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Your search keyword '"Gangapshev, A."' showing total 48 results
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48 results on '"Gangapshev, A."'

1. Liquid argon light collection and veto modeling in GERDA Phase II

Author

GERDA Collaboration, Agostini, M., Alexander, A., Araujo, G. R., Bakalyarov, A. M., Balata, M., Barabanov, I., Baudis, L., Bauer, C., Belogurov, S., Bettini, A., Bezrukov, L., Biancacci, V., Bossio, E., Bothe, V., Brugnera, R., Caldwell, A., Calgaro, S., Cattadori, C., Chernogorov, A., Chiu, P-J., Comellato, T., D'Andrea, V., Demidova, E. V., Di Giacinto, A., Di Marco, N., Doroshkevich, E., Fischer, F., Fomina, M., Gangapshev, A., Garfagnini, A., Gooch, C., Grabmayr, P., Gurentsov, V., Gusev, K., Hakenmüller, J., Hemmer, S., Hofmann, W., Hult, M., Inzhechik, L. V., Csáthy, J. Janicskó, Jochum, J., Junker, M., Kazalov, V., Kermaïdic, Y., Khushbakht, H., Kihm, T., Kilgus, K., Kirpichnikov, I. V., Klimenko, A., Knöpfle, K. T., Kochetov, O., Kornoukhov, V. N., Krause, P., Kuzminov, V. V., Laubenstein, M., Lehnert, B., Lindner, M., Lippi, I., Lubashevskiy, A., Lubsandorzhiev, B., Lutter, G., Macolino, C., Majorovits, B., Maneschg, W., Manzanillas, L., Marshall, G., Miloradovic, M., Mingazheva, R., Misiaszek, M., Morella, M., Müller, Y., Nemchenok, I., Neuberger, M., Pandola, L., Pelczar, K., Pertoldi, L., Piseri, P., Pullia, A., Rauscher, L., Redchuk, M., Riboldi, S., Rumyantseva, N., Sada, C., Sailer, S., Salamida, F., Schönert, S., Schreiner, J., Schütt, M., Schütz, A-K., Schulz, O., Schwarz, M., Schwingenheuer, B., Selivanenko, O., Shevchik, E., Shirchenko, M., Shtembari, L., Simgen, H., Smolnikov, A., Stukov, D., Sullivan, S., Vasenko, A. A., Veresnikova, A., Vignoli, C., von Sturm, K., Wegmann, A., Wester, T., Wiesinger, C., Wojcik, M., Yanovich, E., Zatschler, B., Zhitnikov, I., Zhukov, S. V., Zinatulina, D., Zschocke, A., Zsigmond, A. J., Zuber, K., and Zuzel, G.

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

The ability to detect liquid argon scintillation light from within a densely packed high-purity germanium detector array allowed the GERDA experiment to reach an exceptionally low background rate in the search for neutrinoless double beta decay of $^{76}$Ge. Proper modeling of the light propagation throughout the experimental setup, from any origin in the liquid argon volume to its eventual detection by the novel light read-out system, provides insight into the rejection capability and is a necessary ingredient to obtain robust background predictions. In this paper, we present a model of the GERDA liquid argon veto, as obtained by Monte Carlo simulations and constrained by calibration data, and highlight its application for background decomposition.

Published
2022

2. Search for exotic physics in double-β decays with GERDA Phase II

Author

Agostini, M., Alexander, A., Araujo, G., Bakalyarov, A. M., Balata, M., Barabanov, I., Baudis, L., Bauer, C., Belogurov, S., Bettini, A., Bezrukov, L., Biancacci, V., Bossio, E., Bothe, V., Brugnera, R., Caldwell, A., Calgaro, S., Cattadori, C., Chernogorov, A., Comellato, T., D'Andrea, V., Demidova, E. V., Di Giacinto, A., Di Marco, N., Doroshkevich, E., Fischer, F., Fomina, M., Gangapshev, A., Garfagnini, A., Gooch, C., Grabmayr, P., Gurentsov, V., Gusev, K., Hakenmuller, J., Hemmer, S., Hofmann, W., Huang, J., Hult, M., Inzhechik, L. V., Janicsko Csathy, J., Jochum, J., Junker, M., Kazalov, V., Kermaidic, Y., Khushbakht, H., Kihm, T., Kilgus, K., Kirpichnikov, I. V., Klimenko, A., Knopfle, K. T., Kochetov, O., Kornoukhov, V. N., Krause, P., Kuzminov, V. V., Laubenstein, M., Lindner, M., Lippi, I., Lubashevskiy, A., Lubsandorzhiev, B., Lutter, G., Macolino, C., Majorovits, B., Maneschg, W., Manzanillas, L., Marshall, G., Miloradovic, M., Mingazheva, R., Misiaszek, M., Morella, M., Muller, Y., Nemchenok, I., Pandola, L., Pelczar, K., Pertoldi, L., Piseri, P., Pullia, A., Ransom, C., Rauscher, L., Redchuk, M., Riboldi, S., Rumyantseva, N., Sada, C., Sailer, S., Salamida, F., Schonert, S., Schreiner, J., Schutt, M., Schutz, A. -K., Schulz, O., Schwarz, M., Schwingenheuer, B., Selivanenko, O., Shevchik, E., Shirchenko, M., Shtembari, L., Simgen, H., Smolnikov, A., Stukov, D., Vasenko, A. A., Veresnikova, A., Vignoli, C., von Sturm, K., Wester, T., Wiesinger, C., Wojcik, M., Yanovich, E., Zatschler, B., Zhitnikov, I., Zhukov, S. V., Zinatulina, D., Zschocke, A., Zsigmond, A. J., Zuber, K., Zuzel, G., and The GERDA Collaboration

Subjects
High Energy Physics - Experiment (hep-ex), particle physics - cosmology connection, double beta decay, neutrino properties, particle physics - cosmology connection, GERDA - Abteilung Hinton, FOS: Physical sciences, double beta decay, Astronomy and Astrophysics, Nuclear Experiment (nucl-ex), paper, neutrino properties, ddc
Abstract

A search for Beyond the Standard Model double-β decay modes of 76Ge has been performed with data collected during the Phase II of the GERmanium Detector Array (Gerda) experiment, located at the Laboratori Nazionali del Gran Sasso of INFN (Italy). Improved limits on the decays involving Majorons have been obtained, compared to previous experiments with 76Ge, with half-life values on the order of 1023 yr. For the first time with 76Ge, limits on Lorentz invariance violation effects in double-β decay have been obtained. The isotropic coefficient åof (3), which embeds Lorentz violation in double-β decay, has been constrained at the order of 10-6 GeV. We also set the first experimental limits on the search for light exotic fermions in double-β decay, including sterile neutrinos.

Published
2022

3. Pulse shape analysis in Gerda Phase II

Author

The GERDA collaboration, Agostini, M., Araujo, G., Bakalyarov, A. M., Balata, M., Barabanov, I., Baudis, L., Bauer, C., Bellotti, E., Belogurov, S., Bettini, A., Bezrukov, L., Biancacci, V., Bossio, E., Bothe, V., Brudanin, V., Brugnera, R., Caldwell, A., Cattadori, C., Chernogorov, A., Comellato, T., D'Andrea, V., Demidova, E. V., Di Marco, N., Doroshkevich, E., Fischer, F., Fomina, M., Gangapshev, A., Garfagnini, A., Gooch, C., Grabmayr, P., Gurentsov, V., Gusev, K., Hakenmüller, J., Hemmer, S., Hiller, R., Hofmann, W., Huang, J., Hult, M., Inzhechik, L. V., Csáthy, J. Janicskó, Jochum, J., Junker, M., Kazalov, V., Kermaïdic, Y., Khushbakht, H., Kihm, T., Kilgus, K., Kirsch, A., Kirpichnikov, I. V., Klimenko, A., Knöpfle, K. T., Kochetov, O., Kornoukhov, V. N., Krause, P., Kuzminov, V. V., Laubenstein, M., Lazzaro, A., Lindner, M., Lippi, I., Lubashevskiy, A., Lubsandorzhiev, B., Lutter, G., Macolino, C., Majorovits, B., Maneschg, W., Manzanillas, L., Miloradovic, M., Mingazheva, R., Misiaszek, M., Müller, Y., Nemchenok, I., Panas, K., Pandola, L., Pelczar, K., Pertoldi, L., Piseri, P., Pullia, A., Ransom, C., Rauscher, L., Redchuk, M., Riboldi, S., Rumyantseva, N., Sada, C., Salamida, F., Schönert, S., Schreiner, J., Schütt, M., Schütz, A. -K., Schulz, O., Schwarz, M., Schwingenheuer, B., Selivanenko, O., Shevchik, E., Shirchenko, M., Shtembari, L., Simgen, H., Smolnikov, A., Stukov, D., Vasenko, A. A., Veresnikova, A., Vignoli, C., von Sturm, K., Wagner, V., Wester, T., Wiesinger, C., Wojcik, M., Yanovich, E., Zatschler, B., Zhitnikov, I., Zhukov, S. V., Zinatulina, D., Zschocke, A., Zsigmond, A. J., Zuber, K., and Zuzel, G.

Subjects
Technology, Physics - Instrumentation and Detectors, Physics and Astronomy (miscellaneous), FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), Nuclear Experiment (nucl-ex), Nuclear Experiment, Engineering (miscellaneous), ddc:600
Abstract

The GERmanium Detector Array (Gerda) collaboration searched for neutrinoless double-$$\beta $$ β decay in $$^{76}$$ 76 Ge using isotopically enriched high purity germanium detectors at the Laboratori Nazionali del Gran Sasso of INFN. After Phase I (2011–2013), the experiment benefited from several upgrades, including an additional active veto based on LAr instrumentation and a significant increase of mass by point-contact germanium detectors that improved the half-life sensitivity of Phase II (2015–2019) by an order of magnitude. At the core of the background mitigation strategy, the analysis of the time profile of individual pulses provides a powerful topological discrimination of signal-like and background-like events. Data from regular $$^{228}$$ 228 Th calibrations and physics data were both considered in the evaluation of the pulse shape discrimination performance. In this work, we describe the various methods applied to the data collected in Gerda Phase II corresponding to an exposure of 103.7 kg year. These methods suppress the background by a factor of about 5 in the region of interest around $$Q_{\beta \beta }= 2039$$ Q β β = 2039 keV, while preserving $$(81\pm 3)$$ ( 81 ± 3 ) % of the signal. In addition, an exhaustive list of parameters is provided which were used in the final data analysis.

Published
2021

4. $^{222}$Rn content variations at ground and underground conditions

Author

Etezov, R. A., Gavrilyuk, Yu. M., Gangapshev, A. M., Gezhaev, A. M., Kazalov, V. V., Khokonov, A. Kh., Kuzminov, V. V., Panasenko, S. I., and Ratkevich, S. S.

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

The activity of $^{222}$Rn and its daughter isotopes was measured in the air of several underground laboratories of the Baksan Neutrino Observatory at various distances from the entrance. The measurements were carried out with the help of the cylindrical ionionization air chamber. We found that the radon content in the ventilated airflow within the measurement accuracy does not depend on the distance travelled along the adit. In addition, we observed that the radon content increases abruptly in those locations where underground gases and water are released. As a result, we review various mechanisms of air enrichment with radon. We also outline our research methodology and present the results of our measurements of radon release from the rocky walls of the underground laboratory. Finally, we present the results of the measurements of the radon content of various ground and underground water sources., 11 pages, 9 figures, 1 table

Published
2021

5. Recent advancements of the experiment to search for $2K$-capture in $^{124}$Xe using a Large Low-background Proportional Counter

Author

Petrenko, O. D., Fedorets, I. D., Gangapshev, A. M., Garilyuk, Yu. M., Kazalov, V. V., Kuzminov, V. V., Panasenko, S. I., and Ratkevich, S. S.

Subjects
History, Physics - Instrumentation and Detectors, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), Nuclear Experiment (nucl-ex), Nuclear Experiment, Computer Science Applications, Education
Abstract

A new method for correcting the charge signal from the large proportional counter is proposed. The correction method makes it possible to take into account the loss of primary ionization electrons in the presence of weakly increasing micro impurities of electronegative gases during long-term measurements. It allows increasing the efficiency of the selection of useful events and thereby increasing the sensitivity to $2\nu2K$-decay in $^{124}$Xe at the level of $2\times10^{22}$ from over six years of measurements using a large proportional counter. Analysis of the calibration data, taking into account the new method for correcting the energy release in the detector, made it possible to register events from double $K$ photoionization by a single photon., 4 pages, 3 figures, to appear in the proceedings of the 17th International Conference on Topics in Astroparticle and Underground Physics (TAUP-2021) 26 August to 3 September 2021

Published
2021

6. LEGEND-1000 Preconceptual Design Report

Author

LEGEND Collaboration, Abgrall, N., Abt, I., Agostini, M., Alexander, A., Andreoiu, C., Araujo, G. R., Avignone, F. T., Bae, W., Bakalyarov, A., Balata, M., Bantel, M., Barabanov, I., Barabash, A. S., Barbeau, P. S., Barton, C. J., Barton, P. J., Baudis, L., Bauer, C., Bernieri, E., Bezrukov, L., Bhimani, K. H., Biancacci, V., Blalock, E., Bolozdynya, A., Borden, S., Bos, B., Bossio, E., Boston, A., Bothe, V., Bouabid, R., Boyd, S., Brugnera, R., Burlac, N., Busch, M., Caldwell, A., Caldwell, T. S., Carney, R., Cattadori, C., Chan, Y. -D., Chernogorov, A., Christofferson, C. D., Chu, P. -H., Clark, M., Cohen, T., Combs, D., Comellato, T., Cooper, R. J., Costa, I. A., D'Andrea, V., Detwiler, J. A., Di Giacinto, A., Di Marco, N., Dobson, J., Drobizhev, A., Durand, M. R., Edzards, F., Efremenko, Yu., Elliott, S. R., Engelhardt, A., Fajt, L., Faud, N., Febbraro, M. T., Ferella, F., Fields, D. E., Fischer, F., Fomina, M., Fox, H., Franchi, J., Gala, R., Galindo-Uribarri, A., Gangapshev, A., Garfagnini, A., Geraci, A., Gilbert, C., Gold, M., Gooch, C., Gradwohl, K. P., Green, M. P., Grinyer, G. F., Grobov, A., Gruszko, J., Guinn, I., Guiseppe, V. E., Gurentsov, V., Gurov, Y., Gusev, K., Hacket, B., Hagemann, F., Hakenm��eller, J., Haranczyk, M., Hauertmann, L., Haufe, C. R., Hayward, C., Heffron, B., Henkes, F., Henning, R., Aguilar, D. Hervas, Hinton, J., Hodak, R., Hoffmann, H., Hofmann, W., Hostiuc, A., Huang, J., Hult, M., Mirza, M. Ibrahim, Jochum, J., Jones, R., Judson, D., Junker, M., Kaizer, J., Kazalov, V., Kerma��dic, Y., Khushbakht, H., Kidd, M., Kihm, T., Kilgus, K., Kim, I., Klimenko, A., Kn��pfle, K. T., Kochetov, O., Konovalov, S. I., Kontul, I., Kool, K., Kormos, L. L., Kornoukhov, V. N., Korosec, M., Krause, P., Kuzminov, V. V., L��pez-Casta��o, J. M., Lang, K., Laubenstein, M., Le��n, E., Lehnert, B., Leonhardt, A., Li, A., Lindner, M., Lippi, I., Liu, X., Liu, J., Loomba, D., Lubashevskiy, A., Lubsandorzhiev, B., Lusardi, N., M��ller, Y., Macko, M., Macolino, C., Majorovits, B., Mamedov, F., Maneschg, W., Manzanillas, L., Marshall, G., Martin, R. D., Martin, E. L., Massarczyk, R., Mei, D., Meijer, S. J., Mertens, S., Misiaszek, M., Mondragon, E., Morella, M., Morgan, B., Mroz, T., Muenstermann, D., Nave, C. J., Nemchenok, I., Neuberger, M., Oli, T. K., Gann, G. Orebi, Othman, G., Palu��ova, V., Panth, R., Papp, L., Paudel, L. S., Pelczar, K., Perez, J. Perez, Pertoldi, L., Pettus, W., Piseri, P., Poon, A. W. P., Povinec, P., Pullia, A., Radford, D. C., Ramachers, Y. A., Ransom, C., Rauscher, L., Redchuk, M., Reine, A. L., Riboldi, S., Rielage, K., Rozov, S., Rukhadze, E., Rumyantseva, N., Runge, J., Ruof, N. W., Saakyan, R., Sailer, S., Salamanna, G., Salamida, F., Salvat, D. J., Sandukovsky, V., Sch��nert, S., Sch��ltz, A., Sch��tt, M., Schaper, D. C., Schreiner, J., Schulz, O., Schuster, M., Schwarz, M., Schwingenheuer, B., Selivanenko, O., Shaflee, M., Shevchik, E., Shirchenko, M., Shitov, Y., Simgen, H., Simkovic, F., Skorokhvatov, M., Slavickova, M., Smolek, K., Smolnikov, A., Solomon, J. A., Song, G., Starosta, K., Stekl, I., Stommel, M., Stukov, D., Sumathi, R. R., Sweigart, D. A., Szczepaniec, K., Taffarello, L., Tagnani, D., Tayloe, R., Tedeschi, D., Turqueti, M., Varner, R. L., Vasilyev, S., Veresnikova, A., Vetter, K., Vignoli, C., Vogl, C., von Sturm, K., Waters, D., Waters, J. C., Wei, W., Wiesinger, C., Wilkerson, J. F., Willers, M., Wiseman, C., Wojcik, M., Wu, V. H. -S., Xu, W., Yakushev, E., Ye, T., Yu, C. -H., Yumatov, V., Zaretski, N., Zeman, J., Zhitnikov, I., Zinatulina, D., Zschocke, A. -K., Zsigmond, A. J., Zuber, K., and Zuzel, G.

