Search

Your search keyword '"Chan, Y-D."' showing total 606 results
Start Over Author "Chan, Y-D."
606 results on '"Chan, Y-D."'

1. Final Results of the MAJORANA DEMONSTRATOR's Search for Double-Beta Decay of $^{76}$Ge to Excited States of $^{76}$Se

Author

Arnquist, I. J., Avignone III, F. T., Barabash, A. S., Blalock, E., Bos, B., Busch, M., Chan, Y. -D., Chapman, J. R., Christofferson, C. D., Chu, P. -H., Cuesta, C., Detwiler, J. A., Efremenko, Yu., Ejiri, H., Elliott, S. R., Fuad, N., Giovanetti, G. K., Green, M. P., Gruszko, J., Guinn, I. S., Guiseppe, V. E., Haufe, C. R., Henning, R., Aguilar, D. Hervas, Hoppe, E. W., Kim, I., Kouzes, R. T., Lannen V, T. E., Li, A., Massarczyk, R., Meijer, S. J., Oli, T. K., Paudel, L. S., Pettus, W., Poon, A. W. P., Radford, D. C., Reine, A. L., Rielage, K., Schaper, D. C., Schleich, S. J., Tedeschi, D., Varner, R. L., Vasilyev, S., Watkins, S. L., Wilkerson, J. F., Wiseman, C., Yu, C. -H., and Zhu, B. X.

Subjects
Nuclear Experiment
Abstract

$^{76}$Ge can $\beta\beta$ decay into three possible excited states of $^{76}$Se, with the emission of two or, if the neutrino is Majorana, zero neutrinos. None of these six transitions have yet been observed. The MAJORANA DEMONSTRATOR was designed to study $\beta\beta$ decay of $^{76}$Ge using a low background array of high purity germanium detectors. With 98.2 kg-y of isotopic exposure, the DEMONSTRATOR sets the strongest half-life limits to date for all six transition modes. For $2\nu\beta\beta$ to the $0^+_1$ state of $^{76}$Se, this search has begun to probe for the first time half-life values predicted using modern many-body nuclear theory techniques, setting a limit of $T_{1/2}>1.5\times10^{24}$ y (90% CL)., Comment: 8 pages, 3 figures

Published
2024

2. An assay-based background projection for the MAJORANA DEMONSTRATOR using Monte Carlo Uncertainty Propagation

Author

Arnquist, I. J., Avignone III, F. T., Barabash, A. S., Barton, C. J., Bhimani, K. H., Blalock, E., Bos, B., Busch, M., Caldwell, T. S., Chan, Y. -D., Christofferson, C. D., Chu, P. -H., Clark, M. L., Cuesta, C., Detwiler, J. A., Efremenko, Yu., Ejiri, H., Elliott, S. R., Fuad, N., Giovanetti, G. K., Green, M. P., Gruszko, J., Guinn, I. S., Guiseppe, V. E., Haufe, C. R., Henning, R., Aguilar, D. Hervas, Hoppe, E. W., Hostiuc, A., Kidd, M. F., Kim, I., Kouzes, R. T., Lannen V, T. E., Li, A., López-Castaño, J. M., Martin, R. D., Massarczyk, R., Meijer, S. J., Oli, T. K., Paudel, L. S., Pettus, W., Poon, A. W. P., Radford, D. C., Reine, A. L., Rielage, K., Ruof, N. W., Schaper, D. C., Schleich, S. J., Tedeschi, D., Varner, R. L., Vasilyev, S., Watkins, S. L., Wilkerson, J. F., Wiseman, C., Xu, W., and Yu, C. -H.

Subjects
Nuclear Experiment, Physics - Instrumentation and Detectors
Abstract

The background index is an important quantity which is used in projecting and calculating the half-life sensitivity of neutrinoless double-beta decay ($0\nu\beta\beta$) experiments. A novel analysis framework is presented to calculate the background index using the specific activities, masses and simulated efficiencies of an experiment's components as distributions. This Bayesian framework includes a unified approach to combine specific activities from assay. Monte Carlo uncertainty propagation is used to build a background index distribution from the specific activity, mass and efficiency distributions. This analysis method is applied to the MAJORANA DEMONSTRATOR, which deployed arrays of high-purity Ge detectors enriched in $^{76}$Ge to search for $0\nu\beta\beta$. The framework projects a mean background index of $\left[8.95 \pm 0.36\right] \times 10^{-4}$cts/(keV kg yr) from $^{232}$Th and $^{238}$U in the DEMONSTRATOR's components., Comment: 9 pages, 3 figures

