behaviors above 10 TeV are poorly known. Using the High Altitude Water Cherenkov (HAWC) observatory, we search for excess gamma-ray emission coincident with the positions of known high-mass microquasars (HMMQs). No significant emission is observed for LS 5039, Cygnus X-1, Cygnus X-3, and SS 433 with 1,523 days of HAWC data. We set the most stringent limit above 10 TeV obtained to date on each individual source. Under the assumption that HMMQs produce gamma rays via a common mechanism, we have performed source-stacking searches, considering two different scenarios: I) gamma-ray luminosity is a fraction $\epsilon_\gamma$ of the microquasar jet luminosity, and II) very-high-energy gamma rays are produced by relativistic electrons up-scattering the radiation field of the companion star in a magnetic field $B$. We obtain $\epsilon_\gamma < 5.4\times 10^{-6}$ for scenario I, which tightly constrains models that suggest observable high-energy neutrino emission by HMMQs. In the case of scenario II, the non-detection of VHE gamma rays yields a strong magnetic field, which challenges synchrotron radiation as the dominant mechanism of the microquasar emission between 10 keV and 10 MeV., Comment: Accepted for publication in ApJL

Published
2021
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176. Probing the Sea of Cosmic Rays by Measuring Gamma-Ray Emission from Passive Giant Molecular Clouds with HAWC

Author

Albert, A., Alfaro, R., Alvarez, C., Camacho, J. R. Angeles, Arteaga-Velázquez, J. C., Arunbabu, K. P., Rojas, D. Avila, Solares, H. A. Ayala, Baghmanyan, V., Belmont-Moreno, E., BenZvi, S. Y., Brisbois, C., Caballero-Mora, K. S., Capistrán, T., Carramiñana, A., Casanova, S., Cotti, U., Cotzomi, J., de León, S. Coutiño, De la Fuente, E., Hernandez, R. Diaz, Dingus, B. L., DuVernois, M. A., Durocher, M., Díaz-Vélez, J. C., Ellsworth, R. W., Engel, K., Espinoza, C., Fan, K. L., Alonso, M. Fernández, Fraija, N., Galván-Gámez, A., Garcia, D., González, J. A. García-González F. Garfias M. M., Goodman, J. A., Harding, J. P., Hernandez, S., Hona, B., Huang, D., Hueyotl-Zahuantitla, F., Hüntemeyer, P., Iriarte, A., Joshi, V., Kieda, D., Lara, A., Lee, W. H., Lee, J., Vargas, H. León, Linnemann, J. T., Longinotti, A. L., Luis-Raya, G., Lundeen, J., Malone, K., Martinez, O., Martínez-Castro, J., Matthews, J. A., Miranda-Romagnoli, P., Morales-Soto, J. A., Moreno, E., Mostafá, M., Nayerhoda, A., Nellen, L., Newbold, M., Nisa, M. U., Noriega-Papaqui, R., Omodei, N., Peisker, A., Araujo, Y. Pérez, Pérez-Pérez, E. G., Rho, C. D., Rosa-González, D., Ruiz-Velasco, E., Greus, F. Salesa, Sandoval, A., Schneider, M., Serna-Franco, J., Smith, A. J., Springer, R. W., Surajbali, P., Tanner, M., Tollefson, K., Torres, I., Torres-Escobedo, R., Turner, R., Ureña-Mena, F., Villaseñor, L., Weisgarber, T., Willox, E., Zhou, H., and de León, C.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The study of high-energy gamma rays from passive Giant Molecular Clouds (GMCs) in our Galaxy is an indirect way to characterize and probe the paradigm of the "sea" of cosmic rays in distant parts of the Galaxy. By using data from the High Altitude Water Cherenkov (HAWC) observatory, we measure the gamma-ray flux above 1 TeV of a set of these clouds to test the paradigm. We selected high-galactic latitude clouds that are in HAWC's field-of-view and which are within 1~kpc distance from the Sun. We find no significant excess emission in the cloud regions, nor when we perform a stacked log-likelihood analysis of GMCs. Using a Bayesian approach, we calculate 95\% credible intervals upper limits of the gamma-ray flux and estimate limits on the cosmic-ray energy density of these regions. These are the first limits to constrain gamma-ray emission in the multi-TeV energy range ($>$1 TeV) using passive high-galactic latitude GMCs. Assuming that the main gamma-ray production mechanism is due to proton-proton interaction, the upper limits are consistent with a cosmic-ray flux and energy density similar to that measured at Earth., Comment: 6 figures, 6 tables

Published
2021
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177. Evidence that Ultra-High-Energy Gamma Rays are a Universal Feature Near Powerful Pulsars

Author

HAWC Collaboration, Albert, A., Alfaro, R., Alvarez, C., Álvarez, J. D., Camacho, J. R. Angeles, Arteaga-Velázquez, J. C., Arunbabu, K. P., Rojas, D. Avila, Solares, H. A. Ayala, Baghmanyan, V., Belmont-Moreno, E., BenZvi, S. Y., Brisbois, C., Caballero-Mora, K. S., Capistrán, T., Carramiñana, A., Casanova, S., Cotti, U., Cotzomi, J., de León, S. Coutiño, De la Fuente, E., de León, C., Hernandez, R. Diaz, Dingus, B. L., DuVernois, M. A., Durocher, M., Díaz-Vélez, J. C., Ellsworth, R. W., Engel, K., Espinoza, C., Fan, K. L., Alonso, M. Fernández, Fraija, N., Galván-Gámez, A., García-González, J. A., Garfias, F., Giacinti, G., González, M. M., Goodman, J. A., Harding, J. P., Hernandez, S., Hona, B., Huang, D., Hueyotl-Zahuantitla, F., Hüntemeyer, P., Iriarte, A., Jardin-Blicq, A., Joshi, V., Kieda, D., Lara, A., Lee, W. H., Lee, J., Vargas, H. León, Linnemann, J. T., Longinotti, A. L., Luis-Raya, G., Lundeen, J., Malone, K., Marandon, V., Martinez, O., Martínez-Castro, J., Matthews, J. A., Miranda-Romagnoli, P., Morales-Soto, J. A., Moreno, E., Mostafá, M., Nayerhoda, A., Nellen, L., Newbold, M., Nisa, M. U., Noriega-Papaqui, R., Olivera-Nieto, L., Omodei, N., Peisker, A., Araujo, Y. Pérez, Pérez-Pérez, E. G., Rho, C. D., Roh, Y. J., Rosa-González, D., Ruiz-Velasco, E., Salazar, H., Greus, F. Salesa, Sandoval, A., Schneider, M., Schoorlemmer, H., Serna-Franco, J., Smith, A. J., Springer, R. W., Surajbali, P., Tanner, M., Tollefson, K., Torres, I., Torres-Escobedo, R., Turner, R., Ureña-Mena, F., Villaseñor, L., Weisgarber, T., Willox, E., and Zhou, H.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The highest-energy known gamma-ray sources are all located within 0.5 degrees of extremely powerful pulsars. This raises the question of whether ultra-high-energy (UHE; $>$ 56 TeV) gamma-ray emission is a universal feature expected near pulsars with a high spin-down power. Using four years of data from the High Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory, we present a joint-likelihood analysis of ten extremely powerful pulsars to search for UHE gamma-ray emission correlated with these locations. We report a significant detection ($>$ 3$\sigma$), indicating that UHE gamma-ray emission is a generic feature of powerful pulsars. We discuss the emission mechanisms of the gamma rays and the implications of this result. The individual environment that each pulsar is found in appears to play a role in the amount of emission., Comment: accepted by ApJL

Published
2021
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178. Planar Hall effect with sixfold oscillations in a Dirac antiperovskite

Author

Huang, D., Nakamura, H., and Takagi, H.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

The planar Hall effect (PHE), wherein a rotating magnetic field in the plane of a sample induces oscillating transverse voltage, has recently garnered attention in a wide range of topological metals and insulators. The observed twofold oscillations in $\rho_{yx}$ as the magnetic field completes one rotation are the result of chiral, orbital and/or spin effects. The antiperovskites $A_3B$O ($A$ = Ca, Sr, Ba; $B$ = Sn, Pb) are topological crystalline insulators whose low-energy excitations are described by a generalized Dirac equation for fermions with total angular momentum $J = 3/2$. We report unusual sixfold oscillations in the PHE of Sr$_3$SnO, which persisted nearly up to room temperature. Multiple harmonics (twofold, fourfold and sixfold), which exhibited distinct field and temperature dependencies, were detected in $\rho_{xx}$ and $\rho_{yx}$. These observations are more diverse than those in other Dirac and Weyl semimetals and point to a richer interplay of microscopic processes underlying the PHE in the antiperovskites., Comment: 9 pages, 6 figures

Published
2021
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179. Interplanetary magnetic flux rope observed at ground level by HAWC

Author

Akiyama, S., Alfaro, R., Alvarez, C., Camacho, J. R. Angeles, Arteaga-Velázquez, J. C., Arunbabu, K. P., Rojas, D. Avila, Solares, H. A. Ayala, Belmont-Moreno, E., Caballero-Mora, K. S., Capistrán, T., Carramiñana, A., Casanova, S., Colin-Farias, P., Cotti, U., Cotzomi, J., De la Fuente, E., de León, C., Hernandez, R. Diaz, Espinoza, C., Fraija, N., Galván-Gámez, A., Garcia, D., García-González, J. A., Garfias, F., González, M. M., Goodman, J. A., Harding, J. P., Hona, B., Huang, D., Hueyotl-Zahuantitla, F., Huntemeyer, P., Iriarte, A., Joshi, V., Kieda, D., Kunde, G. J., Lara, A., Vargas, H. León, Luis-Raya, G., Malone, K., Martínez-Castro, J., Matthews, J. A., Miranda-Romagnoli, P., Moreno, E., Nayerhoda, A., Nellen, L., Newbold, M., Niembro, T., Nieves-Chinchilla, T., Noriega-Papaqui, R., Pérez-Pérez, E. G., Preisser, L., Rho, C. D., Ryan, J., Salazar, H., Greus, F. Salesa, Sandoval, A., Springer, R. W., Torres, I., Ureña-Mena, F., Villaseñor, L., and Zepeda, A.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract

We report the ground-level detection of a Galactic Cosmic-Ray (GCR) flux enhancement lasting $\sim$ 17 hr and associated with the passage of a magnetic flux rope (MFR) over the Earth. The MFR was associated with a slow Coronal Mass Ejection (CME) caused by the eruption of a filament on 2016 October 9. Due to the quiet conditions during the eruption and the lack of interactions during the interplanetary CME transport to the Earth, the associated MFR preserved its configuration and reached the Earth with a strong magnetic field, low density, and a very low turbulence level compared to the local background, thus generating the ideal conditions to redirect and guide GCRs (in the $\sim$ 8 to 60 GV rigidity range) along the magnetic field of the MFR. An important negative $B_Z$ component inside the MFR caused large disturbances in the geomagnetic field and a relatively strong geomagnetic storm. However, these disturbances are not the main factors behind the GCR enhancement. Instead, we found that the major factor was the alignment between the MFR axis and the asymptotic direction of the observer.