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

We propose the construction of LEGEND-1000, the ton-scale Large Enriched Germanium Experiment for Neutrinoless $\beta \beta$ Decay. This international experiment is designed to answer one of the highest priority questions in fundamental physics. It consists of 1000 kg of Ge detectors enriched to more than 90% in the $^{76}$Ge isotope operated in a liquid argon active shield at a deep underground laboratory. By combining the lowest background levels with the best energy resolution in the field, LEGEND-1000 will perform a quasi-background-free search and can make an unambiguous discovery of neutrinoless double-beta decay with just a handful of counts at the decay $Q$ value. The experiment is designed to probe this decay with a 99.7%-CL discovery sensitivity in the $^{76}$Ge half-life of $1.3\times10^{28}$ years, corresponding to an effective Majorana mass upper limit in the range of 9-21 meV, to cover the inverted-ordering neutrino mass scale with 10 yr of live time.

Published
2021

7. Characterization of inverted coaxial $^{76}$Ge detectors in GERDA for future double-$��$ decay experiments

Author

GERDA Collaboration, Agostini, M., Araujo, G. R., Bakalyarov, A. M., Balata, M., Barabanov, I., Baudis, L., Bauer, C., Bellotti, E., Belogurov, S., Bettini, A., Bezrukov, L., Biancacci, V., Bossio, E., Bothe, V., Brudanin, V., Brugnera, R., Caldwell, A., Cattadori, C., Chernogorov, A., Comellato, T., D'Andrea, V., Demidova, E. V., Di Marco, N., Doroshkevich, E., Fischer, F., Fomina, M., Gangapshev, A., Garfagnini, A., Gooch, C., Grabmayr, P., Gurentsov, V., Gusev, K., Hakenm��ller, J., Hemmer, S., Hofmann, W., Huang, J., Hult, M., Inzhechik, L. V., Cs��thy, J. Janicsk��, Jochum, J., Junker, M., Kazalov, V., Kerma��dic, Y., Khushbakht, H., Kihm, T., Kirpichnikov, I. V., Klimenko, A., Knei��l, R., Kn��pfle, K. T., Kochetov, O., Kornoukhov, V. N., Krause, P., Kuzminov, V. V., Laubenstein, M., Lindner, M., Lippi, I., Lubashevskiy, A., Lubsandorzhiev, B., Lutter, G., Macolino, C., Majorovits, B., Maneschg, W., Manzanillas, L., Miloradovic, M., Mingazheva, R., Misiaszek, M., Moseev, P., M��ller, Y., Nemchenok, I., Pandola, L., Pelczar, K., Pertoldi, L., Piseri, P., Pullia, A., Ransom, C., Rauscher, L., Riboldi, S., Rumyantseva, N., Sada, C., Salamida, F., Sch��nert, S., Schreiner, J., Sch��tt, M., Sch��tz, A. -K., Schulz, O., Schwarz, M., Schwingenheuer, B., Selivanenko, O., Shevchik, E., Shirchenko, M., Shtembari, L., Simgen, H., Smolnikov, A., Stukov, D., Vasenko, A. A., Veresnikova, A., Vignoli, C., von Sturm, K., Wester, T., Wiesinger, C., Wojcik, M., Yanovich, E., Zatschler, B., Zhitnikov, I., Zhukov, S. V., Zinatulina, D., Zschocke, A., Zsigmond, A. J., Zuber, K., and Zuzel, G.

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

Neutrinoless double-$��$ decay of $^{76}$Ge is searched for with germanium detectors where source and detector of the decay are identical. For the success of future experiments it is important to increase the mass of the detectors. We report here on the characterization and testing of five prototype detectors manufactured in inverted coaxial (IC) geometry from material enriched to 88% in $^{76}$Ge. IC detectors combine the large mass of the traditional semi-coaxial Ge detectors with the superior resolution and pulse shape discrimination power of point contact detectors which exhibited so far much lower mass. Their performance has been found to be satisfactory both when operated in vacuum cryostat and bare in liquid argon within the GERDA setup. The measured resolutions at the Q-value for double-$��$ decay of $^{76}$Ge (Q$_{����}$ = 2039 keV) are about 2.1 keV full width at half maximum in vacuum cryostat. After 18 months of operation within the ultra-low background environment of the GERmanium Detector Array (GERDA) experiment and an accumulated exposure of 8.5 kg$\cdot$yr, the background index after analysis cuts is measured to be $4.9^{+7.3}_{-3.4}\times 10^{-4}$ counts /(keV$\cdot$kg$\cdot$yr) around Q$_{����}$. This work confirms the feasibility of IC detectors for the next-generation experiment LEGEND., 13 pages, 12 figures, submitted to EPJC

Published
2021
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8. Calibration of the Gerda experiment

Author

T. Wester, A.A. Smolnikov, E. V. Demidova, J. Janicskó Csáthy, C. Cattadori, Anna Julia Zsigmond, Kai Zuber, A. V. Veresnikova, D. R. Zinatulina, A. Chernogorov, R. Hiller, T. Comellato, S. Belogurov, I. Zhitnikov, R. Mingazheva, B. Schwingenheuer, C. Bauer, P. Krause, Igor Nemchenok, Stefano Riboldi, L. Shtembari, Bela Majorovits, I. V. Kirpichnikov, Paolo Piseri, J. Huang, O.I. Kochetov, Mikael Hult, M. Misiaszek, M. Miloradovic, Laura Baudis, M. Fomina, S. Hemmer, J. Hakenmüller, G. R. Araujo, S. Schönert, A. M. Gangapshev, C. Vignoli, A. Garfagnini, M. Schütt, Werner Hofmann, O. Schulz, R. Kneißl, I. R. Barabanov, L. Manzanillas, C. Gooch, S. V. Zhukov, Josef Jochum, A. Lubashevskiy, Y. Kermaïdic, K. N. Gusev, V. D'Andrea, K. T. Knöpfle, Ivano Lippi, D. Stukov, Allen Caldwell, C. Wiesinger, V. I. Gurentsov, M. Balata, M. Shirchenko, R. Brugnera, L. B. Bezrukov, K. von Sturm, Bayarto Lubsandorzhiev, V. B. Brudanin, E. Bossio, A. A. Vasenko, E. Shevchik, V. V. Kazalov, V. V. Kuzminov, L. V. Inzhechik, A. Pullia, Franz Dieter Fischer, E. Doroshkevich, Matteo Agostini, F. Salamida, Cinzia Sada, B. Zatschler, M. M. Wojcik, W. Maneschg, E. A. Yanovich, E. Bellotti, M. Schwarz, C. Ransom, Hardy Simgen, G. Zuzel, L. Pertoldi, A.-K. Schütz, N. Di Marco, M. Junker, Manfred Lindner, O. Selivanenko, C. Macolino, M. Laubenstein, V. N. Kornoukhov, V. Bothe, K. Pelczar, Alessandro Bettini, Y. Müller, Guillaume Lutter, A. M. Bakalyarov, Jochen Schreiner, Th. Kihm, V. Biancacci, H. Khushbakht, P. Moseev, Luciano Pandola, L. Rauscher, A. A. Klimenko, A. Zschocke, N. Rumyantseva, P. Grabmayr, and GERDA Collaboration

Subjects
Physics - Instrumentation and Detectors, Physics and Astronomy (miscellaneous), Regular Article - Experimental Physics, Physics::Instrumentation and Detectors, chemistry.chemical_element, FOS: Physical sciences, Germanium, Electron, QC770-798, Astrophysics, 01 natural sciences, Standard Model, Nuclear physics, Nuclear and particle physics. Atomic energy. Radioactivity, 0103 physical sciences, Calibration, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Engineering (miscellaneous), Physics, 010308 nuclear & particles physics, Resolution (electron density), Detector, Instrumentation and Detectors (physics.ins-det), Semiconductor detector, QB460-466, chemistry, GERDA - Abteilung Hinton, High Energy Physics::Experiment, Energy (signal processing)
Abstract

The GERmanium Detector Array (GERDA) collaboration searched for neutrinoless double-$\beta$ decay in $^{76}$Ge with an array of about 40 high-purity isotopically-enriched germanium detectors. The experimental signature of the decay is a monoenergetic signal at Q$_{\beta\beta}$ = 2039.061(7)keV in the measured summed energy spectrum of the two emitted electrons. Both the energy reconstruction and resolution of the germanium detectors are crucial to separate a potential signal from various backgrounds, such as neutrino-accompanied double-$\beta$ decays allowed by the Standard Model. The energy resolution and stability were determined and monitored as a function of time using data from regular $^{228}$Th calibrations. In this work, we describe the calibration process and associated data analysis of the full GERDA dataset, tailored to preserve the excellent resolution of the individual germanium detectors when combining data over several years., Comment: 12 pages, 7 figures

Published
2021

9. Improving Calibration of the Large Low-Background Proportional Counter

Author

Petrenko, O. D., Gangapshev, A. M., Garilyuk, Yu. M., Kazalov, V. V., Kuzminov, V. V., Panasenko, S. I., Ratkevich, S. S., and Tekueva, D. A.

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

The study of low-yield effects requires not only good quality of the original data but also puts high requirements for their processing procedures to increase the efficiency of the selection of useful events. The exploiting of the large cylindrical proportional counter's electrostatic topology allows improving the extrapolation of information about the primary ionization of a multipoint event. Long-term calibration measurements with an external $^{109}$Cd-source allowed the development of a new method for analyzing the pulse shape from a sizeable proportional counter. Optimized analysis of the current's pulse shape from the electron cloud of primary ionization in the counter improved the resolution and energy calibration. As a result, the efficiency of selecting useful events was increased by 25\%., 6 pages, 6 figures, Prepared for the proceedings of The 5th International Conference on Particle Physics and Astrophysics (ICPPA-2020)

Published
2020

10. Annual variations of the $^{214}$Po, $^{213}$Po and $^{212}$Po half-life values

Author

A. M. Gezhaev, E. N. Alexeev, V. V. Kuzminov, O. D. Petrenko, V. Kazalov, S. I. Panasenko, S. S. Ratkevich, Yu. M. Gavrilyuk, and A. M. Gangapshev

Subjects
History, Animal science, Astrophysics - Solar and Stellar Astrophysics, Half-life, Environmental science, FOS: Physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment, Solar and Stellar Astrophysics (astro-ph.SR), Computer Science Applications, Education
Abstract

Results of a comparative analysis of the $^{214}$Po ($T_{1/2}= 163.47\pm0.03$ $\mu$s), $^{213}$Po ($T_{1/2}=3.705 \pm 0.001$ $\mu$s) and $^{212}$Po ($T_{1/2}=294.09\pm0.07$ ns) half-life annular variation parameters are presented. It is shown that two independent sequential sets of the $^{214}$Po $\tau$-values $(\tau\equiv T_{1/2})$ obtained in the spaced laboratories can be described by sinusoidal functions. The sinusoid curve with amplitude $A=(5.0 \pm1.5) \cdot 10^{-4}$, period $\omega=(365\pm 8)$ days, and phase $\phi=(170 \pm 7)$ days approximates the set of $^{214}$Po $\tau$ values obtained at BNO INR RAS during the $\sim$973 days starting on January 4, 2012. The function approximates a set of $\tau$-values with a time duration of $\sim1460$ days obtained at the KhNU has an amplitude $A=(4.9\pm1.8)\cdot10^{-4}$, a period $\omega= (377\pm13)$ days and a phase $\phi=(77\pm10)$ days. The $^{213}$Po $\tau$-value set with a time duration of $\sim1700$ days can be described by a sinusoidal function with an amplitude $A=(3.9\pm1.2)\cdot10^{-4}$, a period $\omega= (370\pm13)$ days and a phase $\phi=(130\pm9)$ days. The $^{212}$Po $\tau$-value set with a time duration of $\sim670$ days can be described by a sinusoidal function with an amplitude $A=(7.5\pm1.6)\cdot10^{-4}$, a period $\omega= (375\pm13)$ days and a phase $\phi=(40\pm10)$ days., Comment: 6 pages, 5 figures, Prepared for the proceedings of The 5th International Conference on Particle Physics and Astrophysics (ICPPA-2020)

Published
2020
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11. Final Results of GERDA on the Search for Neutrinoless Double-$��$ Decay

Author

GERDA Collaboration, Agostini, M., Araujo, G. R., Bakalyarov, A. M., Balata, M., Barabanov, I., Baudis, L., Bauer, C., Bellotti, E., Belogurov, S., Bettini, A., Bezrukov, L., Biancacci, V., Borowicz, D., Bossio, E., Bothe, V., Brudanin, V., Brugnera, R., Caldwell, A., Cattadori, C., Chernogorov, A., Comellato, T., D'Andrea, V., Demidova, E. V., Di Marco, N., Doroshkevich, E., Fischer, F., Fomina, M., Gangapshev, A., Garfagnini, A., Gooch, C., Grabmayr, P., Gurentsov, V., Gusev, K., Hakenm��ller, J., Hemmer, S., Hiller, R., Hofmann, W., Huang, J., Hult, M., Inzhechik, L. V., Cs��thy, J. Janicsk��, Jochum, J., Junker, M., Kazalov, V., Kerma��dic, Y., Khushbakht, H., Kihm, T., Kirpichnikov, I. V., Klimenko, A., Knei��l, R., Kn��pfle, K. T., Kochetov, O., Kornoukhov, V. N., Krause, P., Kuzminov, V. V., Laubenstein, M., Lazzaro, A., Lindner, M., Lippi, I., Lubashevskiy, A., Lubsandorzhiev, B., Lutter, G., Macolino, C., Majorovits, B., Maneschg, W., Manzanillas, L., Miloradovic, M., Mingazheva, R., Misiaszek, M., Moseev, P., M��ller, Y., Nemchenok, I., Panas, K., Pandola, L., Pelczar, K., Pertoldi, L., Piseri, P., Pullia, A., Ransom, C., Rauscher, L., Riboldi, S., Rumyantseva, N., Sada, C., Salamida, F., Sch��nert, S., Schreiner, J., Sch��tt, M., Sch��tz, A. -K., Schulz, O., Schwarz, M., Schwingenheuer, B., Selivanenko, O., Shevchik, E., Shirchenko, M., Shtembari, L., Simgen, H., Smolnikov, A., Stukov, D., Vasenko, A. A., Veresnikova, A., Vignoli, C., von Sturm, K., Wester, T., Wiesinger, C., Wojcik, M., Yanovich, E., Zatschler, B., Zhitnikov, I., Zhukov, S. V., Zinatulina, D., Zschocke, A., Zsigmond, A. J., Zuber, K., and Zuzel, G.