Published
2024

3. Search for charge non-conservation and Pauli exclusion principle violation with the Majorana Demonstrator

Author

Arnquist, IJ, Avignone, FT, Barabash, AS, Barton, CJ, Bhimani, KH, Blalock, E, Bos, B, Busch, M, Buuck, M, Caldwell, TS, Chan, Y-D, Christofferson, CD, Chu, P-H, Clark, ML, Cuesta, C, Detwiler, JA, Efremenko, Yu, Ejiri, H, Elliott, SR, Giovanetti, GK, Green, MP, Gruszko, J, Guinn, IS, Guiseppe, VE, Haufe, CR, Henning, R, Aguilar, D Hervas, Hoppe, EW, Hostiuc, A, Kidd, MF, Kim, I, Lannen V, RT, Lannen, IE, Li, A, Lopez-Castano, JM, Martin, EL, Martin, RD, Massarczyk, R, Meijer, SJ, Oli, TK, Paudel, LS, Pettus, W, Poon, AWP, Radford, DC, Reine, AL, Rielage, K, Ruof, NW, Schaper, DC, Tedeschi, D, Varner, RL, Vasilyev, S, Wilkerson, JF, Wiseman, C, Xu, W, Yu, C-H, and Zhu, BX

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Mathematical Sciences, Fluids & Plasmas, Mathematical sciences, Physical sciences
Abstract

Charge conservation and the Pauli exclusion principle result from fundamental symmetries in the standard model of particle physics, and are typically taken as axiomatic. High-precision tests for small violations of these symmetries could point to new physics. Here we consider three models for violation of these processes, which would produce detectable ionization in the high-purity germanium detectors of the Majorana Demonstrator experiment. Using a 37.5 kg yr exposure, we report a lower limit on the electron mean lifetime, improving the previous best limit for the e→νeνe¯νe decay channel by more than an order of magnitude. We also present searches for two types of violation of the Pauli exclusion principle, setting limits on the probability of an electron to be found in a symmetric quantum state.

Published
2024

4. Exotic Dark Matter Search with the Majorana Demonstrator

Author

Arnquist, IJ, Avignone, FT, Barabash, AS, Barton, CJ, Bhimani, KH, Blalock, E, Bos, B, Busch, M, Buuck, M, Caldwell, TS, Chan, Y-D, Christofferson, CD, Chu, P-H, Clark, ML, Cuesta, C, Detwiler, JA, Efremenko, Yu, Ejiri, H, Elliott, SR, Giovanetti, GK, Green, MP, Gruszko, J, Guinn, IS, Guiseppe, VE, Haufe, CR, Henning, R, Hervas Aguilar, D, Hoppe, EW, Hostiuc, A, Kidd, MF, Kim, I, Kouzes, RT, Lannen V, TE, Li, A, Lopez, AM, López-Castaño, JM, Martin, EL, Martin, RD, Massarczyk, R, Meijer, SJ, Mertens, S, Oli, TK, Othman, G, Paudel, LS, Pettus, W, Poon, AWP, Radford, DC, Rager, J, Reine, AL, Rielage, K, Ruof, NW, Schaper, DC, Tedeschi, D, Varner, RL, Vasilyev, S, Wilkerson, JF, Wiseman, C, Xu, W, Yu, C-H, and Zhu, BX

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Majorana Collaboration, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract

With excellent energy resolution and ultralow-level radiogenic backgrounds, the high-purity germanium detectors in the Majorana Demonstrator enable searches for several classes of exotic dark matter (DM) models. In this work, we report new experimental limits on keV-scale sterile neutrino DM via the transition magnetic moment from conversion to active neutrinos ν_{s}→ν_{a}. We report new limits on fermionic dark matter absorption (χ+A→ν+A) and sub-GeV DM-nucleus 3→2 scattering (χ+χ+A→ϕ+A), and new exclusion limits for bosonic dark matter (axionlike particles and dark photons). These searches utilize the (1-100)-keV low-energy region of a 37.5-kg y exposure collected by the Demonstrator between May 2016 and November 2019 using a set of ^{76}Ge-enriched detectors whose surface exposure time was carefully controlled, resulting in extremely low levels of cosmogenic activation.