Published
2021
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180. Spectrum and Morphology of the Very-High-Energy Source HAWC J2019+368

Author

HAWC Collaboration, Albert, A., Alfaro, R., Alvarez, C., Arteaga-Velàzquez, J. C., Arunbabu, K. P., Rojas, D. Avila, Solares, H. A. Ayala, Baghmanyan, V., Belmont-Moreno, E., Brisbois, C., Caballero-Mora, K. S., Capistràn, T., Carramiñana, A., Casanova, S., Cotzomi, J., de León, S. Coutinõ, De la Fuente, E., Hernandez, R. Diaz, Dingus, B. L., DuVernois, M. A., Durocher, M., Engel, K., Espinoza, C., Fraija, N., Garcia, D., García-González, J. A., Giacinti, G., González, M. M., Goodman, J. A., Harding, J. P., Hinton, J., Hona, B., Huang, D., Hueyotl-Zahuantitla, F., Huentemeyer, P., Jardin-Blicq, A., Joshi, V., Lee, W. H., Vargas, H. León, Linnemann, J. T., Longinotti, A. L., Luis-Raya, G., Lundeen, J., López-Coto, R., Malone, K., Martinez, O., Martínez-Castro, J., Matthews, J. A., Miranda-Romagnoli, P., Morales-Soto, J. A., Moreno, E., Mostafá, M., Nayerhoda, A., Nellen, L., Newbold, M., Nisa, M. U., Noriega-Papaqui, R., Olivera-Nieto, L., Omodei, N., Peisker, A., Araujo, Y. Pérez, Pérez-Pérez, E. G., Rho, C. D., Rosa-Gonzàlez, D., Ruiz-Velasco, E., Salazar, H., Greus, F. Salesa, Sandoval, A., Schneider, M., Schoorlemmer, H., Serna-Franco, J., Smith, A. J., Springer, R. W., Surajbali, P., Tollefson, K., Torres, I., Turner, R., Urenã-Mena, F., Weisgarber, T., Willox, E., Zhou, H., and de León, C.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The MGRO J2019+37 region is one of the brightest sources in the sky at TeV energies. It was detected in the 2 year HAWC catalog as 2HWC J2019+367 and here we present a detailed study of this region using data from HAWC. This analysis resolves the region into two sources: HAWC J2019+368 and HAWC J2016+371. We associate HAWC J2016+371 with the evolved supernova remnant CTB 87, although its low significance in this analysis prevents a detailed study at this time. An investigation of the morphology (including possible energy dependent morphology) and spectrum for HAWC J2019+368 is the focus of this work. We associate HAWC J2019+368 with PSR J2021+3651 and its X-ray pulsar wind nebula, the Dragonfly nebula. Modeling the spectrum measured by HAWC and Suzaku reveals a $\sim$7 kyr pulsar and nebula system producing the observed emission at X-ray and ${\gamma}$-ray energies., Comment: Submitted to ApJ: 13 pages, 10 figures

Published
2021

181. Evidence of 200 TeV photons from HAWC J1825-134

Author

Albert, A., Alfaro, R., Alvarez, C., Camacho, J. R. Angeles, Arteaga-Velázquez, J. C., Arunbabu, K. P., Rojas, D. Avila, Solares, H. A. Ayala, Baghmanyan, V., Belmont-Moreno, E., BenZvi, S. Y., Brisbois, C., Capistrán, T., Carramiñana, A., Casanova, S., Cotti, U., Cotzomi, J., De la Fuente, E., Hernandez, R. Diaz, Dingus, B. L., DuVernois, M. A., Durocher, M., Díaz-Vélez, J. C., Engel, K., Espinoza, C., Fang, K., Fleischhack, H., Fraija, N., Galván-Gámez, A., Garcia, D., García-González, J. A., Garfias, F., Giacinti, G., González, M. M., Goodman, J. A., Harding, J. P., Hona, B., Huang, D., Hueyotl-Zahuantitla, F., Hüntemeyer, P., Iriarte, A., Jardin-Blicq, A., Joshi, V., Kunde, G. J., Lara, A., Lee, W. H., Vargas, H. León, Linnemann, J. T., Longinotti, A. L., Luis-Raya, G., Lundeen, J., Malone, K., Marandon, V., Martinez, O., Martínez-Castro, J., Matthews, J. A., Miranda-Romagnoli, P., Moreno, E., Mostafá, M., Nayerhoda, A., Nellen, L., Newbold, M., Nisa, M. U., Noriega-Papaqui, R., Omodei, N., Peisker, A., Araujo, Y. Pérez, Pérez-Pérez, E. G., Rho, C. D., Rosa-González, D., Salazar, H., Greus, F. Salesa, Sandoval, A., Schneider, M., Serna, F., Springer, R. W., Tollefson, K., Torres, I., Torres-Escobedo, R., Ureña-Mena, F., Villaseñor, L., Willox, E., Zhou, H., and de León, C.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The Earth is bombarded by ultra-relativistic particles, known as cosmic rays (CRs). CRs with energies up to a few PeV (=10$^{15}$ eV), the knee in the particle spectrum, are believed to have a Galactic origin. One or more factories of PeV CRs, or PeVatrons, must thus be active within our Galaxy. The direct detection of PeV protons from their sources is not possible since they are deflected in the Galactic magnetic fields. Hundred TeV $\gamma$-rays from decaying $\pi^0$, produced when PeV CRs collide with the ambient gas, can provide the decisive evidence of proton acceleration up to the knee. Here we report the discovery by the High Altitude Water Cherenkov (HAWC) observatory of the $\gamma$-ray source, HAWC~J1825-134, whose energy spectrum extends well beyond 200 TeV without a break or cutoff. The source is found to be coincident with a giant molecular cloud. The ambient gas density is as high as 700 protons/cm$^3$. While the nature of this extreme accelerator remains unclear, CRs accelerated to energies of several PeV colliding with the ambient gas likely produce the observed radiation., Comment: Accepted for publication in ApJL

Published
2020
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182. Construction and On-site Performance of the LHAASO WFCTA Camera

Author

Aharonian, F., An, Q., Axikegu, Bai, L. X., Bai, Y. X., Bao, Y. W., Bastieri, D., Bi, X. J., Bi, Y. J., Cai, H., Cai, J. T., Cao, Z., Chang, J., Chang, J. F., Chang, X. C., Chen, B. M., Chen, J., Chen, L., Chen, M. J., Chen, M. L., Chen, Q. H., Chen, S. H., Chen, S. Z., Chen, T. L., Chen, X. L., Chen, Y., Cheng, N., Cheng, Y. D., Cui, S. W., Cui, X. H., Cui, Y. D., Dai, B. Z., Dai, H. L., Dai, Z. G., Danzengluobu, della Volpe, D., Piazzoli, B. D'Ettorre, Dong, X. J., Fan, J. H., Fan, Y. Z., Fan, Z. X., Fang, J., Fang, K., Feng, C. F., Feng, L., Feng, S. H., Feng, Y. L., Gao, B., Gao, C. D., Gao, Q., Gao, W., Ge, M. M., Geng, L. S., Gong, G. H., Gou, Q. B., Gu, M. H., Guo, J. G., Guo, X. L., Guo, Y. Q., Guo, Y. Y., Han, Y. A., He, H. H., He, H. N., He, J. C., He, S. L., He, X. B., He, Y., Heller, M., Hor, Y. K., Hou, C., Hou, X., Hu, H. B., Hu, S., Hu, S. C., Hu, X. J., Huang, D. H., Huang, Q. L., Huang, W. H., Huang, X. T., Huang, Z. C., Ji, F., Ji, X. L., Jia, H. Y., Jiang, K., Jiang, Z. J., Jin, C., Kuleshov, D., Levochkin, K., Li, B. B., Li, C., Li, F., Li, H. B., Li, H. C., Li, H. Y., Li, J., Li, K., Li, W. L., Li, X., Li, X. R., Li, Y., Li, Y. Z., Li, Z., Liang, E. W., Liang, Y. F., Lin, S. J., Liu, B., Liu, C., Liu, D., Liu, H., Liu, H. D., Liu, J., Liu, J. L., Liu, J. S., Liu, J. Y., Liu, M. Y., Liu, R. Y., Liu, S. M., Liu, W., Liu, Y. N., Liu, Z. X., Long, W. J., Lu, R., Lv, H. K., Ma, B. Q., Ma, L. L., Ma, X. H., Mao, J. R., Masood, A., Mitthumsiri, W., Montaruli, T., Nan, Y. C., Pang, B. Y., Pattarakijwanich, P., Pei, Z. Y., Qi, M. Y., Ruffolo, D., Rulev, V., Sáiz, A., Shao, L., Shchegolev, O., Sheng, X. D., Shi, J. R., Song, H. C., Stenkin, Yu. V., Stepanov, V., Sun, Q. N., Sun, X. N., Sun, Z. B., Tam, P. H. T., Tang, Z. B., Tian, W. W., Wang, B. D., Wang, C., Wang, H., Wang, H. G., Wang, J. C., Wang, J. S., Wang, L. P., Wang, L. Y., Wang, R. N., Wang, W., Wang, X. G., Wang, X. J., Wang, X. Y., Wang, Y. D., Wang, Y. J., Wang, Y. P., Wang, Z., Wang, Z. H., Wang, Z. X., Wei, D. M., Wei, J. J., Wei, Y. J., Wen, T., Wu, C. Y., Wu, H. R., Wu, S., Wu, W. X., Wu, X. F., Xi, S. Q., Xia, J., Xia, J. J., Xiang, G. M., Xiao, G., Xiao, H. B., Xin, G. G., Xin, Y. L., Xing, Y., Xu, D. L., Xu, R. X., Xue, L., Yan, D. H., Yang, C. W., Yang, F. F., Yang, J. Y., Yang, L. L., Yang, M. J., Yang, R. Z., Yang, S. B., Yao, Y. H., Yao, Z. G., Ye, Y. M., Yin, L. Q., Yin, N., You, X. H., You, Z. Y., Yu, Y. H., Yuan, Q., Zeng, H. D., Zeng, T. X., Zeng, W., Zeng, Z. K., Zha, M., Zhai, X. X., Zhang, B. B., Zhang, H. M., Zhang, H. Y., Zhang, J. L., Zhang, J. W., Zhang, L., Zhang, L. X., Zhang, P. F., Zhang, P. P., Zhang, R., Zhang, S. R., Zhang, S. S., Zhang, X., Zhang, X. P., Zhang, Y., Zhang, Y. F., Zhang, Y. L., Zhao, B., Zhao, J., Zhao, L., Zhao, L. Z., Zhao, S. P., Zheng, F., Zheng, Y., Zhou, B., Zhou, H., Zhou, J. N., Zhou, P., Zhou, R., Zhou, X. X., Zhu, C. G., Zhu, F. R., Zhu, H., Zhu, K. J., and Zuo, X.