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

The GERmanium Detector Array (GERDA) experiment searched for the lepton-number-violating neutrinoless double-$��$ ($0������$) decay of $^{76}$Ge, whose discovery would have far-reaching implications in cosmology and particle physics. By operating bare germanium diodes, enriched in $^{76}$Ge, in an active liquid argon shield, GERDA achieved an unprecedently low background index of $5.2\times10^{-4}$ counts/(keV$\cdot$kg$\cdot$yr) in the signal region and met the design goal to collect an exposure of 100 kg$\cdot$yr in a background-free regime. When combined with the result of Phase I, no signal is observed after 127.2 kg$\cdot$yr of total exposure. A limit on the half-life of $0������$ decay in $^{76}$Ge is set at $T_{1/2}>1.8\times10^{26}$ yr at 90% C.L., which coincides with the sensitivity assuming no signal., 7 pages, 3 figures, submitted to Physical Review Letters

Published
2020
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12. The first search for bosonic super-WIMPs with masses up to 1 MeV/c$^2$ with GERDA

Author

GERDA collaboration, Agostini, M., Bakalyarov, A. M., Balata, M., Barabanov, I., Baudis, L., Bauer, C., Bellotti, E., Belogurov, S., Bettini, A., Bezrukov, L., Borowicz, D., Bossio, E., Bothe, V., Brudanin, V., Brugnera, R., Caldwell, A., Cattadori, C., Chernogorov, A., Comellato, T., D'Andrea, V., Demidova, E. V., Di Marco, N., Doroshkevich, E., Egorov, V., Fischer, F., Fomina, M., Gangapshev, A., Garfagnini, A., Gooch, C., Grabmayr, P., Gurentsov, V., Gusev, K., Hakenmüller, J., Hemmer, S., Hiller, R., Hofmann, W., Hult, M., Inzhechik, L. V., Csáthy, J. Janicskó, Jochum, J., Junker, M., Kazalov, V., Kermaïdic, Y., Khushbakht, H., Kihm, T., Kirpichnikov, I. V., Klimenko, A., Kneißl, R., Knöpfle, K. T., Kochetov, O., Kornoukhov, V. N., Krause, P., Kuzminov, V. V., Laubenstein, M., Lazzaro, A., Lindner, M., Lippi, I., Lubashevskiy, A., Lubsandorzhiev, B., Lutter, G., Macolino, C., Majorovits, B., Maneschg, W., Miloradovic, M., Mingazheva, R., Misiaszek, M., Moseev, P., Nemchenok, I., Panas, K., Pandola, L., Pelczar, K., Pertoldi, L., Piseri, P., Pullia, A., Ransom, C., Rauscher, L., Riboldi, S., Rumyantseva, N., Sada, C., Salamida, F., Schönert, S., Schreiner, J., Schütt, M., Schütz, A-K., Schulz, O., Schwarz, M., Schwingenheuer, B., Selivanenko, O., Shevchik, E., Shirchenko, M., Simgen, H., Smolnikov, A., Stukov, D., Vasenko, A. A., Veresnikova, A., Vignoli, C., von Sturm, K., Wester, T., Wiesinger, C., Wojcik, M., Yanovich, E., Zatschler, B., Zhitnikov, I., Zhukov, S. V., Zinatulina, D., Zschocke, A., Zsigmond, A. J., and Zuzel, K. Zuber G.

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

We present the first search for bosonic super-WIMPs as keV-scale dark matter candidates performed with the GERDA experiment. GERDA is a neutrinoless double-beta decay experiment which operates high-purity germanium detectors enriched in $^{76}$Ge in an ultra-low background environment at the Laboratori Nazionali del Gran Sasso (LNGS) of INFN in Italy. Searches were performed for pseudoscalar and vector particles in the mass region from 60 keV/c$^2$ to 1 MeV/c$^2$. No evidence for a dark matter signal was observed, and the most stringent constraints on the couplings of super-WIMPs with masses above 120 keV/c$^2$ have been set. As an example, at a mass of 150 keV/c$^2$ the most stringent direct limits on the dimensionless couplings of axion-like particles and dark photons to electrons of $g_{ae} < 3 \cdot 10^{-12}$ and ${\alpha'}/{\alpha} < 6.5 \cdot 10^{-24}$ at 90% credible interval, respectively, were obtained., Comment: 6 pages, 3 figures, submitted to Physical Review Letters, added list of authors, updated ref. [21]

Published
2020
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13. Modeling of GERDA Phase II data

Author

A. Domula, M. Schwarz, Laura Baudis, C. Wiesinger, Paolo Piseri, M. Shirchenko, A. Lazzaro, E. Bossio, I. V. Kirpichnikov, Alessandro Bettini, D. R. Zinatulina, M. Miloradovic, E. V. Demidova, A. V. Veresnikova, A. Chernogorov, R. Hiller, R. Kneißl, S. Belogurov, V. D'Andrea, Stefano Riboldi, V.B. Brudanin, C. Ransom, Igor Nemchenok, M. Schütt, M. Misiaszek, Cinzia Sada, B. Zatschler, Bela Majorovits, C. Macolino, Hardy Simgen, W. Maneschg, E. A. Yanovich, P. Moseev, Luciano Pandola, A. A. Klimenko, C. Vignoli, R. Brugnera, Mikael Hult, D. Borowicz, K. N. Gusev, Jochen Schreiner, L. Pertoldi, F. Fischer, Josef Jochum, N. Rumyantseva, V. V. Kuzminov, Matteo Agostini, V. I. Gurentsov, S. Hemmer, Y. Kermaïdic, J. Janicskó Csáthy, Stefan Schönert, E. Doroshkevich, Bayarto Lubsandorzhiev, L. V. Inzhechik, Ivano Lippi, Manfred Lindner, E. Bellotti, T. Wester, A.A. Smolnikov, K. Panas, I. Zhitnikov, V. Bothe, C. Cattadori, Anna Julia Zsigmond, Kai Zuber, A. Zschocke, L. B. Bezrukov, E. Shevchik, A.-K. Schütz, Marcin Wójcik, V. N. Kornoukhov, M. Fomina, P. Grabmayr, K. Pelczar, N. Di Marco, O.I. Kochetov, Guillaume Lutter, A. M. Bakalyarov, I. R. Barabanov, A. M. Gangapshev, C. Gooch, S. V. Zhukov, Thomas Kihm, O. Selivanenko, R. Mingazheva, B. Schwingenheuer, M. Junker, Oliver Schulz, Alberto Pullia, V. G. Egorov, M. Balata, A. Garfagnini, K. T. Knöpfle, T. Comellato, L. Vanhoefer, Matthias Laubenstein, G. Zuzel, V. V. Kazalov, P. Krause, A. A. Vasenko, Christian Bauer, A. Lubashevskiy, J. Hakenmüller, D. Stukov, Werner Hofmann, F. Salamida, Allen Caldwell, and K. von Sturm

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Physics - Instrumentation and Detectors, 010308 nuclear & particles physics, Spectrum (functional analysis), Detector, Phase (waves), FOS: Physical sciences, Order (ring theory), Instrumentation and Detectors (physics.ins-det), 01 natural sciences, Semiconductor detector, ddc, Region of interest, 0103 physical sciences, Dark Matter and Double Beta Decay (experiments), lcsh:QC770-798, lcsh:Nuclear and particle physics. Atomic energy. Radioactivity, DOUBLE-BETA DECAY, Sensitivity (control systems), Nuclear Experiment (nucl-ex), Neutrino, 010306 general physics, Nuclear Experiment
Abstract

The GERmanium Detector Array (Gerda) experiment at the Gran Sasso underground laboratory (LNGS) of INFN is searching for neutrinoless double-beta (0νββ) decay of 76Ge. The technological challenge of Gerda is to operate in a “background-free” regime in the region of interest (ROI) after analysis cuts for the full 100 kg·yr target exposure of the experiment. A careful modeling and decomposition of the full-range energy spectrum is essential to predict the shape and composition of events in the ROI around Qββ for the 0νββ search, to extract a precise measurement of the half-life of the double-beta decay mode with neutrinos (2νββ) and in order to identify the location of residual impurities. The latter will permit future experiments to build strategies in order to further lower the background and achieve even better sensitivities. In this article the background decomposition prior to analysis cuts is presented for Gerda Phase II. The background model fit yields a flat spectrum in the ROI with a background index (BI) of $$ {16.04}_{-0.85}^{+0.78}\cdotp {10}^{-3} $$ 16.04 − 0.85 + 0.78 · 10 − 3 cts/(keV·kg·yr) for the enriched BEGe data set and $$ {14.68}_{-0.52}^{+0.47}\cdotp {10}^{-3} $$ 14.68 − 0.52 + 0.47 · 10 − 3 cts/(keV·kg·yr) for the enriched coaxial data set. These values are similar to the one of Phase I despite a much larger number of detectors and hence radioactive hardware components.

Published
2019

14. Results of a search for daily and annual variations of the 214Po half-life at the two year observation period

Author

S. S. Ratkevich, V. V. Kuzminov, E.N. Alexeyev, A. M. Gangapshev, S. I. Panasenko, V. V. Kazalov, and Yu. M. Gavrilyuk

Subjects
Physics, Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, 010308 nuclear & particles physics, Observation period, FOS: Physical sciences, Total measurement, Half-life, Instrumentation and Detectors (physics.ins-det), Time step, Geodesy, 01 natural sciences, Amplitude, Astrophysics - Solar and Stellar Astrophysics, 0103 physical sciences, Annual variation, Nuclear Experiment (nucl-ex), Variation (astronomy), Nuclear Experiment, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

The brief description of installation TAU-2 intended for long-term monitoring of the half-life value $\tau$ ($\tau_{1/2}$) of the $^{214}$Po is presented. The methods of measurement and processing of collected data are reported. The results of analysis of time series values $\tau$ with different time step are presented. Total of measurement time was equal to 590 days. Averaged value of the $^{214}$Po half-life was obtained $\tau=163.46\pm0.04$ $\mu$s. The annual variation with an amplitude $A=(8.9\pm2.3)\cdot10^{-4}$, solar-daily variation with an amplitude $A_{So}=(7.5\pm1.2)\cdot10^{-4}$, lunar-daily variation with an amplitude $A_L=(6.9\pm2.0)\cdot10^{-4}$ and sidereal-daily variation with an amplitude $A_S=(7.2\pm1.2)\cdot10^{-4}$ were found in a series of $\tau$ values. The maximal values of amplitude are observed at the moments when the projections of the installation Earth location velocity vectors toward the source of possible variation achieve its maximal magnitudes., Comment: Talk at The International Workshop on Prospects of Particle Physics: "Neutrino Physics and Astrophysics" February 1 - Ferbuary 8, 2015, Valday,Russia, 7 pages, 12 figure (to be published in PEPAN)

Published
2016

15. Probing Majorana neutrinos with double-$��$ decay

Author

GERDA Collaboration, Agostini, M., Bakalyarov, A. M., Balata, M., Barabanov, I., Baudis, L., Bauer, C., Bellotti, E., Belogurov, S., Bettini, A., Bezrukov, L., Borowicz, D., Brudanin, V., Brugnera, R., Caldwell, A., Cattadori, C., Chernogorov, A., Comellato, T., D'Andrea, V., Demidova, E. V., Di Marco, N., Domula, A., Doroshkevich, E., Egorov, V., Falkenstein, R., Fomina, M., Gangapshev, A., Garfagnini, A., Giordano, M., Grabmayr, P., Gurentsov, V., Gusev, K., Hakenm��ller, J., Hegai, A., Heisel, M., Hemmer, S., Hiller, R., Hofmann, W., Hult, M., Inzhechik, L. V., Cs��thy, J. Janicsk��, Jochum, J., Junker, M., Kazalov, V., Kerma��dic, Y., Kihm, T., Kirpichnikov, I. V., Kirsch, A., Kish, A., Klimenko, A., Knei��l, R., Kn��pfle, K. T., Kochetov, O., Kornoukhov, V. N., Krause, P., Kuzminov, V. V., Laubenstein, M., Lazzaro, A., Lindner, M., Lippi, I., Lubashevskiy, A., Lubsandorzhiev, B., Lutter, G., Macolino, C., Majorovits, B., Maneschg, W., Miloradovic, M., Mingazheva, R., Misiaszek, M., Moseev, P., Nemchenok, I., Panas, K., Pandola, L., Pelczar, K., Pertoldi, L., Piseri, P., Pullia, A., Ransom, C., Riboldi, S., Rumyantseva, N., Sada, C., Sala, E., Salamida, F., Schmitt, C., Schneider, B., Sch��nert, S., Sch��tz, A. -K., Schulz, O., Schwingenheuer, B., Schwarz, M., Selivanenko, O., Shevchik, E., Shirchenko, M., Simgen, H., Smolnikov, A., Stanco, L., Stukov, D., Vanhoefer, L., Vasenko, A. A., Veresnikova, A., von Sturm, K., Wagner, V., Wegmann, A., Wester, T., Wiesinger, C., Wojcik, M., Yanovich, E., Zhitnikov, I., Zhukov, S. V., Zinatulina, D., Zschocke, A., Zsigmond, A. J., Zuber, K., and Zuzel, G.