Published
2024

5. Majorana Demonstrator Data Release for AI/ML Applications

Author

Arnquist, I. J., Avignone III, F. T., Barabash, A. S., Barton, C. J., Bhimani, K. H., Blalock, E., Bos, B., Busch, M., Buuck, M., Caldwell, T. S., Chan, Y. -D., Christofferson, C. D., Chu, P. -H., Clark, M. L., Cuesta, C., Detwiler, J. A., Efremenko, Yu., Ejiri, H., Elliott, S. R., Fuad, N., Giovanetti, G. K., Green, M. P., Gruszko, J., Guinn, I. S., Guiseppe, V. E., Haufe, C. R., Henning, R., Aguilar, D. Hervas, Hoppe, E. W., Hostiuc, A., Kidd, M. F., Kim, I., Kouzes, R. T., Lannen V, T. E., Li, A., Lopez-Castano, J. M., Martin, R. D., Massarczyk, R., Meijer, S. J., Mertens, S., Oli, T. K., Paudel, L. S., Pettus, W., Poon, A. W. P., Quenallata, B., Radford, D. C., Reine, A. L., Rielage, K., Ruof, N. W., Schaper, D. C., Schleich, S. J., Tedeschi, D., Varner, R. L., Vasilyev, S., Watkins, S. L., Wilkerson, J. F., Wiseman, C., Xu, W., Yu, C. -H., and Zhu, B. X.

Subjects
Computer Science - Machine Learning, Nuclear Experiment, Physics - Data Analysis, Statistics and Probability, Physics - Instrumentation and Detectors
Abstract

The enclosed data release consists of a subset of the calibration data from the Majorana Demonstrator experiment. Each Majorana event is accompanied by raw Germanium detector waveforms, pulse shape discrimination cuts, and calibrated final energies, all shared in an HDF5 file format along with relevant metadata. This release is specifically designed to support the training and testing of Artificial Intelligence (AI) and Machine Learning (ML) algorithms upon our data. This document is structured as follows. Section I provides an overview of the dataset's content and format; Section II outlines the location of this dataset and the method for accessing it; Section III presents the NPML Machine Learning Challenge associated with this dataset; Section IV contains a disclaimer from the Majorana collaboration regarding the use of this dataset; Appendix A contains technical details of this data release. Please direct questions about the material provided within this release to liaobo77@ucsd.edu (A. Li)., Comment: DataPlanet Access: https://dataplanet.ucsd.edu/dataset.xhtml?persistentId=perma:83.ucsddata/UQWQAV

Published
2023

6. Energy Calibration of Germanium Detectors for the MAJORANA DEMONSTRATOR

Author

Arnquist, I. J., Avignone III, F. T., Barabash, A. S., Barton, C. J., Bhimani, K. H., Blalock, E., Bos, B., Busch, M., Buuck, M., Caldwell, T. S., Chan, Y-D., Christofferson, C. D., Chu, P. -H., Clark, M. L., Cuesta, C., Detwiler, J. A., Efremenko, Yu., Ejiri, H., Elliott, S. R., Giovanetti, G. K., Green, M. P., Gruszko, J., Guinn, I. S., Guiseppe, V. E., Haufe, C. R., Henning, R., Aguilar, D. Hervas, Hoppe, E. W., Hostiuc, A., Kidd, M. F., Kim, I., Kouzes, R. T., Lannen V, T. E., Li, A., López-Castaño, J. M., Martin, E. L., Martin, R. D., Massarczyk, R., Meijer, S. J., Oli, T. K., Paudel, L. S., Pettus, W., Poon, A. W. P., Radford, D. C., Reine, A. L., Rielage, K., Ruof, N. W., Schaper, D. C., Tedeschi, D., Varner, R. L., Vasilyev, S., Wilkerson, J. F., Wiseman, C., Xu, W., Yu, C. -H., and Zhu, B. X.

Subjects
Physics - Instrumentation and Detectors, Nuclear Experiment
Abstract

The MAJORANA DEMONSTRATOR was a search for neutrinoless double-beta decay ($0\nu\beta\beta$) in the $^{76}$Ge isotope. It was staged at the 4850-foot level of the Sanford Underground Research Facility (SURF) in Lead, SD. The experiment consisted of 58 germanium detectors housed in a low background shield and was calibrated once per week by deploying a $^{228}$Th line source for 1 to 2 hours. The energy scale calibration determination for the detector array was automated using custom analysis tools. We describe the offline procedure for calibration of the Demonstrator germanium detectors, including the simultaneous fitting of multiple spectral peaks, estimation of energy scale uncertainties, and the automation of the calibration procedure.