Subjects
Physics - Instrumentation and Detectors, Astrophysics - Instrumentation and Methods for Astrophysics, High Energy Physics - Experiment
Abstract

The focal plane camera is the core component of the Wide Field-of-view Cherenkov/fluorescence Telescope Array (WFCTA) of the Large High-Altitude Air Shower Observatory (LHAASO). Because of the capability of working under moonlight without aging, silicon photomultipliers (SiPM) have been proven to be not only an alternative but also an improvement to conventional photomultiplier tubes (PMT) in this application. Eighteen SiPM-based cameras with square light funnels have been built for WFCTA. The telescopes have collected more than 100 million cosmic ray events and preliminary results indicate that these cameras are capable of working under moonlight. The characteristics of the light funnels and SiPMs pose challenges (e.g. dynamic range, dark count rate, assembly techniques). In this paper, we present the design features, manufacturing techniques and performances of these cameras. Finally, the test facilities, the test methods and results of SiPMs in the cameras are reported here., Comment: 45 pages, 21 figures, article

Published
2020
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183. Tunneling-tip-induced collapse of the charge gap in the excitonic insulator Ta$_2$NiSe$_5$

Author

He, Q., Que, X., Zhou, L., Isobe, M., Huang, D., and Takagi, H.

Subjects
Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

Tuning many-body electronic phases by an external handle is of both fundamental and practical importance in condensed matter science. The tunability mirrors the underlying interactions, and gigantic electric, optical and magnetic responses to minute external stimuli can be anticipated in the critical region of phase change. The excitonic insulator is one of the exotic phases of interacting electrons, produced by the Coulomb attraction between a small and equal number of electrons and holes, leading to the spontaneous formation of exciton pairs in narrow-gap semiconductors/semimetals. The layered chalcogenide Ta$_2$NiSe$_5$ has been recently discussed as such an excitonic insulator with an excitation gap of ~250 meV below $T_c$ = 328 K. Here, we demonstrate a drastic collapse of the excitation gap in Ta$_2$NiSe$_5$ and the realization of a zero-gap state by moving the tip of a cryogenic scanning tunneling microscope towards the sample surface by a few angstroms. The collapse strongly suggests the many-body nature of the gap in the insulating state of Ta$_2$NiSe$_5$, consistent with the formation of an excitonic state. We argue that the collapse of the gap is driven predominantly by the electrostatic charge accumulation at the surface induced by the proximity of the tip and the resultant carrier doping of the excitonic insulator. Our results establish a novel phase-change function based on excitonic insulators.

Published
2020
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184. Changes in profile distribution and chemical properties of natural nanoparticles in paddy soils as affected by long-term rice cultivation

Author

HUANG, D, ZHU, X, XU, B, HE, Y, ZHANG, M, LIU, F, LIAN, Z, DAHLGREN, RA, BROOKES, PC, and XU, J

Subjects
natural nanoparticle evolution, soil chronosequence, soil cultivation age, soil genesis, soil nanoparticles, Soil Sciences, Plant Biology, Crop and Pasture Production, Agronomy & Agriculture
Abstract

Systematic studies on the genesis, properties, and distribution of natural nanoparticles (NNPs) in soil remain scarce. This study examined a soil chronosequence of continuous paddy field land use for periods ranging from 0 to 1 000 years to determine how NNPs in soil changed at the early stages of soil genesis in eastern China. Soil samples were collected from coastal reclaimed paddy fields that were cultivated for 0, 50, 100, 300, 700, and 1 000 years. Natural nanoparticles were isolated and characterized along with bulk soil samples (< 2-mm fraction) for selected physical and chemical properties. The NNP content increased with increasing soil cultivation age at 60 g m−2 year−1, which was related to decreasing soil electrical conductivity (172–1 297 µS cm−1) and NNP zeta potentials (from –22 to –36 mV) with increasing soil cultivation age. Changes in several NNP properties, such as pedogenic iron oxide and total organic carbon contents, were consistent with those of the bulk soils across the soil chronosequence. Notably, changes in NNP iron oxide content were obvious and illustrated active chemical weathering, pedogenesis, and potential impacts on the microbial community. Redundancy analysis demonstrated that the soil cultivation age was the most important factor affecting NNP properties, contributing 60.7% of the total variation. Cluster and principal component analysis (PCA) revealed splitting of NNP samples into age groups of 50–300 and 700–1 000 years, indicating rapid evolution of NNP properties, after an initial period of desalinization (approximately 50 years). Overall, this study provides new insights into NNP evolution in soil during pedogenesis and predicting their influences on agriculture and ecological risks over millennial-scale rice cultivation.

Published
2021

185. Improving sensitivity to low-mass dark matter in LUX using a novel electrode background mitigation technique

Author

LUX Collaboration, Akerib, D. S., Alsum, S., Araújo, H. M., Bai, X., Balajthy, J., Bang, J., Baxter, A., Bernard, E. P., Bernstein, A., Biesiadzinski, T. P., Boulton, E. M., Boxer, B., Brás, P., Burdin, S., Byram, D., Carmona-Benitez, M. C., Chan, C., Cutter, J. E., de Viveiros, L., Druszkiewicz, E., Fan, A., Fiorucci, S., Gaitskell, R. J., Ghag, C., Gilchriese, M. G. D., Gwilliam, C., Hall, C. R., Haselschwardt, S. J., Hertel, S. A., Hogan, D. P., Horn, M., Huang, D. Q., Ignarra, C. M., Jacobsen, R. G., Jahangir, O., Ji, W., Kamdin, K., Kazkaz, K., Khaitan, D., Korolkova, E. V., Kravitz, S., Kudryavtsev, V. A., Leason, E., Lenardo, B. G., Lesko, K. T., Liao, J., Lin, J., Lindote, A., Lopes, M. I., Manalaysay, A., Mannino, R. L., Marangou, N., McKinsey, D. N., Mei, D. -M., Morad, J. A., Murphy, A. St. J., Naylor, A., Nehrkorn, C., Nelson, H. N., Neves, F., Nilima, A., Oliver-Mallory, K. C., Palladino, K. J., Rhyne, C., Riffard, Q., Rischbieter, G. R. C., Rossiter, P., Shaw, S., Shutt, T. A., Silva, C., Solmaz, M., Solovov, V. N., Sorensen, P., Sumner, T. J., Swanson, N., Szydagis, M., Taylor, D. J., Taylor, R., Taylor, W. C., Tennyson, B. P., Terman, P. A., Tiedt, D. R., To, W. H., Tvrznikova, L., Utku, U., Vacheret, A., Vaitkus, A., Velan, V., Webb, R. C., White, J. T., Whitis, T. J., Witherell, M. S., Wolfs, F. L. H., Woodward, D., Xiang, X., Xu, J., and Zhang, C.

Subjects
High Energy Physics - Experiment, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Physics - Instrumentation and Detectors
Abstract

This paper presents a novel technique for mitigating electrode backgrounds that limit the sensitivity of searches for low-mass dark matter (DM) using xenon time projection chambers. In the LUX detector, signatures of low-mass DM interactions would be very low energy ($\sim$keV) scatters in the active target that ionize only a few xenon atoms and seldom produce detectable scintillation signals. In this regime, extra precaution is required to reject a complex set of low-energy electron backgrounds that have long been observed in this class of detector. Noticing backgrounds from the wire grid electrodes near the top and bottom of the active target are particularly pernicious, we develop a machine learning technique based on ionization pulse shape to identify and reject these events. We demonstrate the technique can improve Poisson limits on low-mass DM interactions by a factor of $2$-$7$ with improvement depending heavily on the size of ionization signals. We use the technique on events in an effective $5$ tonne$\cdot$day exposure from LUX's 2013 science operation to place strong limits on low-mass DM particles with masses in the range $m_{\chi}\in0.15$-$10$ GeV. This machine learning technique is expected to be useful for near-future experiments, such as LZ and XENONnT, which hope to perform low-mass DM searches with the stringent background control necessary to make a discovery., Comment: 14 pages, 13 figures

Published
2020
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186. The observation of the Crab Nebula with LHAASO-KM2A for the performance study