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

A discovery that neutrinos are not the usual Dirac but Majorana fermions, i.e. identical to their antiparticles, would be a manifestation of new physics with profound implications for particle physics and cosmology. Majorana neutrinos would generate neutrinoless double-$��$ ($0������$) decay, a matter-creating process without the balancing emission of antimatter. So far, 0$������$ decay has eluded detection. The GERDA collaboration searches for the $0������$ decay of $^{76}$Ge by operating bare germanium detectors in an active liquid argon shield. With a total exposure of 82.4 kg$\cdot$yr, we observe no signal and derive a lower half-life limit of T$_{1/2}$ > 0.9$\cdot$10$^{26}$ yr (90% C.L.). Our T$_{1/2}$ sensitivity assuming no signal is 1.1$\cdot$10$^{26}$ yr. Combining the latter with those from other $0������$ decay searches yields a sensitivity to the effective Majorana neutrino mass of 0.07 - 0.16 eV, with corresponding sensitivities to the absolute mass scale in $��$ decay of 0.15 - 0.44 eV, and to the cosmological relevant sum of neutrino masses of 0.46 - 1.3 eV., Authors' main+supplementary text: 13+28 pages, 3+12 figures, 1+7 tables. Definite version to be published in Science

Published
2019
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16. Searching for neutrinoless double beta decay with GERDA

Author

S. Hemmer, V. N. Kornoukhov, Matthias Laubenstein, K. Pelczar, V. G. Egorov, K. T. Knöpfle, R. Brugnera, M. Balata, A. A. Vasenko, Guillaume Lutter, T. Wester, A. M. Bakalyarov, V. I. Lebedev, A.A. Smolnikov, A. Lazzaro, V. V. Kuzminov, Matteo Agostini, C. Wiesinger, L. Vanhoefer, Thomas Kihm, B. Schneider, Anna Julia Zsigmond, M. Shirchenko, E. Doroshkevich, Manfred Lindner, L. B. Bezrukov, Oliver Schulz, Kai Zuber, C. Macolino, L. Stanco, V. V. Kazalov, E. Shevchik, O.I. Kochetov, G. Zuzel, R. Falkenstein, H. V. Kirpichnikov, Jochen Schreiner, Alberto Pullia, A. Garfagnini, D. R. Zinatulina, O. Selivanenko, V.B. Brudanin, C. Ransom, J. Janicsko, A.-K. Schütz, Hardy Simgen, Werner Hofmann, Allen Caldwell, M. Miloradovic, V. I. Gurentsov, K. N. Gusev, A. Hegai, K. Panas, T. Bode, A. Kish, A. M. Gangapshev, Marcin Wójcik, N. Di Marco, R. Mingazheva, Christian Bauer, A. Lubashevskiy, A. Domula, R. Kneiβl, Cinzia Sada, M. Junker, J. Hakenmüller, P. Grabmayr, B. Schwingenheuer, K. von Sturm, Mikael Hult, R. Hiller, Stefano Riboldi, E. Bellotti, Bayarto Lubsandorzhiev, Stefan Schönert, C. Gooch, P. Moseev, Luciano Pandola, V. Wagner, I. Zhitnikov, I. R. Barabanov, Laura Baudis, M. Misiaszek, A. A. Klimenko, M. Heisel, N. Rumyantseva, F. Salamida, S. V. Zhukov, Alessandro Bettini, B. Cattadori, A. Kirsch, Y. Kermaïdic, V. D'Andrea, Ivano Lippi, L. V. Inzhechik, W. Maneschg, E. A. Yanovich, C. Schmitt, A. V. Veresnikova, A. Chernogorov, J. Jochum Csáthy, A. Wegmann, Igor Nemchenok, Bela Majorovits, E. V. Demidova, and S. Belogurov

Subjects
Paper, Physics, History, Particle physics, Physics - Instrumentation and Detectors, Double beta decay, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), Nuclear Experiment (nucl-ex), Nuclear Experiment, ddc, Computer Science Applications, Education
Abstract

The GERmanium Detector Array (GERDA) experiment located at the INFN Gran Sasso Laboratory (Italy), is looking for the neutrinoless double beta decay of Ge76, by using high-purity germanium detectors made from isotopically enriched material. The combination of the novel experimental design, the careful material selection for radio-purity and the active/passive shielding techniques result in a very low residual background at the Q-value of the decay, about 1e-3 counts/(keV kg yr). This makes GERDA the first experiment in the field to be background-free for the complete design exposure of 100 kg yr. A search for neutrinoless double beta decay was performed with a total exposure of 47.7 kg yr: 23.2 kg yr come from the second phase (Phase II) of the experiment, in which the background is reduced by about a factor of ten with respect to the previous phase. The analysis presented in this paper includes 12.4 kg yr of new Phase II data. No evidence for a possible signal is found: the lower limit for the half-life of Ge76 is 8.0e25 yr at 90% CL. The experimental median sensitivity is 5.8e25 yr. The experiment is currently taking data. As it is running in a background-free regime, its sensitivity grows linearly with exposure and it is expected to surpass 1e26 yr within 2018., 8 pages, to appear in the proceedings of TAUP2017

Published
2020

17. Search for Variations of Po-213 Half-Life

Author

Alexeyev, E. N., Gavrilyuk, Yu. M., Gangapshev, A. M., Gezhaev, A. M., Kazalov, V. V., Kuzminov, V. V., Panasenko, S. I., and Ratkevich, S. S.

Subjects
FOS: Physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract

A device with the parent $^{229}$Th source was constructed to search for variations of the daughter $^{213}$Po half-life ($T_{1/2} = 4.2$ $\mu$s). A solar-daily variation with amplitude $A_{So}=(5.3 \pm 1.1) \times 10^{-4}$, a lunar-daily variation with amplitude $A_L = (4.8 \pm 2.1) \times 10^{-4}$, and a sidereal-daily variation with amplitude $A_S = (4.2 \pm 1.7) \times 10^{-4}$ were found upon proceeding the data series over a 622-day interval (from July 2015 to March 2017). The $^{213}$Po half-life mean value is found to be $T_{1/2} = 3.705 \pm 0.001$ $\mu$s. The obtained half-life is in good agreement with some of the literature values obtained with great accuracy., Comment: 6 pages, 9 figures; to be published in PEPAN

Published
2018

18. 2K(2��)-Capture in Xe-124: Results of Data Processing for an Exposure of 37.7 kg x day

Author

Gavriljuk, Yu. M., Gangapshev, A. M., Kazalov, V. V., Kuzminov, V. V., Panasenko, S. I., Ratkevich, S. S., and Tekueva, D. A.

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

The results of the experimental search for two-neutrino $2K$-capture in $^{124}$Xe with a large copper proportional counter obtained by processing the data for an exposure of 37.7 kg$\times$day are presented. The experimental setup is located at the Underground Low-Background Laboratory of the Baksan Neutrino Observatory at a depth of 4900 m w.e. The combination of methods of selection of useful signals with a unique set of characteristics and the event topology taken into account allowed us to suppress the background in the energy region of interest. A new half-life limit for $2K(2��)$-capture in $^{124}$Xe was determined: T$_{1/2}\geq7.7\cdot10^{21}$ yrs (90\% C.L.)., 5 pages, 4 figures; to be published in PEPAN

Published
2018
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19. Mitigation of ^{42}Ar/^{42}K background for the GERDA phase II experiment

Author

Lubashevskiy, A., Agostini, M., Budjáš, D., Gangapshev, A., Gusev, K., Heisel, M., Klimenko, A., Lazzaro, A., Lehnert, B., Pelczar, K., Schönert, S., Smolnikov, A., Walter, M., and Zuzel, G.

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

Background coming from the $^{42}$Ar decay chain is considered to be one of the most relevant for the GERDA experiment, which aims to search of the neutrinoless double beta decay of $^{76}$Ge. The sensitivity strongly relies on the absence of background around the Q-value of the decay. Background coming from $^{42}$K, a progeny of $^{42}$Ar, can contribute to that background via electrons from the continuous spectrum with an endpoint of 3.5 MeV. Research and development on the suppression methods targeting this source of background were performed at the low-background test facility LArGe. It was demonstrated that by reducing $^{42}$K ion collection on the surfaces of the broad energy germanium detectors in combination with pulse shape discrimination techniques and an argon scintillation veto, it is possible to suppress the $^{42}$K background by three orders of magnitude. This is sufficient for Phase II of the GERDA experiment.

Published
2018

20. Recent results of search for solar axions using resonant absorption by $^{83}$Kr nuclei

Author

V. V. Kuzminov, A. V. Derbin, S. P. Yakimenko, V. Kazalov, Yu. M. Gavrilyuk, E. V. Unzhakov, V. N. Muratova, S. S. Ratkevich, I. S. Drachnev, A. M. Gangapshev, V. V. Kobychev, D. A. Tekueva, and S I Panashenko

Subjects
Physics, History, Particle physics, Isovector, Physics::Instrumentation and Detectors, Isoscalar, Hadron, High Energy Physics::Phenomenology, Nuclear Theory, Proportional counter, FOS: Physical sciences, Computer Science Applications, Education, High Energy Physics - Experiment, High Energy Physics - Phenomenology, High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology (hep-ph), Observatory, Limit (mathematics), Neutrino, Nuclear Experiment (nucl-ex), Axion, Nuclear Experiment
Abstract

Derbin A.V. "Recent results of search for solar axions using resonant absorption by $^{83}$Kr nuclei" in Proceedings of the 13th "Patras" Workshop on Axions, WIMPs and WISPs, PATRAS 2017 / Maroudas, Marios (eds.), Verlag Deutsches Elektronen-Synchrotron : 2018 ; Patras 2017 : 13th Patras Workshop on Axions, WIMPs and WISPs, 2017-05-15 - 2017-05-19, Thessaloniki 13th Patras Workshop on Axions, WIMPs and WISPs, Patras 2017, Thessaloniki, Greece, 15 May 2017 - 19 May 2017; Hamburg : Verlag Deutsches Elektronen-Synchrotron, DESY-PROC, 79-82 (2018). doi:10.3204/DESY-PROC-2017-02/muratova_valentina, A search for resonant absorption of the solar axion by $^{83}\rm{Kr}$ nuclei was performed using the proportional counter installed inside the low-background setup at the Baksan Neutrino Observatory. The obtained model independent upper limit on the combination of isoscalar and isovector axion-nucleon couplings $|g_3-g_0|\leq 8.4\times 10^{-7}$ allowed us to set the new upper limit on the hadronic axion mass of $m_{A}\leq 65$ eV (95\% C.L.) with the generally accepted values $S$=0.5 and $z$=0.56., Published by Verlag Deutsches Elektronen-Synchrotron, Hamburg

Published
2018

21. Upgrade for Phase II of the GERDA Experiment

Author

GERDA Collaboration, M. Agostini, A. M. Bakalyarov, M. Balata, I. Barabanov, L. Baudis, C. Bauer, E. Bellotti, S. Belogurov, S. T. Belyaev, G. Benato, A. Bettini, L. Bezrukov, T. Bode, D. Borowicz, V. Brudanin, R. Brugnera, A. Caldwell, C. Cattadori, A. Chernogorov, V. D’Andrea, E. V. Demidova, N. Di Marco, A. Domula, E. Doroshkevich, V. Egorov, R. Falkenstein, N. Frodyma, A. Gangapshev, A. Garfagnini, P. Grabmayr, V. Gurentsov, K. Gusev, J. Hakenmüller, A. Hegai, M. Heisel, S. Hemmer, R. Hiller, W. Hofmann, M. Hult, L. V. Inzhechik, L. Ioannucci, J. Janicskó Csáthy, J. Jochum, M. Junker, V. Kazalov, Y. Kermaïdic, T. Kihm, I. V. Kirpichnikov, A. Kirsch, A. Kish, A. Klimenko, R. Kneißl, K. T. Knöpfle, O. Kochetov, V. N. Kornoukhov, V. V. Kuzminov, M. Laubenstein, A. Lazzaro, V. I. Lebedev, B. Lehnert, M. Lindner, I. Lippi, A. Lubashevskiy, B. Lubsandorzhiev, G. Lutter, C. Macolino, B. Majorovits, W. Maneschg, E. Medinaceli, M. Miloradovic, R. Mingazheva, M. Misiaszek, P. Moseev, I. Nemchenok, S. Nisi, K. Panas, L. Pandola, K. Pelczar, A. Pullia, C. Ransom, S. Riboldi, N. Rumyantseva, C. Sada, F. Salamida, M. Salathe, C. Schmitt, B. Schneider, S. Schönert, J. Schreiner, A-K. Schütz, O. Schulz, B. Schwingenheuer, O. Selivanenko, E. Shevchik, M. Shirchenko, H. Simgen, A. Smolnikov, L. Stanco, L. Vanhoefer, A. A. Vasenko, A. Veresnikova, K. von Sturm, V. Wagner, A. Wegmann, T. Wester, C. Wiesinger, M. Wojcik, E. Yanovich, I. Zhitnikov, S. V. Zhukov, D. Zinatulina, A. J. Zsigmond, K. Zuber, and G. Zuzel

Subjects
Physics - Instrumentation and Detectors, Physics and Astronomy (miscellaneous), Phase (waves), FOS: Physical sciences, lcsh:Astrophysics, VETO, nucl-ex, 01 natural sciences, Nuclear physics, DEPENDENCE, Double beta decay, LIQUID ARGON, lcsh:QB460-466, 0103 physical sciences, lcsh:Nuclear and particle physics. Atomic energy. Radioactivity, Sensitivity (control systems), Nuclear Experiment (nucl-ex), BETA-DECAY, 010306 general physics, Engineering (miscellaneous), Nuclear Experiment, physics.ins-det, Physics, 010308 nuclear & particles physics, Detector, Instrumentation and Detectors (physics.ins-det), NEUTRINOS, Upgrade, GE-76, lcsh:QC770-798, SCINTILLATION, Data release, Order of magnitude
Abstract

The GERDA collaboration is performing a sensitive search for neutrinoless double beta decay of $^{76}$Ge at the INFN Laboratori Nazionali del Gran Sasso, Italy. The upgrade of the GERDA experiment from Phase I to Phase II has been concluded in December 2015. The first Phase II data release shows that the goal to suppress the background by one order of magnitude compared to Phase I has been achieved. GERDA is thus the first experiment that will remain background-free up to its design exposure (100 kg yr). It will reach thereby a half-life sensitivity of more than 10$^{26}$ yr within 3 years of data collection. This paper describes in detail the modifications and improvements of the experimental setup for Phase II and discusses the performance of individual detector components., 31 pages, 34 figures

Published
2017

22. First result of the experimental search for the 9.4 keV solar axion reactions with 83Kr in the copper proportional counter

Author

V. V. Kazalov, E. V. Unzhakov, S. I. Panasenko, S. S. Ratkevich, H. J. Kim, A. M. Gangapshev, S. P. Yakimenko, V. V. Kobychev, D. A. Semenov, A. V. Derbin, Yu. M. Gavrilyuk, V. V. Kuzminov, Luqman Ali, Y. D. Kim, D. A. Tekueva, and V. N. Muratova

Subjects
Physics, Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, Krypton, FOS: Physical sciences, Proportional counter, chemistry.chemical_element, Instrumentation and Detectors (physics.ins-det), Particle detector, Nuclear physics, chemistry, Observatory, Excited state, Invariant mass, Nuclear Experiment (nucl-ex), Neutrino, Nuclear Experiment, Axion
Abstract

The experimental search for solar hadronic axions is started at the Baksan Neutrino Observatory of the Institute for Nuclear Researches Russian Academy of Science. It is assumed that axions are created in the Sun during M1-transition between the first thermally excited level at 9.4 keV and the ground state in Kr-83. The experiment is based on axion detection via resonant absorption process by the same nucleus in the detector. The big copper proportional counter filled with krypton is used to detect signals from axions. The experimental setup is situated in the deep underground low background laboratory. No evidence of axion detection were found after the 26.5 days data collection. Resulting new upper limit on axion mass is m_{A} < 130 eV at 95% C.L., Talk at the International Workshop on Prospects of Particle Physics: "Neutrino Physics and Astrophysics" Jan 26 - Ferb 2, 2014, Valday, Russia, 10 pages, 5 figures

Published
2015

23. Sources of the systematic errors in measurements of 214Po decay half-life time variations at the Baksan deep underground experiments

Author

V. V. Kuzminov, S. I. Panasenko, S. S. Ratkevich, Yu. M. Gavrilyuk, A. M. Gangapshev, V. V. Kazalov, and E.N. Alexeyev

Subjects
Physics, Design modification, Systematic error, Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, Analytical chemistry, FOS: Physical sciences, Half-life, Instrumentation and Detectors (physics.ins-det), Amplitude, Annual variation, Sensitivity (control systems), Time variations, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract

The design changes of the Baksan low-background TAU-1 and TAU-2 set-ups allowed to improve a sensitivity of Po-214 half-life (\tau) measurements up to the 2.5 x 10^{-4} are described. Different possible sources of systematic errors influencing on the $\tau$-value are studed. An annual variation of Po-214 half-life time measurements with an amplitude of A=(6.9 \pm 3) x 10^{-4} and a phase of (\phi=93 \pm 10) days was found in a sequence of the week-collected \tau-values obtained from the TAU-2 data sample with total duration of 480 days. 24 hours' variation of the \tau-value measurements with an amplitude of A=(10.0 \pm 2.6) x 10^{-4} and phase of (\phi=1 \pm 0.5) hours was found in a solar day 1 hour step \tau-value sequence formed from the same data sample. It was found that the Po-214 half-life averaged at 480 days is equal to (163.45 \pm 0.04) mks., Comment: 17 pages, 6 figures, accepted for publication in Journal of Physics of Elementary Particles and Atomic Nuclei

Published
2015

24. Background free search for neutrinoless double beta decay with GERDA Phase II

Author

Agostini, M., Allardt, M., Bakalyarov, A. M., Balata, M., Barabanov, I., Baudis, L., Bauer, C., Bellotti, E., Belogurov, S., Belyaev, S. T., Benato, G., Bettini, A., Bezrukov, L., Bode, T., Borowicz, D., Brudanin, V., Brugnera, R., Caldwell, A., Cattadori, C., Chernogorov, A., D'Andrea, V., Demidova, E. V., DiMarco, N., diVacri, A., Domula, A., Doroshkevich, E., Egorov, V., Falkenstein, R., Fedorova, O., Freund, K., Frodyma, N., Gangapshev, A., Garfagnini, A., Gooch, C., Grabmayr, P., Gurentsov, V., Gusev, K., Hakenmüller, J., Hegai, A., Heisel, M., Hemmer, S., Hofmann, W., Hult, M., Inzhechik, L. V., Csáthy, J. Janicskó, Jochum, J., Junker, M., Kazalov, V., Kihm, T., Kirpichnikov, I. V., Kirsch, A., Kish, A., Klimenko, A., Kneißl, R., Knöpfle, K. T., Kochetov, O., Kornoukhov, V. N., Kuzminov, V. V., Laubenstein, M., Lazzaro, A., Lebedev, V. I., Lehnert, B., Liao, H. Y., Lindner, M., Lippi, I., Lubashevskiy, A., Lubsandorzhiev, B., Lutter, G., Macolino, C., Majorovits, B., Maneschg, W., Medinaceli, E., Miloradovic, M., Mingazheva, R., Misiaszek, M., Moseev, P., Nemchenok, I., Palioselitis, D., Panas, K., Pandola, L., Pelczar, K., Pullia, A., Riboldi, S., Rumyantseva, N., Sada, C., Salamida, F., Salathe, M., Schmitt, C., Schneider, B., Schönert, S., Schreiner, J., Schulz, O., Schütz, A. -K., Schwingenheuer, B., Selivanenko, O., Shevchik, E., Shirchenko, M., Simgen, H., Smolnikov, A., Stanco, L., Vanhoefer, L., Vasenko, A. A., Veresnikova, A., von Sturm, K., Wagner, V., Walter, M., Wegmann, A., Wester, T., Wiesinger, C., Wojcik, M., Yanovich, E., Zhitnikov, I., Zhukov, S. V., Zinatulina, D., Zuber, K., and Zuzel, G.