Published
2023
Full Text
View/download PDF

7. Modeling backgrounds for the Majorana Demonstrator

Author

Haufe, CR, Arnquist, IJ, Avignone, FT, Barabash, AS, Barton, CJ, Bhimani, KH, Blalock, E, Bos, B, Busch, M, Buuck, M, Caldwell, TS, Chan, Y-D, Christofferson, CD, Chu, P-H, Clark, ML, Cuesta, C, Detwiler, JA, Efremenko, Yu, Ejiri, H, Elliott, SR, Giovanetti, GK, Green, MP, Gruszko, J, Guinn, IS, Guiseppe, VE, Henning, R, Aguilar, D Hervas, Hoppe, EW, Hostiuc, A, Kidd, MF, Kim, I, Kouzes, RT, V., TE Lannen, Li, A, Lopez, AM, López-Castaño, JM, Martin, EL, Martin, RD, Massarczyk, R, Meijer, SJ, Oli, TK, Othman, G, Paudel, LS, Pettus, W, Poon, AWP, Radford, DC, Reine, AL, Rielage, K, Ruof, NW, Schaper, DC, Tedeschi, D, Varner, RL, Vasilyev, S, Wilkerson, JF, Wiseman, C, Xu, W, Yu, C-H, and Zhu, BX

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences
Abstract

The MAJORANA DEMONSTRATOR is a neutrinoless double-beta decay (0νββ) experiment containing ~30 kg of p-type point-contact germanium detectors enriched to 88% in 76Ge and ~14 kg of natural germanium detectors. The detectors are housed in two electroformed copper cryostats and surrounded by a graded passive shield with an active muon veto. An extensive radioassay campaign was performed prior to installation to insure the use of ultra-clean materials. The DEMONSTRATOR achieved one of the lowest background rates in the region of the 0νββ Q-value, 15.7±1.4 cts/(FWHM t y) from the low-background configuration spanning most of the 64.5 kg-yr active exposure. Nevertheless this background rate is a factor of five higher than the projected background rate. This discrepancy arises from an excess of events from the 232Th decay chain. Background-model fits aim to explain the deviation from assay-based projections, potentially determine the source(s) of observed backgrounds, and allow a precise measurement of the two-neutrino double-beta decay half-life. The fits agree with earlier simulation studies, which indicate the origin of the 232Th excess is not from a near-detector component and have informed design decisions for the next-generation LEGEND experiment. Recent findings have narrowed the suspected locations for the excess activity, motivating a final simulation and assay campaign to complete the background model.

Published
2023

8. Energy calibration of germanium detectors for the Majorana Demonstrator

Author

Arnquist, IJ, Avignone, FT, Barabash, AS, Barton, CJ, Bhimani, KH, Blalock, E, Bos, B, Busch, M, Buuck, M, Caldwell, TS, Chan, Y-D, Christofferson, CD, Chu, P-H, Clark, ML, Cuesta, C, Detwiler, JA, Efremenko, Yu, Ejiri, H, Elliott, SR, Giovanetti, GK, Green, MP, Gruszko, J, Guinn, IS, Guiseppe, VE, Haufe, CR, Henning, R, Aguilar, D Hervas, Hoppe, EW, Hostiuc, A, Kidd, MF, Kim, I, Kouzes, RT, Lannen, TE, Li, A, López-Castaño, JM, Martin, EL, Martin, RD, Massarczyk, R, Meijer, SJ, Oli, TK, Paudel, LS, Pettus, W, Poon, AWP, Radford, DC, Reine, AL, Rielage, K, Ruof, NW, Schaper, DC, Tedeschi, D, Varner, RL, Vasilyev, S, Wilkerson, JF, Wiseman, C, Xu, W, Yu, C-H, Zhu, BX, and collaboration, The Majorana

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, Analysis and statistical methods, Double-beta decay detectors, Pattern recognition, cluster finding, calibration and fitting methods, Gamma detectors, Engineering, Nuclear & Particles Physics, Physical sciences
Abstract

The Majorana Demonstrator was a search for neutrinoless double-beta decay (0νββ) in the 76Ge isotope. It was staged at the 4850-foot level of the Sanford Underground Research Facility (SURF) in Lead, SD. The experiment consisted of 58 germanium detectors housed in a low background shield and was calibrated once per week by deploying a 228Th line source for 1 to 2 hours. The energy scale calibration determination for the detector array was automated using custom analysis tools. We describe the offline procedure for calibration of the Demonstrator germanium detectors, including the simultaneous fitting of multiple spectral peaks, estimation of energy scale uncertainties, and the automation of the calibration procedure.