Author

Aharonian, F., An, Q., Axikegu, Bai, L. X., Bai, Y. X., Bao, Y. W., Bastieri, D., Bi, X. J., Bi, Y. J., Cai, H., Cai, J. T., Cao, Z., Chang, J., Chang, J. F., Chang, X. C., Chen, B. M., Chen, J., Chen, L., Chen, M. J., Chen, M. L., Chen, Q. H., Chen, S. H., Chen, S. Z., Chen, T. L., Chen, X. L., Chen, Y., Cheng, N., Cheng, Y. D., Cui, S. W., Cui, X. H., Cui, Y. D., Dai, B. Z., Dai, H. L., Dai, Z. G., Danzengluobu, della Volpe, D., Piazzoli, B. D'Ettorre, Dong, X. J., Fan, J. H., Fan, Y. Z., Fan, Z. X., Fang, J., Fang, K., Feng, C. F., Feng, L., Feng, S. H., Feng, Y. L., Gao, B., Gao, C. D., Gao, Q., Gao, W., Ge, M. M., Geng, L. S., Gong, G. H., Gou, Q. B., Gu, M. H., Guo, J. G., Guo, X. L., Guo, Y. Q., Guo, Y. Y., Han, Y. A., He, H. H., He, H. N., He, J. C., He, S. L., He, X. B., He, Y., Heller, M., Hor, Y. K., Hou, C., Hou, X., Hu, H. B., Hu, S., Hu, S. C., Hu, X. J., Huang, D. H., Huang, Q. L., Huang, W. H., Huang, X. T., Huang, Z. C., Ji, F., Ji, X. L., Jia, H. Y., Jiang, K., Jiang, Z. J., Jin, C., Kuleshov, D., Levochkin, K., Li, B. B., Li, C., Li, F., Li, H. B., Li, H. C., Li, H. Y., Li, J., Li, K., Li, W. L., Li, X., Li, X. R., Li, Y., Li, Y. Z., Li, Z., Liang, E. W., Liang, Y. F., Lin, S. J., Liu, B., Liu, C., Liu, D., Liu, H., Liu, H. D., Liu, J., Liu, J. L., Liu, J. S., Liu, J. Y., Liu, M. Y., Liu, R. Y., Liu, S. M., Liu, W., Liu, Y. N., Liu, Z. X., Long, W. J., Lu, R., Lv, H. K., Ma, B. Q., Ma, L. L., Ma, X. H., Mao, J. R., Masood, A., Mitthumsiri, W., Montaruli, T., Nan, Y. C., Pang, B. Y., Pattarakijwanich, P., Pei, Z. Y., Qi, M. Y., Ruffolo, D., Rulev, V., Sáiz, A., Shao, L., Shchegolev, O., Sheng, X. D., Shi, J. R., Song, H. C., Stenkin, Yu. V., Stepanov, V., Sun, Q. N., Sun, X. N., Sun, Z. B., Tam, P. H. T., Tang, Z. B., Tian, W. W., Wang, B. D., Wang, C., Wang, H., Wang, H. G., Wang, J. C., Wang, J. S., Wang, L. P., Wang, L. Y., Wang, R. N., Wang, W., Wang, X. G., Wang, X. J., Wang, X. Y., Wang, Y. D., Wang, Y. J., Wang, Y. P., Wang, Z., Wang, Z. H., Wang, Z. X., Wei, D. M., Wei, J. J., Wei, Y. J., Wen, T., Wu, C. Y., Wu, H. R., Wu, S., Wu, W. X., Wu, X. F., Xi, S. Q., Xia, J., Xia, J. J., Xiang, G. M., Xiao, G., Xiao, H. B., Xin, G. G., Xin, Y. L., Xing, Y., Xu, D. L., Xu, R. X., Xue, L., Yan, D. H., Yang, C. W., Yang, F. F., Yang, J. Y., Yang, L. L., Yang, M. J., Yang, R. Z., Yang, S. B., Yao, Y. H., Yao, Z. G., Ye, Y. M., Yin, L. Q., Yin, N., You, X. H., You, Z. Y., Yu, Y. H., Yuan, Q., Zeng, H. D., Zeng, T. X., Zeng, W., Zeng, Z. K., Zha, M., Zhai, X. X., Zhang, B. B., Zhang, H. M., Zhang, H. Y., Zhang, J. L., Zhang, J. W., Zhang, L., Zhang, L. X., Zhang, P. F., Zhang, P. P., Zhang, R., Zhang, S. R., Zhang, S. S., Zhang, X., Zhang, X. P., Zhang, Y., Zhang, Y. F., Zhang, Y. L., Zhao, B., Zhao, J., Zhao, L., Zhao, L. Z., Zhao, S. P., Zheng, F., Zheng, Y., Zhou, B., Zhou, H., Zhou, J. N., Zhou, P., Zhou, R., Zhou, X. X., Zhu, C. G., Zhu, F. R., Zhu, H., Zhu, K. J., and Zuo, X.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

As a sub-array of the Large High Altitude Air Shower Observatory (LHAASO), KM2A is mainly designed to cover a large fraction of the northern sky to hunt for gamma-ray sources at energies above 10 TeV. Even though the detector construction is still underway, a half of the KM2A array has been operating stably since the end of 2019. In this paper, we present the pipeline of KM2A data analysis and the first observation on the Crab Nebula, a standard candle in very high energy gamma-ray astronomy. We detect gamma-ray signals from the Crab Nebula in both energy ranges of 10$-$100 TeV and $>$100 TeV with high significance, by analyzing the KM2A data of 136 live days between December 2019 and May 2020. With the observations, we test the detector performance including angular resolution, pointing accuracy and cosmic ray background rejection power. The energy spectrum of the Crab Nebula in the energy range 10-250 TeV fits well with a single power-law function dN/dE =(1.13$\pm$0.05$_{stat}$$\pm$0.08$_{sys}$)$\times$10$^{-14}$$\cdot$(E/20TeV)$^{-3.09\pm0.06_{stat}\pm0.02_{sys}}$ cm$^{-2}$ s$^{-1}$ TeV$^{-1}$. It is consistent with previous measurements by other experiments. This opens a new window of gamma-ray astronomy above 0.1 PeV through which ultrahigh-energy gamma-ray new phenomena, such as cosmic PeVatrons, might be discovered., Comment: 13 pages, 15 figures,submitted to CPC

Published
2020
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187. HAWC and Fermi-LAT Detection of Extended Emission from the Unidentified Source 2HWC J2006+341

Author

Albert, A., Alfaro, R., Alvarez, C., Camacho, J. R. Angeles, Araya, M., Arteaga-Velázquez, J. C., Arunbabu, K. P., Rojas, D. Avila, Solares, H. A. Ayala, Baghmanyan, V., Belmont-Moreno, E., Brisbois, C., Caballero-Mora, K. S., Carramiñana, A., Casanova, S., Cotti, U., De la Fuente, E., de León, C., Hernandez, R. Diaz, Dingus, B. L., DuVernois, M. A., Durocher, M., Díaz-Vélez, J. C., Espinoza, C., Fleischhack, H., Fraija, N., Galván-Gámez, A., Garcia, D., García-González, J. A., Garfias, F., González, M. M., Goodman, J. A., Harding, J. P., Hona, B., Huang, D., Hueyotl-Zahuantitla, F., Hüntemeyer, P., Iriarte, A., Jardin-Blicq, A., Joshi, V., Vargas, H. León, Linnemann, J. T., Longinotti, A. L., López-Coto, R., Luis-Raya, G., Lundeen, J., Malone, K., Martinez, O., Martínez-Castro, J., Matthews, J. A., Miranda-Romagnoli, P., Moreno, E., Mostafá, M., Nellen, L., Nisa, M. U., Noriega-Papaqui, R., Omodei, N., Peisker, A., Pérez-Pérez, E. G., Rho, C. D., Rosa-González, D., Greus, F. Salesa, Sandoval, A., Schneider, M., Springer, R. W., Tollefson, K., Torres, I., Torres-Escobedo, R., Ureña-Mena, F., Villaseñor, L., Weisgarber, T., Willox, E., Zepeda, A., and Zhou, H.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The discovery of the TeV point source 2HWC J2006+341 was reported in the second HAWC gamma-ray catalog. We present a follow-up study of this source here. The TeV emission is best described by an extended source with a soft spectrum. At GeV energies, an extended source is significantly detected in Fermi-LAT data. The matching locations, sizes and spectra suggest that both gamma-ray detections correspond to the same source. Different scenarios for the origin of the emission are considered and we rule out an association to the pulsar PSR J2004+3429 due to extreme energetics required, if located at a distance of 10.8 kpc., Comment: 12 pages, 2 figures. To appear in ApJL

Published
2020
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188. A survey of active galaxies at TeV photon energies with the HAWC gamma-ray observatory

Author

Albert, A., Alvarez, C., Camacho, J. R. Angeles, Arteaga-Velázquez, J. C., Arunbabu, K. P., Rojas, D. Avila, Solares, H. A. Ayala, Baghmanyan, V., Belmont-Moreno, E., BenZvi, S. Y., Brisbois, C., Caballero-Mora, K. S., Capistrán, T., Carramiñana, A., Casanova, S., Cotti, U., Cotzomi, J., de León, S. Coutiño, De la Fuente, E., Dingus, B. L., DuVernois, M. A., Durocher, M., Díaz-Vélez, J. C., Engel, K., Espinoza, C., Fan, K. L., Alonso, M. Fernández, Fleischhack, H., Fraija, N., Galván-Gámez, A., García, D., García-González, J. A., Garfias, F., González, M. M., Goodman, J. A., Harding, J. P., Hernández, S., Hona, B., Huang, D., Hueyotl-Zahuantitla, F., Hüntemeyer, P., Iriarte, A., Jardin-Blicq, A., Joshi, V., Kieda, D., Lara, A., Lee, W. H., Vargas, H. León, Linnemann, J. T., Longinotti, A. L., Luis-Raya, G., Lundeen, J., Malone, K., Martínez, O., Martinez-Castellanos, I., Martínez-Castro, J., Matthews, J. A., Miranda-Romagnoli, P., Morales-Soto, J. A., Moreno, E., Mostafá, M., Nayerhoda, A., Nellen, L., Newbold, M., Nisa, M. U., Noriega-Papaqui, R., Olivera-Nieto, L., Peisker, A., Pérez-Pérez, E. G., Rho, C. D., Rosa-González, D., Ruiz-Velasco, E., Salazar, H., Greus, F. Salesa, Sandoval, A., Schneider, M., Schoorlemmer, H., Smith, A. J., Springer, R. W., Tollefson, K., Torres, I., Torres-Escobedo, R., Ureña-Mena, F., Villaseñor, L., Weisgarber, T., Willox, E., Zepeda, A., Zhou, H., and de León, C.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The High Altitude Water Cherenkov Gamma-Ray Observatory (HAWC) continuously detects TeV photons and particles within its large field-of-view, accumulating every day a deeper exposure of two thirds of the sky. We analyzed 1523~days of HAWC live data acquired over four and a half years, in a follow-up analysis of {138} nearby ($z<0.3$) active galactic nuclei from the {\em Fermi} 3FHL catalog culminating within $40^\circ$ of the zenith at Sierra Negra, the HAWC site. This search for persistent TeV emission used a maximum-likelihood analysis assuming intrinsic power-law spectra attenuated by pair production of gamma-ray photons with the extragalactic background light. HAWC clearly detects persistent emission from Mkn~421 and Mkn~501, the two brightest blazars in the TeV sky, at 65$\sigma$ and 17$\sigma$ level, respectively. {Weaker evidence for long-term emission is found for three other known very-high energy emitters:} the radiogalaxy M87 and the BL Lac objects VER~J0521+211 and 1ES~1215+303, the later two at $z\sim 0.1$. We find evidence for collective emission from the set of 30 previously reported very high-energy sources that excludes Mkn~421 and Mkn~501 with a random probability $\sim 10^{-5}$. Upper limits are presented for the sample under the power-law assumption and in the predefined (0.5-2.0), (2.0-8.0) and (8.0-32.0) TeV energy intervals., Comment: The HAWC survey of Fermi 3FHL AGNs: 30 pages, 13 figures. Submitted to the Astrophysical Journal

Published
2020
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189. Performance Study of Charcoal-based Radon Reduction Systems for Ultraclean Rare Event Detectors

Author

Arthurs, M., Huang, D. Q., Amarasinghe, C., Miller, E., and Lorenzon, W.