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

The Standard Model of particle physics cannot explain the dominance of matter over anti-matter in our Universe. In many model extensions this is a very natural consequence of neutrinos being their own anti-particles (Majorana particles) which implies that a lepton number violating radioactive decay named neutrinoless double beta ($0\nu\beta\beta$) decay should exist. The detection of this extremely rare hypothetical process requires utmost suppression of any kind of backgrounds. The GERDA collaboration searches for $0\nu\beta\beta$ decay of $^{76}$Ge ($^{76}\rm{Ge} \rightarrow\,^{76}\rm{Se} + 2e^-$) by operating bare detectors made from germanium with enriched $^{76}$Ge fraction in liquid argon. Here, we report on first data of GERDA Phase II. A background level of $\approx10^{-3}$ cts/(keV$\cdot$kg$\cdot$yr) has been achieved which is the world-best if weighted by the narrow energy-signal region of germanium detectors. Combining Phase I and II data we find no signal and deduce a new lower limit for the half-life of $5.3\cdot10^{25}$ yr at 90 % C.L. Our sensitivity of $4.0\cdot10^{25}$ yr is competitive with the one of experiments with significantly larger isotope mass. GERDA is the first $0\nu\beta\beta$ experiment that will be background-free up to its design exposure. This progress relies on a novel active veto system, the superior germanium detector energy resolution and the improved background recognition of our new detectors. The unique discovery potential of an essentially background-free search for $0\nu\beta\beta$ decay motivates a larger germanium experiment with higher sensitivity., Comment: 14 pages, 9 figures, 1 table; ; data, figures and images available at http://www.mpi-hd.mpg/gerda/public

Published
2017
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25. Limits on uranium and thorium bulk content in GERDA Phase I detectors

Author

V. N. Kornoukhov, K. Pelczar, Guillaume Lutter, A. M. Bakalyarov, K. Panas, R. Falkenstein, Jochen Schreiner, C. Schmitt, D. Palioselitis, V. G. Egorov, Allen Caldwell, K. T. Knöpfle, M. Salathe, T. Wester, O. Fedorova, V. I. Gurentsov, B. Lehnert, M. Balata, N. Frodyma, E. Medinaceli, L. Vanhoefer, K. von Sturm, T. Bode, A.A. Smolnikov, C. Cattadori, Kai Zuber, Laura Baudis, Cinzia Sada, Alessandro Bettini, O.I. Kochetov, Bayarto Lubsandorzhiev, A. Kish, R. Mingazheva, K. Freund, Marcin Wójcik, Stefano Riboldi, M. Junker, P. Grabmayr, H. Y. Liao, B. Schwingenheuer, Giovanni Benato, A.-K. Schütz, G. Zuzel, A. Hegai, S. T. Belyaev, V. D'Andrea, M. Misiaszek, C. Wiesinger, J. Jochum, A. M. Gangapshev, M. Shirchenko, V. V. Kazalov, E. V. Demidova, I. R. Barabanov, P. Moseev, Thomas Kihm, K. N. Gusev, D. R. Zinatulina, Luciano Pandola, V. I. Lebedev, A. A. Klimenko, S. V. Zhukov, M. Allardt, R. Brugnera, Stefan Schönert, L. B. Bezrukov, S. Belogurov, M. Heisel, Mikael Hult, E. Shevchik, V. V. Kuzminov, N. Rumyantseva, Matteo Agostini, Christian Bauer, A. Kirsch, A. Wegmann, Manfred Lindner, S. Hemmer, Igor Nemchenok, L. V. Inzhechik, A. Lubashevskiy, E. Doroshkevich, Bela Majorovits, W. Maneschg, A. Lazzaro, A. di Vacri, I. V. Kirpichnikov, Werner Hofmann, A. Domula, E. A. Yanovich, C. Macolino, M. Walter, B. Schneider, O. Selivanenko, R. Kneißl, Ivano Lippi, L. Stanco, V.B. Brudanin, N. Becerici-Schmidt, Hardy Simgen, E. Bellotti, D. Borowicz, M. Stepaniuk, J. Hakemüller, A. V. Veresnikova, J. Janicskó Csáthy, A. Chernogorov, I. Zhitnikov, F. Salamida, Oliver Schulz, Alberto Pullia, A. Garfagnini, Matthias Laubenstein, V. Wagner, A. A. Vasenko, Laboratoire de l'Accélérateur Linéaire (LAL), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), GERDA, and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
Physics - Instrumentation and Detectors, radiopurity, Isotopes of germanium, germanium: double-beta decay, chemistry.chemical_element, FOS: Physical sciences, double beta decay, Germanium, Radiopurity, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Uranium and thorium, germanium detectors, Nuclear physics, Double beta decay, 0103 physical sciences, thorium: admixture, germanium: detector, Nuclide, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Nuclear Experiment (nucl-ex), uranium and thorium bulk content, 010306 general physics, Nuclear Experiment, background: radioactivity, Physics, Range (particle radiation), 010308 nuclear & particles physics, uranium: admixture, Thorium, Astronomy and Astrophysics, Instrumentation and Detectors (physics.ins-det), Uranium, Germanium detectors, Uranium and thorium bulk content, chemistry, radioactivity, bulk content, DOUBLE-BETA DECAY, Decay chain, GERDA
Abstract

Internal contaminations of $^{238}$U, $^{235}$U and $^{232}$Th in the bulk of high purity germanium detectors are potential backgrounds for experiments searching for neutrinoless double beta decay of $^{76}$Ge. The data from GERDA Phase~I have been analyzed for alpha events from the decay chain of these contaminations by looking for full decay chains and for time correlations between successive decays in the same detector. No candidate events for a full chain have been found. Upper limits on the activities in the range of a few nBq/kg for $^{226}$Ra, $^{227}$Ac and $^{228}$Th, the long-lived daughter nuclides of $^{238}$U, $^{235}$U and $^{232}$Th, respectively, have been derived. With these upper limits a background index in the energy region of interest from $^{226}$Ra and $^{228}$Th contamination is estimated which satisfies the prerequisites of a future ton scale germanium double beta decay experiment., Comment: 2 figures, 7 pages

Published
2017

26. Comparative study of the double $K$-shell-vacancy production in single- and double-electron capture decay

Author

V. V. Kazalov, S. S. Ratkevich, F. F. Karpeshin, Yu. M. Gavrilyuk, M. B. Trzhaskovskaya, A. M. Gangapshev, S. I. Panasenko, S. P. Yakimenko, and V. V. Kuzminov

Subjects
Physics, 010308 nuclear & particles physics, Electron capture, Electron shell, FOS: Physical sciences, Electron, 01 natural sciences, Excited state, 0103 physical sciences, Atom, Production (computer science), Continuum (set theory), Atomic physics, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Energy (signal processing)
Abstract

We carried out the comparative study of the signal from the decay of double $K$-shell vacancy production that follows after single $K$-shell electron capture of $^{81}$Kr and double $K$-shell electron capture of $^{78}$Kr. The radiative decay of a the double $1s$ vacancy state was identified by detecting the triple coincidence of two $K$ X-rays and several Auger electrons in the $ECEC$-decay, or by detecting two $K$ X-rays and (Auger electrons + ejected $K$-shell electron) in the $EC$ decay. The number of $K$-shell vacancies per the $K$-electron capture, produced as a result of the shake-off process, has been measured for the decay of $^{81}$Kr. The probability for this decay was found to be $P_{KK}=(5.7\pm0.8)\times10^{-5}$ with a systematic error of $(\Delta P_{KK})_{syst}=\pm0.4 \times10^{-5}$. For the $^{78}{\rm{Kr}}(2\nu2K)$ decay, the comparative study of single- and double-capture decays allowed us to obtain the signal-to-background ratio to be 15/1. The half-life $T_{1/2}^{2\nu2K}(g.s. \rightarrow g.s.) = [1.9^{+1.3}_{-0.7}(stat)\pm0.3(syst)]\times 10^{22}$ y is determined from the analysis of data that have been accumulated over 782 days of live measurements in the experiment that used samples consisted of 170.6 g of $^{78}$Kr., Comment: 17 pages, 9 figures, 1 table

Published
2017
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27. The large enriched germanium experiment for neutrinoless double beta decay (LEGEND)

Author

LEGEND Collaboration, Abgrall, N., Abramov, A., Abrosimov, N., Abt, I., Agostini, M., Agartioglu, M., Ajjaq, A., Alvis, S. I., Avignone, F. T., Bai, X., Balata, M., Barabanov, I., Barabash, A. S., Barton, P. J., Baudis, L., Bezrukov, L., Bode, T., Bolozdynya, A., Borowicz, D., Boston, A., Boston, H., Boyd, S. T. P., Breier, R., Brudanin, V., Brugnera, R., Busch, M., Buuck, M., Caldwell, A., Caldwell, T. S., Camellato, T., Carpenter, M., Cattadori, C., Cederk��ll, J., Chan, Y. -D., Chen, S., Chernogorov, A., Christofferson, C. D., Chu, P. -H., Cooper, R. J., Cuesta, C., Demidova, E. V., Deng, Z., Deniz, M., Detwiler, J. A., Di Marco, N., Domula, A., Du, Q., Efremenko, Yu., Egorov, V., Elliott, S. R., Fields, D., Fischer, F., Galindo-Uribarri, A., Gangapshev, A., Garfagnini, A., Gilliss, T., Giordano, M., Giovanetti, G. K., Gold, M., Golubev, P., Gooch, C., Grabmayr, P., Green, M. P., Gruszko, J., Guinn, I. S., Guiseppe, V. E., Gurentsov, V., Gurov, Y., Gusev, K., Hakenm��eller, J., Harkness-Brennan, L., Harvey, Z. R., Haufe, C. R., Hauertmann, L., Heglund, D., Hehn, L., Heinz, A., Hiller, R., Hinton, J., Hodak, R., Hofmann, W., Howard, S., Howe, M. A., Hult, M., Inzhechik, L. V., Cs��thy, J. Janicsk��, Janssens, R., Je��kovsk��, M., Jochum, J., Johansson, H. T., Judson, D., Junker, M., Kaizer, J., Kang, K., Kazalov, V., Kerma��dic, Y., Kiessling, F., Kirsch, A., Kish, A., Klimenko, A., Kn��pfle, K. T. K. T., Kochetov, O., Konovalov, S. I., Kontul, I., Kornoukhov, V. N., Kraetzschmar, T., Kr��ninger, K., Kumar, A., Kuzminov, V. V., Lang, K., Laubenstein, M., Lazzaro, A., Li, Y. L., Li, Y. -Y., Li, H. B., Lin, S. T., Lindner, M., Lippi, I., Liu, S. K., Liu, X., Liu, J., Loomba, D., Lubashevskiy, A., Lubsandorzhiev, B., Lutter, G., Ma, H., Majorovits, B., Mamedov, F., Martin, R. D., Massarczyk, R., Matthews, J. A. J., McFadden, N., Mei, D. -M., Mei, H., Meijer, S. J., Mengoni, D., Mertens, S., Miller, W., Miloradovic, M., Mingazheva, R., Misiaszek, M., Moseev, P., Myslik, J., Nemchenok, I., Nilsson, T., Nolan, P., O'Shaughnessy, C., Othman, G., Panas, K., Pandola, L., Papp, L., Pelczar, K., Peterson, D., Pettus, W., Poon, A. W. P., Povinec, P. P., Pullia, A., Quintana, X. C., Radford, D. C., Rager, J., Ransom, C., Recchia, F., Reine, A. L., Riboldi, S., Rielage, K., Rozov, S., Rouf, N. W., Rukhadze, E., Rumyantseva, N., Saakyan, R., Sala, E., Salamida, F., Sandukovsky, V., Savard, G., Sch��nert, S., Sch��tz, A. -K., Schulz, O., Schuster, M., Schwingenheuer, B., Selivanenko, O., Sevda, B., Shanks, B., Shevchik, E., Shirchenko, M., Simkovic, F., Singh, L., Singh, V., Skorokhvatov, M., Smolek, K., Smolnikov, A., Sonay, A., Spavorova, M., Stekl, I., Stukov, D., Tedeschi, D., Thompson, J., Van Wechel, T., Varner, R. L., Vasenko, A. A., Vasilyev, S., Veresnikova, A., Vetter, K., von Sturm, K., Vorren, K., Wagner, M., Wang, G. -J., Waters, D., Wei, W. -Z., Wester, T., White, B. R., Wiesinger, C., Wilkerson, J. F., Willers, M., Wiseman, C., Wojcik, M., Wong, H. T., Wyenberg, J., Xu, W., Yakushev, E., Yang, G., Yu, C. -H., Yue, Q., Yumatov, V., Zeman, J., Zeng, Z., Zhitnikov, I., Zhu, B., Zinatulina, D., Zschocke, A., Zsigmond, A. J., Zuber, K., and Zuzel, G.