Published
2023

9. Erratum: Search for Spontaneous Radiation from Wave Function Collapse in the Majorana Demonstrator [Phys. Rev. Lett. 129, 080401 (2022)]

Author

Arnquist, IJ, Avignone, FT, Barabash, AS, Barton, CJ, Bhimani, KH, Blalock, E, Bos, B, Busch, M, Buuck, M, Caldwell, TS, Chan, Y-D, Christofferson, CD, Chu, P-H, Clark, ML, Cuesta, C, Detwiler, JA, Efremenko, Yu, Ejiri, H, Elliott, SR, Giovanetti, GK, Green, MP, Gruszko, J, Guinn, IS, Guiseppe, VE, Haufe, CR, Henning, R, Hervas Aguilar, D, Hoppe, EW, Hostiuc, A, Kim, I, Kouzes, RT, Lannen V, TE, Li, A, Lopez, AM, López-Castaño, JM, Martin, EL, Martin, RD, Massarczyk, R, Meijer, SJ, Oli, TK, Othman, G, Paudel, LS, Pettus, W, Poon, AWP, Radford, DC, Reine, AL, Rielage, K, Ruof, NW, Tedeschi, D, Varner, RL, Vasilyev, S, Wilkerson, JF, Wiseman, C, Xu, W, Yu, C-H, and Zhu, BX

Subjects
Quantum Physics, Physical Sciences, Majorana Collaboration, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract

This corrects the article DOI: 10.1103/PhysRevLett.129.080401.

Published
2023

10. Charge trapping correction and energy performance of the Majorana Demonstrator

Author

Arnquist, IJ, Avignone, FT, Barabash, AS, Barton, CJ, Bhimani, KH, Blalock, E, Bos, B, Busch, M, Buuck, M, Caldwell, TS, Chan, Y-D, Christofferson, CD, Chu, P-H, Clark, ML, Cuesta, C, Detwiler, JA, Efremenko, Yu, Ejiri, H, Elliott, SR, Giovanetti, GK, Green, MP, Gruszko, J, Guinn, IS, Guiseppe, VE, Haufe, CR, Henning, R, Aguilar, D Hervas, Hoppe, EW, Hostiuc, A, Kidd, MF, Kim, I, Kouzes, RT, V., TE Lannen, Li, A, López-Castaño, JM, Martin, EL, Martin, RD, Massarczyk, R, Meijer, SJ, Mertens, S, Oli, TK, Othman, G, Paudel, LS, Pettus, W, Poon, AWP, Radford, DC, Reine, AL, Rielage, K, Ruof, NW, Schaper, DC, Tedeschi, D, Varner, RL, Vasilyev, S, Wilkerson, JF, Wiseman, C, Xu, W, Yu, C-H, and Zhu, BX

Subjects
Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, Affordable and Clean Energy, Nuclear and plasma physics
Abstract

P-type point contact (PPC) high-purity germanium detectors are an important technology in astroparticle and nuclear physics due to their superb energy resolution, low noise, and pulse shape discrimination capabilities. Analysis of data from the Majorana Demonstrator, a neutrinoless double-β decay experiment deploying PPC detectors enriched in Ge76, has led to several novel improvements in the analysis of PPC signals. In this work we discuss charge trapping in PPC detectors and its effect on energy resolution. Small dislocations or impurities in the crystal lattice result in trapping of charge carriers from an ionization event of interest, attenuating the signal, and degrading the measured energy. We present a modified digital pole-zero correction to the signal energy estimation that counters the effects of charge trapping and improves the energy resolution of the Majorana Demonstrator by approximately 30% to around 2.4 keV full width at half-maximum at 2039 keV, the Ge76 Q value. An alternative approach achieving similar resolution enhancement is also presented.