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

The continuous emanation of radon due to trace amounts of uranium and thorium in detector materials introduces radon to the active detection volume of low-background rare event search detectors. $^{222}$Rn produces a particularly problematic background in the physics region of interest by the ``naked'' beta decay of its $^{214}$Pb daughter nucleus. While charcoal-based adsorption traps are expected to be effective for radon reduction in auxiliary circulation loops that service the warm components of current {ton-scale} detectors at slow flow rates $(0.5-2\;SLPM)$, radon reduction in the entire circulation loop at high flow rates $\mathcal{O}({100s\;SLPM})$ is necessary to reach high sensitivity in future generation experiments. In this article we explore radon dynamics with a charcoal-based radon reduction system in the main circulation loop of time projection chamber detectors. We find that even for perfect radon traps, circulation speeds of $2,000\;SLPM$ are needed to reduce radon concentration in a 10\,ton detector by 90\%. This is faster by a factor of four than the highest circulation speeds currently achieved in dark matter detectors. We further find that the effectiveness of vacuum swing adsorption systems, which have been employed very successfully at reducing atmospheric radon levels in clean-rooms, is limited by the intrinsic radon activity of the charcoal adsorbent in ultra-low radon environments. Adsorbents with significantly lower intrinsic radon activity than in currently available activated charcoals would be necessary to build effective vacuum swing adsorption systems operated at room temperature for rare event search experiments. If such VSA systems are cooled to about $190\,K$, this requirement relaxes drastically., Comment: 22 pages, 16 figures

Published
2020

190. Multimessenger Gamma-Ray and Neutrino Coincidence Alerts using HAWC and IceCube sub-threshold Data

Author

Solares, H. A. Ayala, Coutu, S., DeLaunay, J. J., Fox, D. B., Grégoire, T., Keivani, A., Krauß, F., Mostafá, M., Murase, K., Turley, C. F., Albert, A., Alfaro, R., Alvarez, C., Camacho, J. R. Angeles, Arteaga-Velázquez, J. C., Arunbabu, K. P., Rojas, D. Avila, Belmont-Moreno, E., Brisbois, C., Caballero-Mora, K. S., Carramiñana, A., Casanova, S., Cotti, U., De la Fuente, E., Hernandez, R. Diaz, Dingus, B. L., DuVernois, M. A., Durocher, M., Díaz-Vélez, J. C., Espinoza, C., Fan, K. L., Fleischhack, H., Fraija, N., Galván-Gámez, A., Garcia, D., García-González, J. A., Garfias, F., González, M. M., Goodman, J. A., Harding, J. P., Hona, B., Huang, D., Hueyotl-Zahuantitla, F., Huntemeyer, P., Iriarte, A., Jardin-Blicq, A., Joshi, V., Vargas, H. León, Linnemann, J. T., Longinotti, A. L., Luis-Raya, G., Lundeen, J., Malone, K., Martinez, O., Martinez-Castellanos, I., Martínez-Castro, J., Matthews, J. A., Miranda-Romagnoli, P., Moreno, E., Nellen, L., Newbold, M., Nisa, M. U., Noriega-Papaqui, R., Peisker, A., Pérez-Pérez, E. G., Rho, C. D., Rosa-González, D., Salazar, H., Greus, F. Salesa, Sandoval, A., Smith, A. J., Springer, R. W., Tollefson, K., Torres, I., Torres-Escobedo, R., Ureña-Mena, F., Villaseñor, L., Weisgarber, T., Willox, E., Zepeda, A., Zhou, H., de León, C., Aartsen, M. G., Abbasi, R., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., Ahrens, M., Alispach, C., Amin, N. M., Andeen, K., Anderson, T., Ansseau, I., Anton, G., Argüelles, C., Auffenberg, J., Axani, S., Bagherpour, H., Bai, X., V., A. Balagopal, Barbano, A., Barwick, S. W., Bastian, B., Basu, V., Baum, V., Baur, S., Bay, R., Beatty, J. J., Becker, K. -H., Tjus, J. Becker, BenZvi, S., Berley, D., Bernardini, E., Besson, D. Z., Binder, G., Bindig, D., Blaufuss, E., Blot, S., Bohm, C., Böser, S., Botner, O., Böttcher, J., Bourbeau, E., Bourbeau, J., Bradascio, F., Braun, J., Bron, S., Brostean-Kaiser, J., Burgman, A., Buscher, J., Busse, R. S., Carver, T., Chen, C., Cheung, E., Chirkin, D., Choi, S., Clark, B. A., Clark, K., Classen, L., Coleman, A., Collin, G. H., Conrad, J. M., Coppin, P., Correa, P., Cowen, D. F., Cross, R., Dave, P., De Clercq, C., Dembinski, H., Deoskar, K., De Ridder, S., Desai, A., Desiati, P., de Vries, K. D., de Wasseige, G., de With, M., DeYoung, T., Dharani, S., Diaz, A., Dujmovic, H., Dunkman, M., Dvorak, E., Ehrhardt, T., Eller, P., Engel, R., Evenson, P. A., Fahey, S., Fazely, A. R., Felde, J., Fienberg, A., Filimonov, K., Finley, C., Franckowiak, A., Friedman, E., Fritz, A., Gaisser, T. K., Gallagher, J., Ganster, E., Garrappa, S., Gerhardt, L., Glauch, T., Glüsenkamp, T., Goldschmidt, A., Gonzalez, J. G., Grant, D., Griffith, Z., Griswold, S., Günder, M., Gündüz, M., Haack, C., Hallgren, A., Halliday, R., Halve, L., Halzen, F., Hanson, K., Hardin, J., Haungs, A., Hauser, S., Hebecker, D., Heereman, D., Heix, P., Helbing, K., Hellauer, R., Henningsen, F., Hickford, S., Hignight, J., Hill, C., Hill, G. C., Hoffman, K. D., Hoffmann, R., Hoinka, T., Hokanson-Fasig, B., Hoshina, K., Huang, F., Huber, M., Huber, T., Hultqvist, K., Hünnefeld, M., Hussain, R., In, S., Iovine, N., Ishihara, A., Jansson, M., Japaridze, G. S., Jeong, M., Jones, B. J. P., Jonske, F., Joppe, R., Kang, D., Kang, W., Kappes, A., Kappesser, D., Karg, T., Karl, M., Karle, A., Katz, U., Kauer, M., Kellermann, M., Kelley, J. L., Kheirandish, A., Kim, J., Kin, K., Kintscher, T., Kiryluk, J., Kittler, T., Klein, S. R., Koirala, R., Kolanoski, H., Köpke, L., Kopper, C., Kopper, S., Koskinen, D. J., Koundal, P., Kowalski, M., Krings, K., Krückl, G., Kulacz, N., Kurahashi, N., Kyriacou, A., Lanfranchi, J. L., Larson, M. J., Lauber, F., Lazar, J. P., Leonard, K., Leszczyńska, A., Li, Y., Liu, Q. R., Lohfink, E., Mariscal, C. J. Lozano, Lu, L., Lucarelli, F., Ludwig, A., Lünemann, J., Luszczak, W., Lyu, Y., Ma, W. Y., Madsen, J., Maggi, G., Mahn, K. B. M., Makino, Y., Mallik, P., Mancina, S., Mariş, I. C., Maruyama, R., Mase, K., Maunu, R., McNally, F., Meagher, K., Medici, M., Medina, A., Meier, M., Meighen-Berger, S., Merz, J., Meures, T., Micallef, J., Mockler, D., Momenté, G., Montaruli, T., Moore, R. W., Morse, R., Moulai, M., Muth, P., Nagai, R., Naumann, U., Neer, G., Nguyen, L. V., Niederhausen, H., Nowicki, S. C., Nygren, D. R., Pollmann, A. Obertacke, Oehler, M., Olivas, A., O'Murchadha, A., O'Sullivan, E., Pandya, H., Pankova, D. V., Park, N., Parker, G. K., Paudel, E. N., Peiffer, P., Heros, C. Pérez de los, Philippen, S., Pieloth, D., Pieper, S., Pinat, E., Pizzuto, A., Plum, M., Popovych, Y., Porcelli, A., Rodriguez, M. Prado, Price, P. B., Przybylski, G. T., Raab, C., Raissi, A., Rameez, M., Rauch, L., Rawlins, K., Rea, I. C., Rehman, A., Reimann, R., Relethford, B., Renschler, M., Renzi, G., Resconi, E., Rhode, W., Richman, M., Riedel, B., Robertson, S., Roellinghoff, G., Rongen, M., Rott, C., Ruhe, T., Ryckbosch, D., Cantu, D. Rysewyk, Safa, I., Herrera, S. E. Sanchez, Sandrock, A., Sandroos, J., Santander, M., Sarkar, S., Satalecka, K., Scharf, M., Schaufel, M., Schieler, H., Schlunder, P., Schmidt, T., Schneider, A., Schneider, J., Schröder, F. G., Schumacher, L., Sclafani, S., Seckel, D., Seunarine, S., Shefali, S., Silva, M., Smithers, B., Snihur, R., Soedingrekso, J., Soldin, D., Song, M., Spiczak, G. M., Spiering, C., Stachurska, J., Stamatikos, M., Stanev, T., Stein, R., Stettner, J., Steuer, A., Stezelberger, T., Stokstad, R. G., Strotjohann, N. L., Stürwald, T., Stuttard, T., Sullivan, G. W., Taboada, I., Tenholt, F., Ter-Antonyan, S., Terliuk, A., Tilav, S., Tomankova, L., Tönnis, C., Toscano, S., Tosi, D., Trettin, A., Tselengidou, M., Tung, C. F., Turcati, A., Turcotte, R., Ty, B., Unger, E., Elorrieta, M. A. Unland, Usner, M., Vandenbroucke, J., Van Driessche, W., van Eijk, D., van Eijndhoven, N., Vannerom, D., van Santen, J., Verpoest, S., Vraeghe, M., Walck, C., Wallace, A., Wallraff, M., Watson, T. B., Weaver, C., Weindl, A., Weiss, M. J., Weldert, J., Wendt, C., Werthebach, J., Whelan, B. J., Whitehorn, N., Wiebe, K., Wiebusch, C. H., Williams, D. R., Wills, L., Wolf, M., Wood, T. R., Woschnagg, K., Wrede, G., Wulff, J., Xu, X. W., Xu, Y., Yanez, J. P., Yoshida, S., Yuan, T., Zhang, Z., and Zöcklein, M.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The High Altitude Water Cherenkov (HAWC) and IceCube observatories, through the Astrophysical Multimessenger Observatory Network (AMON) framework, have developed a multimessenger joint search for extragalactic astrophysical sources. This analysis looks for sources that emit both cosmic neutrinos and gamma rays that are produced in photo-hadronic or hadronic interactions. The AMON system is running continuously, receiving sub-threshold data (i.e. data that is not suited on its own to do astrophysical searches) from HAWC and IceCube, and combining them in real-time. We present here the analysis algorithm, as well as results from archival data collected between June 2015 and August 2018, with a total live-time of 3.0 years. During this period we found two coincident events that have a false alarm rate (FAR) of $<1$ coincidence per year, consistent with the background expectations. The real-time implementation of the analysis in the AMON system began on November 20th, 2019, and issues alerts to the community through the Gamma-ray Coordinates Network with a FAR threshold of $<4$ coincidences per year., Comment: 14 pages, 5 figures, 3 tables