Subjects
Particle physics, Physics - Instrumentation and Detectors, Physics::Instrumentation and Detectors, chemistry.chemical_element, FOS: Physical sciences, Germanium, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Physics and Astronomy (all), Double beta decay, Nuclear Matrix, Beta (velocity), Nuclear Experiment (nucl-ex), Nuclear Experiment, Physics, High Energy Physics::Phenomenology, Instrumentation and Detectors (physics.ins-det), Beta Decay, Bolometers, Lepton number, Beta Decay, Bolometers, Nuclear Matrix, MAJORANA, chemistry, High Energy Physics::Experiment, Neutrino, Order of magnitude, Energy (signal processing)
Abstract

The observation of neutrinoless double-beta decay (0${\nu}{\beta}{\beta}$) would show that lepton number is violated, reveal that neutrinos are Majorana particles, and provide information on neutrino mass. A discovery-capable experiment covering the inverted ordering region, with effective Majorana neutrino masses of 15 - 50 meV, will require a tonne-scale experiment with excellent energy resolution and extremely low backgrounds, at the level of $\sim$0.1 count /(FWHM$\cdot$t$\cdot$yr) in the region of the signal. The current generation $^{76}$Ge experiments GERDA and the MAJORANA DEMONSTRATOR utilizing high purity Germanium detectors with an intrinsic energy resolution of 0.12%, have achieved the lowest backgrounds by over an order of magnitude in the 0${\nu}{\beta}{\beta}$ signal region of all 0${\nu}{\beta}{\beta}$ experiments. Building on this success, the LEGEND collaboration has been formed to pursue a tonne-scale $^{76}$Ge experiment. The collaboration aims to develop a phased 0${\nu}{\beta}{\beta}$ experimental program with discovery potential at a half-life approaching or at $10^{28}$ years, using existing resources as appropriate to expedite physics results., Comment: Proceedings of the MEDEX'17 meeting (Prague, May 29 - June 2, 2017)

Published
2017

28. Limit on the radiative neutrinoless double electron capture of$^{36}$ Ar from GERDA Phase I

Author

Agostini , M., Allardt , M., Bakalyarov , A.M., Balata , M., Barabanov , I., Barros , N., Baudis , L., Bauer , C., Bellotti , E., Belogurov , S., Belyaev , S.T., Benato , G., Bettini , A., Bezrukov , L., Bode , T., Borowicz , D., Brudanin , V., Brugnera , R., Caldwell , A., Cattadori , C., Chernogorov , A., D'Andrea , V., Demidova , E.V., Di Vacri , A., Domula , A., Doroshkevich , E., Egorov , V., Falkenstein , R., Fedorova , O., Freund , K., Frodyma , N., Gangapshev , A., Garfagnini , A., Gooch , C., Grabmayr , P., Gurentsov , V., Gusev , K., Hakenmüller , J., Hegai , A., Heisel , M., Hemmer , S., Heusser , G., Hofmann , W., Hult , M., Inzhechik , L.V., Csathy , J.Janicsko, Jochum , J., Junker , M., Kazalov , V., Kihm , T., Kirpichnikov , I.V., Kirsch , A., Kish , A., Klimenko , A., Kneißl , R., Knöpfle , K.T., Kochetov , O., Kornoukhov , V.N., Kuzminov , V.V., Laubenstein , M., Lazzaro , A., Lebedev , V.I., Lehnert , B., Liao , H.Y., Lindner , M., Lippi , I., Lubashevskiy , A., Lubsandorzhiev , B., Lutter , G., Macolino , C., Majorovits , B., Maneschg , W., Medinaceli , E., Miloradovic , M., Mingazheva , R., Misiaszek , M., Moseev , P., Nemchenok , I., Palioselitis , D., Panas , K., Pandola , L., Pelczar , K., Pullia , A., Riboldi , S., Rumyantseva , N., Sada , C., Salamida , F., Salathe , M., Schmitt , C., Schneider , B., Schönert , S., Schreiner , J., Schütz , A.K., Schulz , O., Schwingenheuer , B., Selivanenko , O., Shirchenko , M., Simgen , H., Smolnikov , A., Stanco , L., Stepaniuk , M., Vanhoefer , L., Vasenko , A.A., Veresnikova , A., von Sturm , K., Wagner , V., Walter , M., Wegmann , A., Wester , T., Wiesinger , C., Wilsenach , H., Wojcik , M., Yanovich , E., Zhitnikov , I., Zhukov , S.V., Zinatulina , D., Zuber , K., Zuzel , G., Laboratoire de l'Accélérateur Linéaire (LAL), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), GERDA, Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Laboratoire de l'Accélérateur Linéaire ( LAL ), and Université Paris-Sud - Paris 11 ( UP11 ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS )

Subjects
energy spectrum, FOS: Physical sciences, resolution, electron: capture, radiative capture, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], High Energy Physics - Experiment, Gran Sasso, energy dependence, Auger, liquid argon, High Energy Physics - Experiment (hep-ex), (0neutrino), [ PHYS.HEXP ] Physics [physics]/High Energy Physics - Experiment [hep-ex], statistics, efficiency, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], germanium: detector, [ PHYS.NEXP ] Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment (nucl-ex), Nuclear Experiment, Monte Carlo, lepton number: violation, Majorana, GERDA
Abstract

Neutrinoless double electron capture is a process that, if detected, would give evidence of lepton number violation and the Majorana nature of neutrinos. A search for neutrinoless double electron capture of $^{36}$Ar has been performed with germanium detectors installed in liquid argon using data from Phase I of the GERmanium Detector Array (GERDA) experiment at the Gran Sasso Laboratory of INFN, Italy. No signal was observed and an experimental lower limit on the half-life of the radiative neutrinoless double electron capture of $^{36}$Ar was established: $T_{1/2} > $ 3.6 $\times$ 10$^{21}$ yr at 90 % C.I., 7 pages, 3 figures

Published
2016

29. Pulse shape discrimination for GERDA Phase I data

Author

S. Hemmer, V. Wagner, A. A. Vasenko, N. Becerici-Schmidt, J. Schreiner, V. I. Lebedev, Thomas Kihm, H. Strecker, Manfred Lindner, L. V. Inzhechik, T. Wester, A.A. Smolnikov, Alessandro Bettini, M. Barnabe Heider, C. Cattadori, Kai Zuber, Allen Caldwell, V. I. Gurentsov, A. Kirsch, M. Heisel, A. A. Machado, D. Budjáš, E. Bellotti, V. Brudanin, Stefan Schönert, K. K. Guthikonda, Xianpeng Liu, Oliver Schulz, K. von Sturm, A. Domula, L. B. Bezrukov, H. Simgen, E. Shevchik, Alberto Pullia, Bayarto Lubsandorzhiev, Christian Bauer, I. R. Barabanov, K. Freund, A. Garfagnini, M. Junker, L. Ioannucci, Marcin Wójcik, S. V. Zhukov, G. Pessina, P. Grabmayr, V. Egorov, M. Allardt, R. Brugnera, A. Lubashevskiy, Luca Stanco, D. R. Zinatulina, Marc Walter, N. Frodyma, V. V. Kuzminov, J. Janicskó Csáthy, Matteo Agostini, Werner Hofmann, Cinzia Sada, Giovanni Benato, Claudio Gotti, M. Balata, C. Macolino, Mikael Hult, T. Bode, A. D. Ferella, B. Schwingenheuer, I. Zhitnikov, G. Heusser, K. T. Knöpfle, A. Hegai, G. Zuzel, O.I. Kochetov, W. Hampel, S. T. Belyaev, A. M. Gangapshev, E. V. Demidova, S. Belogurov, A. Wegmann, Igor Nemchenok, Bela Majorovits, M. Salathe, S. Nisi, Luciano Pandola, I. V. Kirpichnikov, A. A. Klimenko, N. Rumyantseva, B. Lehnert, O. Volynets, Ivano Lippi, K. N. Gusev, W. Maneschg, E. A. Yanovich, Stefano Riboldi, V. N. Kornoukhov, K. Pelczar, E. Andreotti, M. Misiaszek, M. Shirchenko, Laura Baudis, C. A. Ur, N. Barros, H. Y. Liao, Guillaume Lutter, A. Chernogorov, A. M. Bakalyarov, J. Jochum, F. Cossavella, M. Tarka, R. Falkenstein, C. Schmitt, C.M. O'Shaughnessy, A. Lazzaro, Matthias Laubenstein, P. Zavarise, Agostini, M, Allardt, M, Andreotti, E, Bakalyarov, A, Balata, M, Barabanov, I, Barnabé Heider, M, Barros, N, Baudis, L, Bauer, C, Becerici Schmidt, N, Bellotti, E, Belogurov, S, Belyaev, S, Benato, G, Bettini, A, Bezrukov, L, Bode, T, Brudanin, V, Brugnera, R, Budjáš, D, Caldwell, A, Cattadori, C, Chernogorov, A, Cossavella, F, Demidova, E, Domula, A, Egorov, V, Falkenstein, R, Ferella, A, Freund, K, Frodyma, N, Gangapshev, A, Garfagnini, A, Gotti, C, Grabmayr, P, Gurentsov, V, Gusev, K, Guthikonda, K, Hampel, W, Hegai, A, Heisel, M, Hemmer, S, Heusser, G, Hofmann, W, Hult, M, Inzhechik, L, Ioannucci, L, Janicskó Csáthy, J, Jochum, J, Junker, M, Kihm, T, Kirpichnikov, I, Kirsch, A, Klimenko, A, Knöpfle, K, Kochetov, O, Kornoukhov, V, Kuzminov, V, Laubenstein, M, Lazzaro, A, Lebedev, V, Lehnert, B, Liao, H, Lindner, M, Lippi, I, Liu, X, Lubashevskiy, A, Lubsandorzhiev, B, Lutter, G, Macolino, C, Machado, A, Majorovits, B, Maneschg, W, Misiaszek, M, Nemchenok, I, Nisi, S, O'Shaughnessy, C, Pandola, L, Pelczar, K, Pessina, G, Pullia, A, Riboldi, S, Rumyantseva, N, Sada, C, Salathe, M, Schmitt, C, Schreiner, J, Schulz, O, Schwingenheuer, B, Schönert, S, Shevchik, E, Shirchenko, M, Simgen, H, Smolnikov, A, Stanco, L, Strecker, H, Tarka, M, Ur, C, Vasenko, A, Volynets, O, von Sturm, K, Wagner, V, Walter, M, Wegmann, A, Wester, T, Wojcik, M, Yanovich, E, Zavarise, P, Zhitnikov, I, Zhukov, S, Zinatulina, D, Zuber, K, and Zuzel, G

Subjects
Physics, Particle physics, Physics - Instrumentation and Detectors, Physics and Astronomy (miscellaneous), Detector, Phase (waves), chemistry.chemical_element, FOS: Physical sciences, Germanium, Compton edge, Instrumentation and Detectors (physics.ins-det), Type (model theory), Shape parameter, chemistry, Beta (velocity), Sensitivity (control systems), Nuclear Experiment (nucl-ex), Engineering (miscellaneous), Nuclear Experiment
Abstract

The GERDA experiment located at the LNGS searches for neutrinoless double beta (0\nu\beta\beta) decay of ^{76}Ge using germanium diodes as source and detector. In Phase I of the experiment eight semi-coaxial and five BEGe type detectors have been deployed. The latter type is used in this field of research for the first time. All detectors are made from material with enriched ^{76}Ge fraction. The experimental sensitivity can be improved by analyzing the pulse shape of the detector signals with the aim to reject background events. This paper documents the algorithms developed before the data of Phase I were unblinded. The double escape peak (DEP) and Compton edge events of 2.615 MeV \gamma\ rays from ^{208}Tl decays as well as 2\nu\beta\beta\ decays of ^{76}Ge are used as proxies for 0\nu\beta\beta\ decay. For BEGe detectors the chosen selection is based on a single pulse shape parameter. It accepts 0.92$\pm$0.02 of signal-like events while about 80% of the background events at Q_{\beta\beta}=2039 keV are rejected. For semi-coaxial detectors three analyses are developed. The one based on an artificial neural network is used for the search of 0\nu\beta\beta\ decay. It retains 90% of DEP events and rejects about half of the events around Q_{\beta\beta}. The 2\nu\beta\beta\ events have an efficiency of 0.85\pm0.02 and the one for 0\nu\beta\beta\ decays is estimated to be 0.90^{+0.05}_{-0.09}. A second analysis uses a likelihood approach trained on Compton edge events. The third approach uses two pulse shape parameters. The latter two methods confirm the classification of the neural network since about 90% of the data events rejected by the neural network are also removed by both of them. In general, the selection efficiency extracted from DEP events agrees well with those determined from Compton edge events or from 2\nu\beta\beta\ decays., Comment: 18 pages, 27 figures

Published
2013

30. Results of measurements of an environment neutron background at BNO INR RAS objects with the helium proportional counter

Author

Alekseenko, V. V., Barabanov, I. R., Etezov, R. A., Gavrilyuk, Yu. M., Gangapshev, A. M., Gezhaev, A. M., Kazalov, V. V., Khokonov, A. Kh., Kuzminov, V. V., Panasenko, S. I., and Ratkevich, S. S.

Subjects
Physics - Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, High Energy Physics::Experiment, Instrumentation and Detectors (physics.ins-det), Nuclear Experiment (nucl-ex), Nuclear Experiment, Physics::Geophysics
Abstract

A method of measurements of the environmental neutron background at the Baksan Neutrino Observatory of the INR RAS are described. Measurements were done by using of a proportional counter filled with mixture of Ar(2 at)+$^3$He(4 at). The results obtained at the surface and the underground laboratory of the BNO INR RAS are presented. It is shown that a neutron background in the underground laboratory at the 4900 m w.e. depth is decreased by $\sim 260$ times without any special shield in a comparison with the Earth surface. A neutron flux density in the 5-1323.5~cm air height region is constant within the determination error and equal to $(7.1\pm0.1_{\rm{stat}}\pm0.3_{\rm{syst}})\times10^{-3}$ s$^{-1}\cdot$cm$^{-2}$., 5 pages, 4 figures, 2 tables

Published
2015

31. The origin of the background radioactive isotope Xe-127 in the sample of Xe enriched in Xe-124

Author

Gavrilyuk, Yu. M., Gangapshev, A. M., Kazalov, V. V., Kuzminov, V. V., Panasenko, S. I., Ratkevich, S. S., Tekueva, D. A., and Yakimenko, S. P.

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

The results of investigation of Xe-127 radioactive isotope production in the xenon sample enriched in Xe-124, Xe-126, Xe-128 are presented. The isotope is supposed to be the source of the background events in the low-background experiment on search for 2K-capture of Xe-124. In this work we consider two channels of Xe-127 production: the neutron knock-out from Xe-128 nucleus by cosmogenic muons and the neutron capture by Xe-126 nucleus. For the first channel the upper limit of the cross section of Xe-127 production was found to be sigma >= 0.007 barn at 95\% C.L. For the second channel the value obtained for the cross section was found to be equal to sigma =(2.74+-0.4) barn, which coincides well, within the statistical error, with reference value., Talk at The International Workshop on Prospects of Particle Physics: "Neutrino Physics and Astrophysics" Ferbuary 1 - 8, 2015, Valday,Russia, 4 pages, 5 figures, 1 tabel (to be published in PEPAN)

Published
2015

32. $2������$ decay of $^{76}$Ge into excited states with GERDA Phase I

Author

Agostini, M., Allardt, M., Bakalyarov, A. M., Balata, M., Barabanov, I., Barros, N., Baudis, L., Bauer, C., Becerici-Schmidt, N., Bellotti, E., Belogurov, S., Belyaev, S. T., Benato, G., Bettini, A., Bezrukov, L., Bode, T., Borowicz, D., Brudanin, V., Brugnera, R., Budj����, D., Caldwell, A., Cattadori, C., Chernogorov, A., D'Andrea, V., Demidova, E. V., di Vacri, A., Domula, A., Doroshkevich, E., Egorov, V., Falkenstein, R., Fedorova, O., Freund, K., Frodyma, N., Gangapshev, A., Garfagnini, A., Gooch, C., Grabmayr, P., Gurentsov, V., Gusev, K., Hegai, A., Heisel, M., Hemmer, S., Heusser, G., Hofmann, W., Hult, M., Inzhechik, L. V., Cs��thy, J. Janicsk��, Jochum, J., Junker, M., Kazalov, V., Kihm, T., Kirpichnikov, I. V., Kirsch, A., Klimenko, A., Kn��pfle, K. T., Kochetov, O., Kornoukhov, V. N., Kuzminov, V. V., Laubenstein, M., Lazzaro, A., Lebedev, V. I., Lehnert, B., Liao, H. Y., Lindner, M., Lippi, I., Lubashevskiy, A., Lubsandorzhiev, B., Lutter, G., Macolino, C., Majorovits, B., Maneschg, W., Medinaceli, E., Mi, Y., Misiaszek, M., Moseev, P., Nemchenok, I., Palioselitis, D., Panas, K., Pandola, L., Pelczar, K., Pullia, A., Riboldi, S., Rumyantseva, N., Sada, C., Salathe, M., Schmitt, C., Schneider, B., Schreiner, J., Schulz, O., Schwingenheuer, B., Sch��nert, S., Sch��tz, A-K., Selivanenko, O., Shirchenko, M., Simgen, H., Smolnikov, A., Stanco, L., Stepaniuk, M., Ur, C. A., Vanhoefer, L., Vasenko, A. A., Veresnikova, A., von Sturm, K., Wagner, V., Walter, M., Wegmann, A., Wester, T., Wilsenach, H., Wojcik, M., Yanovich, E., Zavarise, P., Zhitnikov, I., Zhukov, S. V., Zinatulina, D., Zuber, K., and Zuzel, G.