Published
2023

11. Modeling Backgrounds for the MAJORANA DEMONSTRATOR

Author

Haufe, C. R., Arnquist, I. J., Avignone III, F. T., Barabash, A. S., Barton, C. J., Bhimani, K. H., Blalock, E., Bos, B., Busch, M., Buuck, M., Caldwell, T. S., Chan, Y-D., Christofferson, C. D., Chu, P. -H., Clark, M. L., Cuesta, C., Detwiler, J. A., Efremenko, Yu., Ejiri, H., Elliott, S. R., Giovanetti, G. K., Green, M. P., Gruszko, J., Guinn, I. S., Guiseppe, V. E., Henning, R., Aguilar, D. Hervas, Hoppe, E. W., Hostiuc, A., Kidd, M. F., Kim, I., Kouzes, R. T., Lannen V, T. E., Li, A., Lopez, A. M., López-Castaño, J. M., Martin, E. L., Martin, R. D., Massarczyk, R., Meijer, S. J., Oli, T. K., Othman, G., Paudel, L. S., Pettus, W., Poon, A. W. P., Radford, D. C., Reine, A. L., Rielage, K., Ruof, N. W., Schaper, D. C., Tedeschi, D., Varner, R. L., Vasilyev, S., Wilkerson, J. F., Wiseman, C., Xu, W., Yu, C. -H., and Zhu, B. X.

Subjects
Nuclear Experiment
Abstract

The MAJORANA DEMONSTRATOR is a neutrinoless double-beta decay ($0\nu\beta\beta$) experiment containing $\sim$30 kg of p-type point contact germanium detectors enriched to 88% in 76Ge and $\sim$14 kg of natural germanium detectors. The detectors are housed in two electroformed copper cryostats and surrounded by a graded passive shield with active muon veto. An extensive radioassay campaign was performed prior to installation to insure the use of ultra-clean materials. The DEMONSTRATOR achieved one of the lowest background rates in the region of the $0\nu\beta\beta$ Q-value, 15.7 $\pm$ 1.4 cts/(FWHM t y) from the low-background configuration spanning most of the 64.5 kg-yr active exposure. Nevertheless this background rate is a factor of five higher than the projected background rate. This discrepancy arises from an excess of events from the 232Th decay chain. Background model fits aim to understand this deviation from assay-based projections, potentially determine the source(s) of observed backgrounds, and allow a precision measurement of the two-neutrino double-beta decay half-life. The fits agree with earlier simulation studies, which indicate the origin of the 232Th excess is not from a near-detector component and have informed design decisions for the next-generation LEGEND experiment. Recent findings have narrowed the suspected locations for the excess activity, motivating a final simulation and assay campaign to complete the background model., Comment: 8 pages, 6 figures, Proceedings from the Low Radioactivity Techniques Workshop 2022 in Rapid City, SD, USA

Published
2022

12. Charge Trapping and Energy Performance of the MAJORANA DEMONSTRATOR

Author

Arnquist, I. J., Avignone III, F. T., Barabash, A. S., Barton, C. J., Bhimani, K. H., Blalock, E., Bos, B., Busch, M., Buuck, M., Caldwell, T. S., Chan, Y-D., Christofferson, C. D., Chu, P. -H., Clark, M. L., Cuesta, C., Detwiler, J. A., Efremenko, Yu., Ejiri, H., Elliott, S. R., Giovanetti, G. K., Green, M. P., Gruszko, J., Guinn, I. S., Guiseppe, V. E., Haufe, C. R., Henning, R., Aguilar, D. Hervas, Hoppe, E. W., Hostiuc, A., Kidd, M. F., Kim, I., Kouzes, R. T., Lannen V, T. E., Li, A., López-Castaño, J. M., Martin, E. L., Martin, R. D., Massarczyk, R., Meijer, S. J., Mertens, S., Oli, T. K., Othman, G., Paudel, L. S., Pettus, W., Poon, A. W. P., Radford, D. C., Reine, A. L., Rielage, K., Ruof, N. W., Schaper, D. C., Tedeschi, D., Varner, R. L., Vasilyev, S., Wilkerson, J. F., Wiseman, C., Xu, W., Yu, C. -H., and Zhu, B. X.

Subjects
Physics - Instrumentation and Detectors
Abstract

P-type point contact (PPC) high-purity germanium detectors are an important technology in astroparticle and nuclear physics due to their superb energy resolution, low noise, and pulse shape discrimination capabilities. Analysis of data from the MAJORANA DEMONSTRATOR, a neutrinoless double-beta decay experiment deploying PPC detectors enriched in $^{76}$Ge, has led to several novel improvements in the analysis of PPC signals. In this work we discuss charge trapping in PPC detectors and its effect on energy resolution. Small dislocations or impurities in the crystal lattice result in trapping of charge carriers from an ionization event of interest, attenuating the signal and degrading the measured energy. We present a modified digital pole-zero correction to the signal energy estimation that counters the effects of charge trapping and improves the energy resolution of the MAJORANA DEMONSTRATOR by approximately 30% to around 2.4 keV FWHM at 2039 keV, the $^{76}$Ge $Q$-value. An alternative approach achieving similar resolution enhancement is also presented., Comment: 12 pages, 13 figures