Published
2020
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191. Current-induced nonreciprocity and refraction-free propagation in a one-dimensional graphene-based photonic crystal

Author

Huang, D. P. and Xu, K. Y.

Subjects
Physics - Optics
Abstract

Nonreciprocal photonic devices play a significant role in regulating the propagation of electromagnetic waves. Here we theoretically investigate the nonreciprocal properties of transverse magnetic modes in a one-dimensional graphene-based photonic crystal subjected to an applied electrical DC bias. We find that drifting electrons driven by the external DC electric field can give rise to extremely asymmetric dispersion diagrams. Furthermore, when the drifting electrons travel antiparallel to the normal component of the incident wave vector, the negative refraction is strongly suppressed, causing the energy of light to flow along the direction of the direct electric current. Our theoretical findings can be used to design nonreciprocal nanophotonic devices and enable light to propagate without refraction., Comment: 10 pages, 4 figures

Published
2020
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192. 3HWC: The Third HAWC Catalog of Very-High-Energy Gamma-ray Sources

Author

Albert, A., Alfaro, R., Alvarez, C., Camacho, J. R. Angeles, Arteaga-Velázquez, J. C., Arunbabu, K. P., Rojas, D. Avila, Solares, H. A. Ayala, Baghmanyan, V., Belmont-Moreno, E., BenZvi, S. Y., Brisbois, C., Caballero-Mora, K. S., Capistrán, T., Carramiñana, A., Casanova, S., Cotti, U., de León, S. Coutiño, De la Fuente, E., Hernandez, R. Diaz, Diaz-Cruz, L., Dingus, B. L., DuVernois, M. A., Durocher, M., Díaz-Vélez, J. C., Ellsworth, R. W., Engel, K., Espinoza, C., Fan, K. L., Fang, K., Alonso, M. Fernández, Fleischhack, H., Fraija, N., Galván-Gámez, A., Garcia, D., García-González, J. A., Garfias, F., Giacinti, G., González, M. M., Goodman, J. A., Harding, J. P., Hernandez, S., Hinton, J., Hona, B., Huang, D., Hueyotl-Zahuantitla, F., Hüntemeyer, P., Iriarte, A., Jardin-Blicq, A., Joshi, V., Kieda, D., Lara, A., Lee, W. H., Vargas, H. León, Linnemann, J. T., Longinotti, A. L., Luis-Raya, G., Lundeen, J., López-Coto, R., Malone, K., Marandon, V., Martinez, O., Martinez-Castellanos, I., Martínez-Castro, J., Matthews, J. A., Miranda-Romagnoli, P., Morales-Soto, J. A., Moreno, E., Mostafá, M., Nayerhoda, A., Nellen, L., Newbold, M., Nisa, M. U., Noriega-Papaqui, R., Olivera-Nieto, L., Omodei, N., Peisker, A., Araujo, Y. Pérez, Pérez-Pérez, E. G., Ren, Z., Rho, C. D., Rivière, C., Rosa-González, D., Ruiz-Velasco, E., Salazar, H., Greus, F. Salesa, Sandoval, A., Schneider, M., Schoorlemmer, H., Serna, F., Sinnis, G., Smith, A. J., Springer, R. W., Surajbali, P., Tabachnick, E., Tollefson, K., Torres, I., Torres-Escobedo, R., Ukwatta, T. N., Ureña-Mena, F., Weisgarber, T., Werner, F., Willox, E., Zepeda, A., Zhou, H., de León, C., and Álvarez, J. D.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

We present a new catalog of TeV gamma-ray sources using 1523 days of data from the High Altitude Water Cherenkov (HAWC) observatory. The catalog represents the most sensitive survey of the Northern gamma-ray sky at energies above several TeV, with three times the exposure compared to the previous HAWC catalog, 2HWC. We report 65 sources detected at $\geq$ 5 sigma significance, along with the positions and spectral fits for each source. The catalog contains eight sources that have no counterpart in the 2HWC catalog, but are within $1^\circ$ of previously detected TeV emitters, and twenty sources that are more than $1^\circ$ away from any previously detected TeV source. Of these twenty new sources, fourteen have a potential counterpart in the fourth \textit{Fermi} Large Area Telescope catalog of gamma-ray sources. We also explore potential associations of 3HWC sources with pulsars in the ATNF pulsar catalog and supernova remnants in the Galactic supernova remnant catalog., Comment: 20 pages, 11 figures. Matches the version published in The Astrophysical Journal. See accompanying data release at https://data.hawc-observatory.org/datasets/3hwc-survey/index.php

Published
2020
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193. Acoustic plasmons and conducting carriers in hole-doped cuprate superconductors

Author

Singh, A., Huang, H. Y., Lane, Christopher, Li, J. H., Okamoto, J., Komiya, S., Markiewicz, Robert S., Bansil, Arun, Fujimori, A., Chen, C. T., and Huang, D. J.

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

The superconductivity of cuprates, which has been a mystery ever since its discovery decades ago, is created through doping electrons or holes into a Mott insulator. There, however, exists an inherent electron-hole asymmetry in cuprates. The layered crystal structures of cuprates enable collective charge excitations fundamentally different from those of three-dimensional metals, i.e., acoustic plasmons. Acoustic plasmons have been recently observed in electron-doped cuprates by resonant inelastic X-ray scattering (RIXS); in contrast, there is no evidence for acoustic plasmons in hole-doped cuprates, despite extensive measurements. This contrast led us to investigate whether the doped holes in cuprates La$_{2-x}$Sr$_x$CuO$_4$ are conducting carriers or are too incoherent to induce collective charge excitation. Here we present momentum-resolved RIXS measurements and calculations of collective charge response via the loss function to reconcile the aforementioned issues. Our results provide unprecedented spectroscopic evidence for the acoustic plasmons and long sought conducting p holes in hole-doped cuprates.

Published
2020
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194. Development of the Soft X-ray AGM-AGS RIXS Beamline at Taiwan Photon Source

Author

Singh, A., Huang, H. Y., Chu, Y. Y., Hua, C. Y., Lin, S. W., Fung, H. S., Shiu, H. W., Chang, J., Li, J. H., Okamoto, J., Chiu, C. C., Chang, C. H., Wu, W. B., Perng, S. Y., Chung, S. C., Kao, K. Y., Yeh, S. C., Chao, H. Y., Chen, J. H., Huang, D. J., and Chen, C. T.

Subjects
Physics - Instrumentation and Detectors, Condensed Matter - Strongly Correlated Electrons
Abstract

We report on the development of a high-resolution and highly efficient beamline for soft-X-ray resonant inelastic X-ray scattering (RIXS) located at Taiwan Photon Source. This beamline adopts an optical design that uses an active grating monochromator (AGM) and an active grating spectrometer (AGS) to implement the energy compensation principle of grating dispersion. Active gratings are utilized to diminish defocus, coma and higher-order aberrations as well as to decrease the slope errors caused by thermal deformation and optical polishing. The AGS is mounted on a rotatable granite platform to enable momentum-resolved RIXS measurements with scattering angle over a wide range. Several high-precision instruments developed in house for this beamline are briefly described. The best energy resolution obtained from this AGM-AGS beamline was 12.4 meV at 530 eV, achieving a resolving power 42,000, while the bandwidth of the incident soft X-rays was kept at 0.5 eV. To demonstrate the scientific impacts of high-resolution RIXS, we present an example of momentum-resolved RIXS measurements on a high-temperature superconducting cuprate, La$_{2-x}$Sr$_x$CuO$_4$. The measurements reveal the A$_{1g}$ apical oxygen phonons in superconducting cuprates, opening a new opportunity to investigate the coupling between these phonons and charge density waves., Comment: 9 pages, p figures, submitted to J. of Synchrotron Radiation. Revise expression

Published
2020
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195. New sensitivity of current LHC measurements to vector-like quarks

Author

Buckley, A., Butterworth, J. M., Corpe, L., Huang, D., and Sun, P.

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

Quark partners with non-chiral couplings appear in several extensions of the Standard Model. They may have non-trivial generational structure to their couplings, and may be produced either in pairs via the strong and EM interactions, or singly via the new couplings of the model. Their decays often produce heavy quarks and gauge bosons, which will contribute to a variety of already-measured "Standard Model" cross-sections at the LHC. We present a study of the sensitivity of such published LHC measurements to vector-like quarks, first comparing to limits already obtained from dedicated searches, and then broadening to some so-far unstudied parameter regions.