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

Two neutrino double beta decay of $^{76}$Ge to excited states of $^{76}$Se has been studied using data from Phase I of the GERDA experiment. An array composed of up to 14 germanium detectors including detectors that have been isotopically enriched in $^{76}$Ge was deployed in liquid argon. The analysis of various possible transitions to excited final states is based on coincidence events between pairs of detectors where a de-excitation $��$ ray is detected in one detector and the two electrons in the other. No signal has been observed and an event counting profile likelihood analysis has been used to determine Frequentist 90\,\% C.L. bounds for three transitions: ${0^+_{\rm g.s.}-2^+_1}$: $T^{2��}_{1/2}>$1.6$\cdot10^{23}$ yr, ${0^+_{\rm g.s.}-0^+_1}$: $T^{2��}_{1/2}>$3.7$\cdot10^{23}$ yr and ${0^+_{\rm g.s.}-2^+_2}$: $T^{2��}_{1/2}>$2.3$\cdot10^{23}$ yr. These bounds are more than two orders of magnitude larger than those reported previously. Bayesian 90\,\% credibility bounds were extracted and used to exclude several models for the ${0^+_{\rm g.s.}-0^+_1}$ transition.

Published
2015
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33. Production, characterization and operation of ^{76}Ge enriched BEGe detectors in GERDA

Author

Agostini, M., Allardt, M., Andreotti, E., Bakalyarov, A. M., Balata, M., Barabanov, I., Barros, N., Baudis, L., Bauer, C., Becerici-Schmidt, N., Bellotti, E., Belogurov, S., Belyaev, S. T., Benato, G., Bettini, A., Bezrukov, L., Bode, T., Borowicz, D., Brudanin, V., Brugnera, R., Budjas, D., Caldwel, A., Cattadori, C., Chernogorov, A., D'Andrea, V., Demidova, E. V., Domula, A., Egorov, V., Falkenstein, R., Freund, K., Frodyma, N., Gangapshev, A., Garfagnini, A., Gotti, C., Grabmayr, P., Gurentsov, V., Gusev, K., Hampel, W., Hegai, A., Heisel, M., Hemmer, S., Heusser, G., Hofmann, W., Hult, M., Inzhechik, L. V., Ioannucci, L., Csathy, J. Janicsko, Jochum, J., Junker, M., Kazalov, V., Kihm, T., Kirpichnikov, I. V., Kirsch, A., Klimenko, A., Knöpfle, K. T., Kochetov, O., Kornoukhov, V. N., Kuzminov, V. V., Laubenstein, M., Lazzaro, A., Lebedev, V. I., Lehnert, B., Liao, H. Y., Lindner, M., Lippi, I., Lubashevskiy, A., Lubsandorzhiev, B., Lutter, G., Macolino, C., Majorovits, B., Maneschg, W., Misiaszek, M., Nemchenok, I., Nisi, S., O'Shaughnessy, C., Palioselitis, D., Pandola, L., Pelczar, K., Pessina, G., Pullia, A., Riboldi, S., Rumyantseva, N., Sada, C., Salathe, M., Schmitt, C., Schreiner, J., Schulz, O., Schwingenheuer, B., Schönert, S., Shevchik, E., Shirchenko, M., Simgen, H., Smolnikov, A., Stanco, L., Strecker, H., Ur, C. A., Vanhoefer, L., Vasenko, A. A., von Sturm, K., Wagner, V., Walter, M., Wegmann, A., Wester, T., Wilsenach, H., Wojcik, M., Yanovich, E., Zavarise, P., Zhitnikov, I., Zhukov, S. V., Zinatulina, D., Zuber, K., Zuzel, G., and GERDA Collaboration

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

The GERmanium Detector Array (GERDA) at the Gran Sasso Underground Laboratory (LNGS) searches for the neutrinoless double beta decay (0{\nu}{\beta}{\beta}) of $^{76}$Ge. Germanium detectors made of material with an enriched $^{76}$Ge fraction act simultaneously as sources and detectors for this decay. During Phase I of the experiment mainly refurbished semi-coaxial Ge detectors from former experiments were used. For the upcoming Phase II, 30 new $^{76}$Ge enriched detectors of broad energy germanium (BEGe)-type were produced. A subgroup of these detectors has already been deployed in GERDA during Phase I. The present paper reviews the complete production chain of these BEGe detectors including isotopic enrichment, purification, crystal growth and diode production. The efforts in optimizing the mass yield and in minimizing the exposure of the $^{76}$Ge enriched germanium to cosmic radiation during processing are described. Furthermore, characterization measurements in vacuum cryostats of the first subgroup of seven BEGe detectors and their long-term behavior in liquid argon are discussed. The detector performance fulfills the requirements needed for the physics goals of GERDA Phase~II., Comment: 23 pages, 21 figures

Published
2015

34. LArGe - Active background suppression using argon scintillation for the GERDA $0������$-experiment

Author

Agostini, M., Barnab��-Heider, M., Budj����, D., Cattadori, C., Gangapshev, A., Gusev, K., Heisel, M., Junker, M., Klimenko, A., Lubashevskiy, A., Pelczar, K., Sch��nert, S., Smolnikov, A., and Zuzel, G.

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

LArGe is a GERDA low-background test facility to study novel background suppression methods in a low-background environment, for future application in the GERDA experiment. Similar to GERDA, LArGe operates bare germanium detectors submersed into liquid argon (1 m$^3$, 1.4 tons), which in addition is instrumented with photomultipliers to detect argon scintillation light. The scintillation signals are used in anti-coincidence with the germanium detectors to effectively suppress background events that deposit energy in the liquid argon. The background suppression efficiency was studied in combination with a pulse shape discrimination (PSD) technique using a BEGe detector for various sources, which represent characteristic backgrounds to GERDA. Suppression factors of a few times $10^3$ have been achieved. First background data of LArGe with a coaxial HPGe detector (without PSD) yield a background index of (0.12$-$4.6)$\cdot 10^{-2}$ cts/(keV$\cdot$kg$\cdot$y) (90% C.L.), which is at the level of GERDA Phase I. Furthermore, for the first time we monitor the natural $^{42}$Ar abundance (parallel to GERDA), and have indication for the $2������$-decay in natural germanium. These results show the effectivity of an active liquid argon veto in an ultra-low background environment. As a consequence, the implementation of a liquid argon veto in GERDA Phase II is pursued.

Published
2015
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35. Improvement of the energy resolution via an optimized digital signal processing in GERDA Phase I

Author

M. Shirchenko, D. Palioselitis, Laura Baudis, I. V. Kirpichnikov, J. Janicskó Csáthy, I. Zhitnikov, Oliver Schulz, H. Y. Liao, W. Maneschg, E. A. Yanovich, N. Barros, Alberto Pullia, J. Jochum, V. N. Kornoukhov, K. Pelczar, A. Garfagnini, L. V. Inzhechik, A.-K. Schütz, A. Hegai, C. Macolino, V. I. Gurentsov, Manfred Lindner, V. V. Kazalov, Allen Caldwell, A. V. Veresnikova, A. Wegmann, Igor Nemchenok, Marc Walter, Guillaume Lutter, A. M. Bakalyarov, V. I. Lebedev, M. Heisel, Bayarto Lubsandorzhiev, A. Chernogorov, T. Wester, B. Lehnert, O. Fedorova, A.A. Smolnikov, Bela Majorovits, K. von Sturm, C. Cattadori, Matthias Laubenstein, P. Zavarise, Kai Zuber, M. Balata, N. Frodyma, R. Brugnera, O. Selivanenko, D. Budjáš, V. Egorov, V. Wagner, K. N. Gusev, E. V. Demidova, L. Vanhoefer, V. V. Kuzminov, Matteo Agostini, T. Bode, Ivano Lippi, A. di Vacri, O.I. Kochetov, Werner Hofmann, E. Bellotti, M. Allardt, A. A. Vasenko, E. Doroshkevich, L. B. Bezrukov, E. Medinaceli, Stefan Schönert, Christian Bauer, S. T. Belyaev, K. Freund, A. Lubashevskiy, A. M. Gangapshev, S. Belogurov, M. Salathe, B. Schwingenheuer, R. Falkenstein, Cinzia Sada, C. Schmitt, Giovanni Benato, Stefano Riboldi, Thomas Kihm, D. R. Zinatulina, C. A. Ur, A. Domula, P. Moseev, G. Heusser, Luciano Pandola, M. Misiaszek, A. A. Klimenko, Marcin Wójcik, P. Grabmayr, N. Rumyantseva, Alessandro Bettini, V.B. Brudanin, A. Kirsch, Hardy Simgen, Mikael Hult, S. Hemmer, J. Schreiner, B. Schneider, I. R. Barabanov, S. V. Zhukov, N. Becerici-Schmidt, H. Wilsenach, M. Stepaniuk, K. Panas, D. Borowicz, Luca Stanco, K. T. Knöpfle, G. Zuzel, V. D'Andrea, A. Lazzaro, and M. Junker

Subjects
Physics - Instrumentation and Detectors, Physics and Astronomy (miscellaneous), Isotopes of germanium, Q value, Physics::Instrumentation and Detectors, Phase (waves), FOS: Physical sciences, GERMANIUM DETECTORS, 01 natural sciences, Noise (electronics), Particle detector, GERDA - Abteilung Hofmann, Nuclear physics, Nuclear magnetic resonance, Double beta decay, 0103 physical sciences, CHARGE MEASUREMENTS, Nuclear Experiment (nucl-ex), 010306 general physics, SILICON, Engineering (miscellaneous), Nuclear Experiment, Physics, 010308 nuclear & particles physics, Instrumentation and Detectors (physics.ins-det), MINIMUM-NOISE, GENIUS, GE-76, DECAY, PROJECT, Radioactive decay, Energy (signal processing), OPTIMUM FILTERS
Abstract

An optimized digital shaping filter has been developed for the GERDA experiment which searches for neutrinoless double beta decay in 76Ge. The GERDA Phase I energy calibration data have been reprocessed and an average improvement of 0.3 keV in energy resolution (FWHM) at the 76Ge Q value for 0\nu\beta\beta decay is obtained. This is possible thanks to the enhanced low-frequency noise rejection of this Zero Area Cusp (ZAC) signal shaping fillter., Comment: 12 pages, 16 figures

Published
2015

36. The study of the thermal neutron flux in the deep underground laboratory DULB-4900

Author

Alekseenko, V. V., Gavrilyuk, Yu. M., Gangapshev, A. M., Gezhaev, A. M., Dzhappuev, D. D., Kazalov, V. V., Kudzhaev, A. U., Kuzminov, V. V., Panasenko, S. I., Ratkevich, S. S., Tekueva, D. A., Yakimenko, S. P., and Sten'kin, Yu. V.

Subjects
Physics - Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract

We report on the study of thermal neutron flux using monitors based on mixture of ZnS(Ag) and LiF enriched with a lithium-6 isotope at the deep underground laboratory DULB-4900 at the Baksan Neutrino Observatory. An annual modulation of thermal neutron flux in DULB-4900 is observed. Experimental evidences were obtained of correlation between the long-term thermal neutron flux variations and the absolute humidity of the air in laboratory. The amplitude of the modulation exceed 5\% of total neutron flux., Comment: 9 pages, 9 figures, Talk at The International Workshop on Prospects of Particle Physics: "Neutrino Physics and Astrophysics" February 01 - Ferbuary 08, 2015, Valday, Russia

Published
2015
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37. Search for 2K(2��)-capture of Xe-124

Author

Gavrilyuk, Yu. M., Gangapshev, A. M., Kazalov, V. V., Kuzminov, V. V., Panasenko, S. I., Ratkevich, S. S., Tekueva, D. A., and Yakimenko, S. P.

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

The results of a search for two neutrino mode of double K-capture of Xe-124 using a large copper low-background proportional counter are presented. Data collected during 3220 hours of measurements with 58.6 g of $^{124}$Xe provides us to a new limit on the half-life of Xe-124 regarding 2K-capture at the level: T_{1/2} >= 2.0*10^{21} years at a 90\% confidence level., 9 pages, 4 figures, Talk at The International Workshop on Prospects of Particle Physics: "Neutrino Physics and Astrophysics" February 01 - Ferbuary 08, 2015, Valday, Russia

Published
2015
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38. First result of the experimental search for the 2K-capture of Xe-124 with the copper proportional counter

Author

V. V. Kazalov, V. V. Kuzminov, D. A. Tekueva, A. M. Gangapshev, S. S. Ratkevich, S. P. Yakimenko, Yu. M. Gavrilyuk, and S. I. Panasenko

Subjects
Physics, Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, Analytical chemistry, Proportional counter, chemistry.chemical_element, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), Copper, Volume (thermodynamics), chemistry, Nuclear Experiment (nucl-ex), Ground state, Nuclear Experiment
Abstract

First result of experiment for searching of 2K-capture of Xe-124 with the large-volume copper proportional counter is given. The 12 litre sample with 63.3% (44 g) of Xe-124 was used in measurements. The limit on the half-life of Xe-124 with regard to 2K(2��)-capture for the ground state of Te-124 has been found: T_{1/2} > 4.67x10^{20} y (90% C.L.). A sample with volume 52 L comprising of Xe-124 (10.6 L - 58.6 g) and Xe-126 (14.1 L - 79.3 g) will used at the next step of the experiment to increase a sensitivity of 2K-caption of Xe-124 registration. In this case sensitivity to the investigated process will be at the level of S=1.46 x 10^{21} y (90% C.L.) for 1 year measurement., Talk at the International Workshop on Prospects of Particle Physics: "Neutrino Physics and Astrophysics" Jan 26 - Ferb 2, 2014, Valday, Russia, 9 pages, 4 figure and 2 tables

Published
2014

39. Results on neutrinoless double beta decay of 76Ge from GERDA Phase I

Author

Agostini, M., Allardt, M., Andreotti, E., Bakalyarov, A. M., Balata, M., Barabanov, I., Heider, M. Barnab��, Barros, N., Baudis, L., Bauer, C., Becerici-Schmidt, N., Bellotti, E., Belogurov, S., Belyaev, S. T., Benato, G., Bettini, A., Bezrukov, L., Bode, T., Brudanin, V., Brugnera, R., Budj����, D., Caldwell, A., Cattadori, C., Chernogorov, A., Cossavella, F., Demidova, E. V., Domula, A., Egorov, V., Falkenstein, R., Ferella, A., Freund, K., Frodyma, N., Gangapshev, A., Garfagnini, A., Gotti, C., Grabmayr, P., Gurentsov, V., Gusev, K., Guthikonda, K. K., Hampel, W., Hegai, A., Heisel, M., Hemmer, S., Heusser, G., Hofmann, W., Hult, M., Inzhechik, L. V., Ioannucci, L., Cs��thy, J. Janicsk��, Jochum, J., Junker, M., Kihm, T., Kirpichnikov, I. V., Kirsch, A., Klimenko, A., Kn��pfle, K. T., Kochetov, O., Kornoukhov, V. N., Kuzminov, V. V., Laubenstein, M., Lazzaro, A., Lebedev, V. I., Lehnert, B., Liao, H. Y., Lindner, M., Lippi, I., Liu, X., Lubashevskiy, A., Lubsandorzhiev, B., Lutter, G., Macolino, C., Machado, A. A., Majorovits, B., Maneschg, W., Misiaszek, M., Nemchenok, I., Nisi, S., O'Shaughnessy, C., Pandola, L., Pelczar, K., Pessina, G., Potenza, %F., Pullia, A., Riboldi, S., Rumyantseva, N., Sada, C., Salathe, M., Schmitt, C., Schreiner, J., Schulz, O., Schwingenheuer, B., Sch��nert, S., Shevchik, E., Shirchenko, M., Simgen, H., Smolnikov, A., Stanco, L., Strecker, H., Tarka, M., Ur, C. A., Vasenko, A. A., Volynets, O., von Sturm, K., Wagner, V., Walter, M., Wegmann, A., Wester, T., Wojcik, M., Yanovich, E., Zavarise, P., Zhitnikov, I., Zhukov, S. V., Zinatulina, D., Zuber, K., and Zuzel, G.