Published
2022
Full Text
View/download PDF

13. Interpretable Boosted Decision Tree Analysis for the Majorana Demonstrator

Author

Arnquist, I. J., Avignone III, F. T., Barabash, A. S., Barton, C. J., Bhimani, K. H., Blalock, E., Bos, B., Busch, M., Buuck, M., Caldwell, T. S., Chan, Y -D., Christofferson, C. D., Chu, P. -H., Clark, M. L., Cuesta, C., Detwiler, J. A., Efremenko, Yu., Elliott, S. R., Giovanetti, G. K., Green, M. P., Gruszko, J., Guinn, I. S., Guiseppe, V. E., Haufe, C. R., Henning, R., Aguilar, D. Hervas, Hoppe, E. W., Hostiuc, A., Kidd, M. F., Kim, I., Kouzes, R. T., Lannen V, T. E., Li, A., Lopez-Castano, J. M., Martin, E. L., Martin, R. D., Massarczyk, R., Meijer, S. J., Oli, T. K., Othman, G., Paudel, L. S., Pettus, W., Poon, A. W. P., Radford, D. C., Reine, A. L., Rielage, K., Ruof, N. W., Schaper, D. C., Tedeschi, D., Varner, R. L., Vasilyev, S., Wilkerson, J. F., Wiseman, C., Xu, W., and Yu, C. -H.

Subjects
Physics - Data Analysis, Statistics and Probability, Computer Science - Machine Learning, Nuclear Experiment
Abstract

The Majorana Demonstrator is a leading experiment searching for neutrinoless double-beta decay with high purity germanium detectors (HPGe). Machine learning provides a new way to maximize the amount of information provided by these detectors, but the data-driven nature makes it less interpretable compared to traditional analysis. An interpretability study reveals the machine's decision-making logic, allowing us to learn from the machine to feedback to the traditional analysis. In this work, we have presented the first machine learning analysis of the data from the Majorana Demonstrator; this is also the first interpretable machine learning analysis of any germanium detector experiment. Two gradient boosted decision tree models are trained to learn from the data, and a game-theory-based model interpretability study is conducted to understand the origin of the classification power. By learning from data, this analysis recognizes the correlations among reconstruction parameters to further enhance the background rejection performance. By learning from the machine, this analysis reveals the importance of new background categories to reciprocally benefit the standard Majorana analysis. This model is highly compatible with next-generation germanium detector experiments like LEGEND since it can be simultaneously trained on a large number of detectors., Comment: 13 pages, 9 figures

Published
2022
Full Text
View/download PDF

14. Final Result of the MAJORANA DEMONSTRATOR's Search for Neutrinoless Double-$\beta$ Decay in $^{76}$Ge

Author

Arnquist, I. J., Avignone III, F. T., Barabash, A. S., Barton, C. J., Barton, P. J., Bhimani, K. H., Blalock, E., Bos, B., Busch, M., Buuck, M., Caldwell, T. S., Chan, Y-D., Christofferson, C. D., Chu, P. -H., Clark, M. L., Cuesta, C., Detwiler, J. A., Efremenko, Yu., Ejiri, H., Elliott, S. R., Giovanetti, G. K., Green, M. P., Gruszko, J., Guinn, I. S., Guiseppe, V. E., Haufe, C. R., Henning, R., Aguilar, D. Hervas, Hoppe, E. W., Hostiuc, A., Kidd, M. F., Kim, I., Kouzes, R. T., Lannen V, T. E., Li, A., Lopez, A. M., López-Castaño, J. M., Martin, E. L., Martin, R. D., Massarczyk, R., Meijer, S. J., Mertens, S., Oli, T. K., Othman, G., Paudel, L. S., Pettus, W., Poon, A. W. P., Radford, D. C., Reine, A. L., Rielage, K., Ruof, N. W., Schaper, D. C., Tedeschi, D., Varner, R. L., Vasilyev, S., Wilkerson, J. F., Wiseman, C., Xu, W., Yu, C. -H., and Zhu, B. X.