Published
2020
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196. The LUX-ZEPLIN (LZ) radioactivity and cleanliness control programs

Author

Akerib, D. S., Akerlof, C. W., Akimov, D. Yu., Alquahtani, A., Alsum, S. K., Anderson, T. J., Angelides, N., Araújo, H. M., Arbuckle, A., Armstrong, J. E., Arthurs, M., Auyeung, H., Aviles, S., Bai, X., Bailey, A. J., Balajthy, J., Balashov, S., Bang, J., Barry, M. J., Bauer, D., Bauer, P., Baxter, A., Belle, J., Beltrame, P., Bensinger, J., Benson, T., Bernard, E. P., Bernstein, A., Bhatti, A., Biekert, A., Biesiadzinski, T. P., Birch, H. J., Birrittella, B., Boast, K. E., Bolozdynya, A. I., Boulton, E. M., Boxer, B., Bramante, R., Branson, S., Brás, P., Breidenbach, M., Brew, C. A. J., Buckley, J. H., Bugaev, V. V., Bunker, R., Burdin, S., Busenitz, J. K., Cabrita, R., Campbell, J. S., Carels, C., Carlsmith, D. L., Carlson, B., Carmona-Benitez, M. C., Cascella, M., Chan, C., Cherwinka, J. J., Chiller, A. A., Chiller, C., Chott, N. I., Cole, A., Coleman, J., Colling, D., Conley, R. A., Cottle, A., Coughlen, R., Cox, G., Craddock, W. W., Curran, D., Currie, A., Cutter, J. E., da Cunhaw, J. P., Dahl, C. E., Dardin, S., Dasu, S., Davis, J., Davison, T. J. R., de Viveiros, L., Decheine, N., Dobi, A., Dobson, J. E. Y., Druszkiewicz, E., Dushkin, A., Edberg, T. K., Edwards, W. R., Edwards, B. N., Edwards, J., Elnimr, M. M., Emmet, W. T., Eriksen, S. R., Faham, C. H., Fan, A., Fayer, S., Fiorucci, S., Flaecher, H., Florang, I. M. Fogarty, Ford, P., Francis, V. B., Fraser, E. D., Froborg, F., Fruth, T., Gaitskell, R. J., Gantos, N. J., Garcia, D., Gehman, V. M., Gelfand, R., Genovesi, J., Gerhard, R. M., Ghag, C., Gibson, E., Gilchriese, M. G. D., Gokhale, S., Gomber, B., Gonda, T. G., Greenall, A., Greenwood, S., Gregerson, G., van der Grinten, M. G. D., Gwilliam, C. B., Hall, C. R., Hamilton, D., Hans, S., Hanzel, K., Harrington, T., Harrison, A., Harrison, J., Hasselkus, C., Haselschwardt, S. J., Hemer, D., Hertel, S. A., Heise, J., Hillbrand, S., Hitchcock, O., Hjemfelt, C., Hoff, M. D., Holbrook, B., Holtom, E., Hor, J. Y-K., Horn, M., Huang, D. Q., Hurteau, T. W., Ignarra, C. M., Irving, M. N., Jacobsen, R. G., Jahangir, O., Jeffery, S. N., Ji, W., Johnson, M., Johnson, J., Johnson, P., Jones, W. G., Kaboth, A. C., Kamaha, A., Kamdin, K., Kasey, V., Kazkaz, K., Keefner, J., Khaitan, D., Khaleeq, M., Khazov, A., Khromov, A. V., Khurana, I., Kim, Y. D., Kim, W. T., Kocher, C. D., Kodroff, D., Konovalov, A. M., Korley, L., Korolkova, E. V., Koyuncu, M., Kras, J., Kraus, H., Kravitz, S. W., Krebs, H. J., Kreczko, L., Krikler, B., Kudryavtsev, V. A., Kumpan, A. V., Kyre, S., Lambert, A. R., Landerud, B., Larsen, N. A., Laundrie, A., Leason, E. A., Lee, H. S., Lee, J., Lee, C., Lenardo, B. G., Leonard, D. S., Leonard, R., Lesko, K. T., Levy, C., Li, J., Liu, Y., Liao, J., Liao, F. -T., Lin, J., Lindote, A., Linehan, R., Lippincott, W. H., Liu, R., Liu, X., Loniewski, C., Lopes, M. I., Lopez-Asamar, E., Paredes, B. López, Lorenzon, W., Lucero, D., Luitz, S., Lyle, J. M., Lynch, C., Majewski, P. A., Makkinje, J., Malling, D. C., Manalaysay, A., Manenti, L., Mannino, R. L., Marangou, N., Markley, D. J., MarrLaundrie, P., Martin, T. J., Marzioni, M. F., Maupin, C., McConnell, C. T., McKinsey, D. N., McLaughlin, J., Mei, D. -M., Meng, Y., Miller, E. H., Minaker, Z. J., Mizrachi, E., Mock, J., Molash, D., Monte, A., Monzani, M. E., Morad, J. A., Morrison, E., Mount, B. J., Murphy, A. St. J., Naim, D., Naylor, A., Nedlik, C., Nehrkorn, C., Nelson, H. N., Nesbit, J., Neves, F., Nikkel, J. A., Nikoleyczik, J. A., Nilima, A., O'Dell, J., Oh, H., O'Neill, F. G., O'Sullivan, K., Olcina, I., Olevitch, M. A., Oliver-Mallory, K. C., Oxborough, L., Pagac, A., Pagenkopf, D., Pal, S., Palladino, K. J., Palmaccio, V. M., Palmer, J., Pangilinan, M., Parveen, N., Patton, S. J., Pease, E. K., Penning, B. P., Pereira, G., Pereira, C., Peterson, I. B., Piepke, A., Pierson, S., Powell, S., Preece, R. M., Pushkin, K., Qie, Y., Racine, M., Ratcliff, B. N., Reichenbacher, J., Reichhart, L., Rhyne, C. A., Richards, A., Riffard, Q., Rischbieter, G. R. C., Rodrigues, J. P., Rose, H. J., Rosero, R., Rossiter, P., Rucinski, R., Rutherford, G., Saba, J. S., Sabarots, L., Santone, D., Sarychev, M., Sazzad, A. B. M. R., Schnee, R. W., Schubnell, M., Scovell, P. R., Severson, M., Seymour, D., Shaw, S., Shutt, G. W., Shutt, T. A., Silk, J. J., Silva, C., Skarpaas, K., Skulski, W., Smith, A. R., Smith, R. J., Smith, R. E., So, J., Solmaz, M., Solovov, V. N., Sorensen, P., Sosnovtsev, V. V., Stancu, I., Stark, M. R., Stephenson, S., Stern, N., Stevens, A., Stiegler, T. M., Stifter, K., Studley, R., Sumner, T. J., Sundarnath, K., Sutcliffe, P., Swanson, N., Szydagis, M., Tan, M., Taylor, W. C., Taylor, R., Taylor, D. J., Temples, D., Tennyson, B. P., Terman, P. A., Thomas, K. J., Thomson, J. A., Tiedt, D. R., Timalsina, M., To, W. H., Tomás, A., Tope, T. E., Tripathi, M., Tronstad, D. R., Tull, C. E., Turner, W., Tvrznikova, L., Utes, M., Utku, U., Uvarov, S., Va'vra, J., Vacheret, A., Vaitkus, A., Verbus, J. R., Vietanen, T., Voirin, E., Vuosalo, C. O., Walcott, S., Waldron, W. L., Walker, K., Wang, J. J., Wang, R., Wang, L., Wang, W., Wang, Y., Watson, J. R., Migneault, J., Weatherly, S., Webb, R. C., Wei, W. -Z., While, M., White, R. G., White, J. T., White, D. T., Whitis, T. J., Wisniewski, W. J., Wilson, K., Witherell, M. S., Wolfs, F. L. H., Wolfs, J. D., Woodward, D., Worm, S. D., Xiang, X., Xiao, Q., Xu, J., Yeh, M., Yin, J., Young, I., Zhang, C., and Zarzhitsky, P.

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

LUX-ZEPLIN (LZ) is a second-generation direct dark matter experiment with spin-independent WIMP-nucleon scattering sensitivity above $1.4 \times 10^{-48}$ cm$^{2}$ for a WIMP mass of 40 GeV/c$^{2}$ and a 1000 d exposure. LZ achieves this sensitivity through a combination of a large 5.6 t 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., Comment: 45 pages (79 inc. tables), 7 figures, 9 tables

Published
2020
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197. HAWC J2227+610 and its association with G106.3+2.7, a new potential Galactic PeVatron

Author

Albert, A., Alfaro, R., Alvarez, C., Camacho, J. R. Angeles, Arteaga-Velázquez, J. C., Arunbabu, K. P., Rojas, D. Avila, Solares, H. A. Ayala, Baghmanyan, V., Belmont-Moreno, E., BenZvi, S. Y., Brisbois, C., Caballero-Mora, K. S., Capistrán, T., Carramiñana, A., Casanova, S., Cotti, U., Cotzomi, J., de León, S. Coutiño, De la Fuente, E., Diaz-Cruz, L., Dingus, B. L., DuVernois, M. A., Díaz-Vélez, J. C., Ellsworth, R. W., Engel, K., Espinoza, C., Fan, K. L., Fang, K., Alonso, M. Fernández, Fleischhack, H., Fraija, N., Galván-Gámez, A., Garcia, D., García-González, J. A., Garfias, F., Giacinti, G., González, M. M., Goodman, J. A., Harding, J. P., Hernandez, S., Hinton, J., Hona, B., Huang, D., Hueyotl-Zahuantitla, F., Hüntemeyer, P., Iriarte, A., Jardin-Blicq, A., Joshi, V., Lee, W. H., Vargas, H. León, Linnemann, J. T., Longinotti, A. L., Luis-Raya, G., Lundeen, J., Malone, K., Marinelli, S. S., Martinez, O., Martinez-Castellanos, I., Martínez-Castro, J., Matthews, J. A., Miranda-Romagnoli, P., Morales-Soto, J. A., Moreno, E., Mostafá, M., Nayerhoda, A., Nellen, L., Newbold, M., Nisa, M. U., Noriega-Papaqui, R., Omodei, N., Peisker, A., Araujo, Y. Pérez, Pérez-Pérez, E. G., Rho, C. D., Rosa-González, D., Ruiz-Velasco, E., Salazar, H., Greus, F. Salesa, Sandoval, A., Schneider, M., Schoorlemmer, H., Franco, J. Serna, Sinnis, G., Smith, A. J., Springer, R. W., Surajbali, P., Tabachnick, E., Tanner, M., Tibolla, O., Tollefson, K., Torres, I., Torres-Escobedo, R., Ureña-Mena, F., Villaseñor, L., Weisgarber, T., Zepeda, A., Zhou, H., de León, C., and Álvarez, J. D.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We present the detection of VHE gamma-ray emission above 100 TeV from HAWC J2227+610 with the HAWC observatory. Combining our observations with previously published results by VERITAS, we interpret the gamma-ray emission from HAWC J2227+610 as emission from protons with a lower limit in their cutoff energy of 800 TeV. The most likely source of the protons is the associated supernova remnant G106.3+2.7, making it a good candidate for a Galactic PeVatron. However, a purely leptonic origin of the observed emission cannot be excluded at this time., Comment: Accepted for publication by ApJL