Subjects
High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), FOS: Physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment, High Energy Physics - Experiment
Abstract

Neutrinoless double beta decay is a process that violates lepton number conservation. It is predicted to occur in extensions of the Standard Model of particle physics. This Letter reports the results from Phase I of the GERmanium Detector Array (GERDA) experiment at the Gran Sasso Laboratory (Italy) searching for neutrinoless double beta decay of the isotope 76Ge. Data considered in the present analysis have been collected between November 2011 and May 2013 with a total exposure of 21.6 kgyr. A blind analysis is performed. The background index is about 1.10^{-2} cts/(keV kg yr) after pulse shape discrimination. No signal is observed and a lower limit is derived for the half-life of neutrinoless double beta decay of 76Ge, T_1/2 > 2.1 10^{25} yr (90% C.L.). The combination with the results from the previous experiments with 76Ge yields T_1/2 > 3.0 10^{25} yr (90% C.L.)., 6 pages, 2 figures

Published
2013

40. Measurement of the half-life of the two-neutrino double beta decay of Ge-76 with the Gerda experiment

Author

GERDA Collaboration, Agostini, M., Allardt, M., Andreotti, E., Bakalyarov, A. M., Balata, M., Barabanov, I., Heider, M. Barnabe, Barros, N., Baudis, L., Bauer, C., Becerici-Schmidt, N., Bellotti, E., Belogurov, S., Belyaev, S. T., Benato, G., Bettini, A., Bezrukov, L., Bode, T., Brudanin, V., Brugnera, R., Budjas, D., Caldwell, A., Cattadori, C., Chernogorov, A., Cossavella, F., Demidova, E. V., Denisov, A., Domula, A., Egorov, V., Falkenstein, R., Ferella, A. D., Freund, K., Froborg, F., Frodyma, N., Gangapshev, A., Garfagnini, A., Gazzana, S., Grambayr, P., Gurentsov, V., Gusev, K., Guthikonda, K. K., Hampel, W., Hegai, A., Heisel, M., Hemmer, S., Heusser, G., Hofmann, W., Hult, M., Inzhechik, L. V., Ioannucci, L., Csathy, J. Janicsko, Jochum, J., Junker, M., Kianovsky, S., Kirpichnikov, I. V., Kirsch, A., Klimenko, A., Knoepfle, K. T., Kochetov, O., Kornoukhov, V. N., Kusminov, V., Laubenstein, M., Lazzaro, A., Lebedev, V. I., Lehnert, B., Liao, H. Y., Lindner, M., Lippi, I., Liu, X., Lubashevskiy, A., Lubsandorzhiev, B., Lutter, G., Machado, A. A., Majorovits, B., Maneschg, W., Nemchenok, I., Nisi, S., O'Shaughnessy, C., Pandola, L., Pelczar, K., Peraro, L., Pullia, A., Riboldi, S., Ritter, F., Sada, C., Salathe, M., Schmitt, C., Schoenert, S., Schreiner, J., Schulz, O., Schwingenheuer, B., Shevchik, E., Shirchenko, M., Simgen, H., Smolnikov, A., Stanco, L., Strecker, H., Tarka, M., Ur, C. A., Vasenko, A. A., Volynets, O., von Sturm, K., Walter, M., Wegmann, A., Wojcik, M., Yanovich, E., Zavarise, P., Zhitnikov, I., Zhukov, S. V., Zinatulina, D., Zuber, K., and Zuzel, G.

Subjects
Physics, Nuclear and High Energy Physics, Range (particle radiation), Half-life, chemistry.chemical_element, FOS: Physical sciences, Germanium, Semiconductor detector, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), chemistry, Double beta decay, Liquid argon, Neutrino, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract

The primary goal of the GERmanium Detector Array (Gerda) experiment at the Laboratori Nazionali del Gran Sasso of INFN is the search for the neutrinoless double beta decay of Ge-76. High-purity germanium detectors made from material enriched in Ge-76 are operated directly immersed in liquid argon, allowing for a substantial reduction of the background with respect to predecessor experiments. The first 5.04 kg yr of data collected in Phase I of the experiment have been analyzed to measure the half-life of the neutrino-accompanied double beta decay of Ge-76. The observed spectrum in the energy range between 600 and 1800 keV is dominated by the double beta decay of Ge-76. The half-life extracted from Gerda data is T(1/2) = (1.84 +0.14 -0.10) 10^{21} yr., 14 pages, 2 figures, submitted to J. Phys. G: Nucl. Part. Phys

Published
2012

41. The GERDA experiment for the search of 0������ decay in ^{76}Ge

Author

GERDA Collaboration, Ackermann, K. -H., Agostini, M., Allardt, M., Altmann, M., Andreotti, E., Bakalyarov, A. M., Balata, M., Barabanov, I., Heider, M. Barnabe, Barros, N., Baudis, L., Bauer, C., Becerici-Schmidt, N., Bellotti, E., Belogurov, S., Belyaev, S. T., Benato, G., Bettini, A., Bezrukov, L., Bode, T., Brudanin, V., Brugnera, R., Budjas, D., Caldwell, A., Cattadori, C., Chernogorov, A., Chkvorets, O., Cossavella, F., D`Andragora, A., Demidova, E. V., Denisov, A., di Vacri, A., Domula, A., Egorov, V., Falkenstein, R., Ferella, A., Freund, K., Froborg, F., Frodyma, N., Gangapshev, A., Garfagnini, A., Gasparro, J., Gazzana, S., de Orduna, R. Gonzalez, Grabmayr, P., Gurentsov, V., Gusev, K., Guthikonda, K. K., Hampel, W., Hegai, A., Heisel, M., Hemmer, S., Heusser, G., Hofmann, W., Hult, M., Inzhechik, L. V., Ioannucci, L., Csalty, J. Janicsko, Jochum, J., Junker, M., Kankanyan, R., Kianovsky, S., Kihm, T., Kiko, J., Kirpichnikov, I. V., Kirsch, A., Klimenko, A., Knapp, M., Kn��pfle, K. T., Kochetov, O., Kornoukhov, V. N., Kr��ninger, K., Kusminov, V., Laubenstein, M., Lazzaro, A., Lebedev, V. I., Lehnert, B., Lenz, D., Liao, H., Lindner, M., Lippi, I., Liu, J., Liu, X., Lubashevskiy, A., Lubsandorzhiev, B., Machado, A. A., Majorovits, B., Maneschg, W., Marissens, G., Mayer, S., Meierhofer, G., Nemchenok, I., Niedermeier, L., Nisi, S., Oehm, J., O'Shaughnessy, C., Pandola, L., Peiffer, P., Pelczar, K., Pullia, A., Riboldi, S., Ritter, F., Alvarez, C. Rossi, Sada, C., Salathe, M., Schmitt, C., Sch��nert, S., Schreiner, J., Schubert, J., Schulz, O., Schwan, U., Schwingenheuer, B., Seitz, H., Shevchik, E., Shirchenko, M., Simgen, H., Smolnikov, A., Stanco, L., Stelzer, F., Strecker, H., Tarka, M., Trunk, U., Ur, C. A., Vasenko, A. A., Vogt, S., Volynets, O., von Sturm, K., Wagner, V., Walter, M., Wegmann, A., Wojcik, M., Yanovich, E., Zavarise, P., Zhitnikov, I., Zhukov, S. V., Zinatulina, D., Zuber, K., and Zuzel, G.

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

The GERDA collaboration is performing a search for neutrinoless double beta decay of ^{76}Ge with the eponymous detector. The experiment has been installed and commissioned at the Laboratori Nazionali del Gran Sasso and has started operation in November 2011. The design, construction and first operational results are described, along with detailed information from the R&D phase., 31 pages, 23 figures, submitted to EPJC

Published
2012
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42. Results of a search for 2��-decay of Xe-136 with high pressure copper proportional counters in Baksan Neutrino Observatory INR RAS

Author

Gavriljuk, Ju. M., Gangapshev, A. M., Kazalov, V. V., Kuzminov, V. V., Panasenko, S. I., Ratkevich, S. S., Zhantudueva, D. A., and Yakimenko, S. P.

Subjects
FOS: Physical sciences, Nuclear Experiment (nucl-ex)
Abstract

Search for ����-decay of Xe-136 with two high pressure proportional counters is carried out in Baksan Neutrino Observatory. The experiment is based on comparision of spectra measured with natural and enriched xenon. The measured halfe life is equal to T_{1/2}=5.5^{+4.6}_{-1.7} \cdot 10^{21} yr (67% C.L.) for ����2��-decay mode. No evidence has been found for neutrinoless ����-decay. The decay half life limit based on data measured during 17280 h is T_{1/2}(����0��)\geq 4.9 \cdot 10^{23} yr (90% C.L.)., 4 pages, 8 figure, proceedings for XV-th International School "Particles and Cosmology" May 26 - June 2, 2011 Troitsk, Moscow Region, Russian Federation

Published
2011
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43. Results of wavelet processing of the 2K-capture Kr-78 experiment statistics

Author

Gavrilyuk, Yu. M., Gangapshev, A. M., Kazalov, V. V., Kuzminov, V. V., Panasenko, S. I., and Ratkevich, S. S.

Subjects
FOS: Physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract

Results of a search for Kr-78 double K-capture with the large low-background proportional counter (2005-2008 years) at the Baksan Neutrino Observatory are presented. An experimental method and characteristics of detectors are described. Basic features of the digitized pulses processing using wavelet transform are considered. With due account taken of the analysis of individual noise characteristic it has been shown that the appropriate choice of both wavelet characteristics and sequence of processing algorithms allows one to decrease the background in the energy region of useful events with a unique set of characteristics by ~2000 times. New limit on the half-life of Kr-78 with regard to 2K-capture has been found: T_{1/2} >= 2.4E21 yrs (90% C.L.)., 12 pages, 9 figures

Published
2010

44. Pulse Shape Analysis and Identification of Multipoint Events in a Large-Volume Proportional Counter in an Experimental Search for 2K Capture Kr-78

Author

Yu. M. Gavrilyuk, A. M. Gangapshev, V. V. Kazalov, V. V. Kuz’minov, S. I. Panasenko, S. S. Ratkevich, and S. P. Yakimenko

Subjects
Physics, Signal processing, Physics - Instrumentation and Detectors, Detector, Proportional counter, FOS: Physical sciences, Charge (physics), Instrumentation and Detectors (physics.ins-det), Computational physics, Wavelet, Ionization, Sensitivity (control systems), Nuclear Experiment (nucl-ex), Instrumentation, Nuclear Experiment, Event (probability theory)
Abstract

A pulse shape analysis algorithm and a method for suppressing the noise component of signals from a large copper proportional counter in the experiment aimed at searching for 2K capture of Kr-78 are described. These signals correspond to a compound event with different numbers of charge clusters due to from primary ionization is formed by these signals. A technique for separating single- and multipoint events and determining the charge in individual clusters is presented. Using the Daubechies wavelets in multiresolutional signal analysis, it is possible to increase the sensitivity and the resolution in extraction of multipoint events in the detector by a factor of 3-4., 10 pages, 8 figures. submitted to Instruments and Experimental Techniques; ISSN 0020/4412

Published
2009

45. Comparative analysis of spectra of the background of the proportional counter filled with Kr, enriched in Kr-78, and with Kr of natural content

Author

Gavriljuk, Yu. M., Gavrin, V. N., Gangapshev, A. M., Kazalov, V. V., Kuzminov, V. V., Panasenko, S. I., and Ratkevich, S. S.

Subjects
FOS: Physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract

The results of the experiment searching for 2K-capture with large low-background proportional counter are presented. The comparison of spectra of the background of the proportional counter filled with Kr enriched in $^{78}$Kr (8400 hr) and with natural Kr (3039 hr) is given. A new limit on the half-life of $^{78}$Kr with regard to 2K-capture, T$_{1/2}\geq2.0\cdot10^{21}$ yrs (95% C.L.) has been obtained., Comment: 4 pages, 7 postscript figures, talk at the XIV-th Int. School "Particles and Cosmology"

Published
2007
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46. Results of a search for 2$��$-decay of $^{136}$Xe with high-pressure copper proportional counters in Baksan Neutrino Observatory

Author

Gavriljuk, Ju. M., Gangapshev, A. M., Kuzminov, V. V., Panasenko, S. I., and Ratkevich, S. S.

Subjects
FOS: Physical sciences, Nuclear Experiment (nucl-ex)
Abstract

The experiment for the 2$��$-decay of $^{136}$Xe search with two high-pressure copper proportional counters has been held in Baksan neutrino observatory. The search for the process is based on comparison of spectra measured with natural and enriched xenon. No evidence has been found for 2$��$(2$��$)- and 2$��$(0$��$)-decay. The decay half lifetime limit based on data measured during 8000 h is T$_{1/2}$$\geq8.5\cdot10^{21}$yr for 2$��$-mode and T$_{1/2}$$\geq3.1\cdot10^{23}$yr for 0$��$-mode (90%C.L.)., 9 pages, 8 figures; talk at the NANP'05 Conference; submitted to Phys. At. Nucl

Published
2005
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47. Next stage of search for 2K(2$��$)-capture of $^{78}$Kr

Author

Gavriljuk, Ju. M., Gavrin, V. N., Gangapshev, A. M., Kazalov, V. V., Kuzminov, V. V., Osetrova, N. Ya., Pul'nikov, I. I., Ryabukhin, A. V., Shubin, A. N., Skorynin, G. M., Panasenko, S. I., and Ratkevich, S. S.

Subjects
FOS: Physical sciences, Nuclear Experiment (nucl-ex)
Abstract

A technique to search for 2K-capture of $^{78}$Kr with large low-background proportional counter filled with an enriched in $^{78}$Kr up to 99.8% sample of Krypton at a pressure of 4.51 is described in this paper. The results of first measurements are presented. Analysis of data collected during 159 hours yielded new limit to the half-life of $^{78}$Kr with regard to 2K-capture (T$_{1/2}\geq6\cdot10^{21}$ yr (90% C.L.)). Sensitivity of the facility to the process for one year of measurement was evaluated to be $\texttt{S}=1.0\cdot10^{22}$ yr (90% C.L.)., 4 pages, 5 figures; talk at the NANP'05 Conference; submitted to Phys. At. Nucl

Published
2005
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48. Characteristics of proportional counter filled with CF$_4$ and Xe additions

Author

Gavriljuk, Ju. M., Gangapshev, A. M., Kuzminov, V. V., Osetrova, N. Ya., Panasenko, S. I., and Ratkevich, S. S.

Subjects
FOS: Physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract

In this article the measurement results of proportional counter working characteristics filled with CF$_4$ and Xe ($0\div5$% Xe) additions at different pressures ($0.8\div14.8$ $at$) are presented. We have found that a bit of Xe addition reduces working voltage necessary to get the same gas amplification by two times against pure CF$_4$, it improves as well the resolution of the counter and increases limit gas amplification by more than ten times., 7 pages, 8 figures

Published
2002

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