Published
2020
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198. Investigation of background electron emission in the LUX detector

Author

Akerib, D. S., Alsum, S., Araújo, H. M., Bai, X., Balajthy, J., Baxter, A., Bernard, E. P., Bernstein, A., Biesiadzinski, T. P., Boulton, E. M., Boxer, B., Brás, P., Burdin, S., Byram, D., Carmona-Benitez, M. C., Chan, C., Cutter, J. E., de Viveiros, L., Druszkiewicz, E., Fan, A., Fiorucci, S., Gaitskell, R. J., Ghag, C., Gilchriese, M. G. D., Gwilliam, C., Hall, C. R., Haselschwardt, S. J., Hertel, S. A., Hogan, D. P., Horn, M., Huang, D. Q., Ignarra, C. M., Jacobsen, R. G., Jahangir, O., Ji, W., Kamdin, K., Kazkaz, K., Khaitan, D., Korolkova, E. V., Kravitz, S., Kudryavtsev, V. A., Leason, E., Lenardo, B. G., Lesko, K. T., Liao, J., Lin, J., Lindote, A., Lopes, M. I., Manalaysay, A., Mannino, R. L., Marangou, N., McKinsey, D. N., Mei, D. M., Moongweluwan, M., Morad, J. A., Murphy, A. St. J., Naylor, A., Nehrkorn, C., Nelson, H. N., Neves, F., Nilima, A., Oliver-Mallory, K. C., Palladino, K. J., Pease, E. K., Riffard, Q., Rischbieter, G. R. C., Rhyne, C., Rossiter, P., Shaw, S., Shutt, T. A., Silva, C., Solmaz, M., Solovov, V. N., Sorensen, P., Sumner, T. J., Szydagis, M., Taylor, D. J., Taylor, R., Taylor, W. C., Tennyson, B. P., Terman, P. A., Tiedt, D. R., To, W. H., Tvrznikova, L., Utku, U., Uvarov, S., Vacheret, A., Velan, V., Webb, R. C., White, J. T., Whitis, T. J., Witherell, M. S., Wolfs, F. L. H., Woodward, D., Xu, J., and Zhang, C.

Subjects
Physics - Instrumentation and Detectors
Abstract

Dual-phase xenon detectors, as currently used in direct detection dark matter experiments, have observed elevated rates of background electron events in the low energy region. While this background negatively impacts detector performance in various ways, its origins have only been partially studied. In this paper we report a systematic investigation of the electron pathologies observed in the LUX dark matter experiment. We characterize different electron populations based on their emission intensities and their correlations with preceding energy depositions in the detector. By studying the background under different experimental conditions, we identified the leading emission mechanisms, including photoionization and the photoelectric effect induced by the xenon luminescence, delayed emission of electrons trapped under the liquid surface, capture and release of drifting electrons by impurities, and grid electron emission. We discuss how these backgrounds can be mitigated in LUX and future xenon-based dark matter experiments., Comment: 17 pages, 13 figures

Published
2020
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199. Discrimination of electronic recoils from nuclear recoils in two-phase xenon time projection chambers

Author

LUX Collaboration, Akerib, D. S., Alsum, S., Araújo, H. M., Bai, X., Balajthy, J., Baxter, A., Bernard, E. P., Bernstein, A., Biesiadzinski, T. P., Boulton, E. M., Boxer, B., Brás, P., Burdin, S., Byram, D., Carmona-Benitez, M. C., Chan, C., Cutter, J. E., de Viveiros, L., Druszkiewicz, E., Fan, A., Fiorucci, S., Gaitskell, R. J., Ghag, C., Gilchriese, M. G. D., Gwilliam, C., Hall, C. R., Haselschwardt, S. J., Hertel, S. A., Hogan, D. P., Horn, M., Huang, D. Q., Ignarra, C. M., Jacobsen, R. G., Jahangir, O., Ji, W., Kamdin, K., Kazkaz, K., Khaitan, D., Korolkova, E. V., Kravitz, S., Kudryavtsev, V. A., Leason, E., Lenardo, B. G., Lesko, K. T., Liao, J., Lin, J., Lindote, A., Lopes, M. I., Manalaysay, A., Mannino, R. L., Marangou, N., McKinsey, D. N., Mei, D. -M., Moongweluwan, M., Morad, J. A., Murphy, A. St. J., Naylor, A., Nehrkorn, C., Nelson, H. N., Neves, F., Nilima, A., Oliver-Mallory, K. C., Palladino, K. J., Pease, E. K., Riffard, Q., Rischbieter, G. R. C., Rhyne, C., Rossiter, P., Shaw, S., Shutt, T. A., Silva, C., Solmaz, M., Solovov, V. N., Sorensen, P., Sumner, T. J., Szydagis, M., Taylor, D. J., Taylor, R., Taylor, W. C., Tennyson, B. P., Terman, P. A., Tiedt, D. R., To, W. H., Tvrznikova, L., Utku, U., Uvarov, S., Vacheret, A., Velan, V., Webb, R. C., White, J. T., Whitis, T. J., Witherell, M. S., Wolfs, F. L. H., Woodward, D., Xu, J., and Zhang, C.

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

We present a comprehensive analysis of electronic recoil vs. nuclear recoil discrimination in liquid/gas xenon time projection chambers, using calibration data from the 2013 and 2014-16 runs of the Large Underground Xenon (LUX) experiment. We observe strong charge-to-light discrimination enhancement with increased event energy. For events with S1 = 120 detected photons, i.e. equivalent to a nuclear recoil energy of $\sim$100 keV, we observe an electronic recoil background acceptance of $<10^{-5}$ at a nuclear recoil signal acceptance of 50%. We also observe modest electric field dependence of the discrimination power, which peaks at a field of around 300 V/cm over the range of fields explored in this study (50-500 V/cm). In the WIMP search region of S1 = 1-80 phd, the minimum electronic recoil leakage we observe is ${(7.3\pm0.6)\times10^{-4}}$, which is obtained for a drift field of 240-290 V/cm. Pulse shape discrimination is utilized to improve our results, and we find that, at low energies and low fields, there is an additional reduction in background leakage by a factor of up to 3. We develop an empirical model for recombination fluctuations which, when used alongside the Noble Element Scintillation Technique (NEST) simulation package, correctly reproduces the skewness of the electronic recoil data. We use this updated simulation to study the width of the electronic recoil band, finding that its dominant contribution comes from electron-ion recombination fluctuations, followed in magnitude of contribution by fluctuations in the S1 signal, fluctuations in the S2 signal, and fluctuations in the total number of quanta produced for a given energy deposition., Comment: 29 pages, 33 figures; minor typos corrected, references updated

Published
2020
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200. An Effective Field Theory Analysis of the First LUX Dark Matter Search

Author

Akerib, D. S., Alsum, S., Araújo, H. M., Bai, X., Balajthy, J., Baxter, A., Bernard, E. P., Bernstein, A., Biesiadzinski, T. P., Boulton, E. M., Boxer, B., Brás, P., Burdin, S., Byram, D., Carmona-Benitez, M. C., Chan, C., Cutter, J. E., de Viveiros, L., Druszkiewicz, E., Fan, A., Fiorucci, S., Gaitskell, R. J., Ghag, C., Gilchriese, M. G. D., Gwilliam, C., Hall, C. R., Haselschwardt, S. J., Hertel, S. A., Hogan, D. P., Horn, M., Huang, D. Q., Ignarra, C. M., Jacobsen, R. G., Jahangir, O., Ji, W., Kamdin, K., Kazkaz, K., Khaitan, D., Korolkova, E. V., Kravitz, S., Kudryavtsev, V. A., Larsen, N. A., Leason, E., Lenardo, B. G., Lesko, K. T., Liao, J., Lin, J., Lindote, A., Lopes, M. I., Manalaysay, A., Mannino, R. L., Marangou, N., McKinsey, D. N., Mei, D. -M., Moongweluwan, M., Morad, J. A., Murphy, A. St. J., Naylor, A., Nehrkorn, C., Nelson, H. N., Neves, F., Nilima, A., Oliver-Mallory, K. C., Palladino, K. J., Pease, E. K., Riffard, Q., Rischbieter, G. R. C., Rhyne, C., Rossiter, P., Shaw, S., Shutt, T. A., Silva, C., Solmaz, M., Solovov, V. N., Sorensen, P., Sumner, T. J., Szydagis, M., Taylor, D. J., Taylor, R., Taylor, W. C., Tennyson, B. P., Terman, P. A., Tiedt, D. R., To, W. H., Tvrznikova, L., Utku, U., Uvarov, S., Vacheret, A., Velan, V., Webb, R. C., White, J. T., Whitis, T. J., Witherell, M. S., Wolfs, F. L. H., Woodward, D., Xu, J., and Zhang, C.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The Large Underground Xenon (LUX) dark matter search was a 250-kg active mass dual-phase time projection chamber that operated by detecting light and ionization signals from particles incident on a xenon target. In December 2015, LUX reported a minimum 90% upper C.L. of 6e-46 cm^2 on the spin-independent WIMP-nucleon elastic scattering cross section based on a 1.4e4 kg*day exposure in its first science run. Tension between experiments and the absence of a definitive positive detection suggest it would be prudent to search for WIMPs outside the standard spin-independent/spin-dependent paradigm. Recent theoretical work has identified a complete basis of 14 independent effective field theory (EFT) operators to describe WIMP-nucleon interactions. In addition to spin-independent and spin-dependent nuclear responses, these operators can produce novel responses such as angular-momentum-dependent and spin-orbit couplings. Here we report on a search for all 14 of these EFT couplings with data from LUX's first science run. Limits are placed on each coupling as a function of WIMP mass., Comment: 11 pages, 6 figures

Published
2020
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