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

The MAJORANA DEMONSTRATOR searched for neutrinoless double-$\beta$ decay ($0\nu\beta\beta$) of $^{76}$Ge using modular arrays of high-purity Ge detectors operated in vacuum cryostats in a low-background shield. The arrays operated with up to 40.4 kg of detectors (27.2 kg enriched to $\sim$88\% in $^{76}$Ge). From these measurements, the DEMONSTRATOR has accumulated 64.5 kg yr of enriched active exposure. With a world-leading energy resolution of 2.52 keV FWHM at the 2039 keV $Q_{\beta\beta}$ (0.12\%), we set a half-life limit of $0\nu\beta\beta$ in $^{76}$Ge at $T_{1/2}>8.3\times10^{25}$ yr (90\% C.L.). This provides a range of upper limits on $m_{\beta\beta}$ of $(113-269)$ meV (90\% C.L.), depending on the choice of nuclear matrix elements., Comment: 8 pages, 2 figures

Published
2022
Full Text
View/download PDF

15. Final Result of the Majorana Demonstrator’s Search for Neutrinoless Double-β Decay in Ge76

Author

Arnquist, IJ, Avignone, FT, Barabash, AS, Barton, CJ, Barton, PJ, Bhimani, KH, Blalock, E, Bos, B, Busch, M, Buuck, M, Caldwell, TS, Chan, Y-D, Christofferson, CD, Chu, P-H, Clark, ML, Cuesta, C, Detwiler, JA, Efremenko, Yu, Ejiri, H, Elliott, SR, Giovanetti, GK, Green, MP, Gruszko, J, Guinn, IS, Guiseppe, VE, Haufe, CR, Henning, R, Hervas Aguilar, D, Hoppe, EW, Hostiuc, A, Kidd, MF, Kim, I, Kouzes, RT, Lannen V, TE, Li, A, Lopez, AM, López-Castaño, JM, Martin, EL, Martin, RD, Massarczyk, R, Meijer, SJ, Mertens, S, Oli, TK, Othman, G, Paudel, LS, Pettus, W, Poon, AWP, Radford, DC, Reine, AL, Rielage, K, Ruof, NW, Schaper, DC, Tedeschi, D, Varner, RL, Vasilyev, S, Wilkerson, JF, Wiseman, C, Xu, W, Yu, C-H, and Zhu, BX

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, Majorana Collaboration, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract

The Majorana Demonstrator searched for neutrinoless double-β decay (0νββ) of ^{76}Ge using modular arrays of high-purity Ge detectors operated in vacuum cryostats in a low-background shield. The arrays operated with up to 40.4 kg of detectors (27.2 kg enriched to ∼88% in ^{76}Ge). From these measurements, the Demonstrator has accumulated 64.5 kg yr of enriched active exposure. With a world-leading energy resolution of 2.52 keV FWHM at the 2039 keV Q_{ββ} (0.12%), we set a half-life limit of 0νββ in ^{76}Ge at T_{1/2}>8.3×10^{25}  yr (90% C.L.). This provides a range of upper limits on m_{ββ} of (113-269) meV (90% C.L.), depending on the choice of nuclear matrix elements.

Published
2023

16. Interpretable boosted-decision-tree analysis for the Majorana Demonstrator

Author

Arnquist, IJ, Avignone, FT, Barabash, AS, Barton, CJ, Bhimani, KH, Blalock, E, Bos, B, Busch, M, Buuck, M, Caldwell, TS, Chan, Y-D, Christofferson, CD, Chu, P-H, Clark, ML, Cuesta, C, Detwiler, JA, Efremenko, Yu, Elliott, SR, Giovanetti, GK, Green, MP, Gruszko, J, Guinn, IS, Guiseppe, VE, Haufe, CR, Henning, R, Aguilar, D Hervas, Hoppe, EW, Hostiuc, A, Kidd, MF, Kim, I, Kouzes, RT, V., TE Lannen, Li, A, López-Castaño, JM, Martin, EL, Martin, RD, Massarczyk, R, Meijer, SJ, Oli, TK, Othman, G, Paudel, LS, Pettus, W, Poon, AWP, Radford, DC, Reine, AL, Rielage, K, Ruof, NW, Schaper, DC, Tedeschi, D, Varner, RL, Vasilyev, S, Wilkerson, JF, Wiseman, C, Xu, W, and Yu, C-H

Subjects
Nuclear and Plasma Physics, Physical Sciences, Nuclear and plasma physics
Abstract

The Majorana Demonstrator is a leading experiment searching for neutrinoless double-beta decay with high purity germanium (HPGe) detectors. Machine learning provides a new way to maximize the amount of information provided by these detectors, but the data-driven nature makes it less interpretable compared to traditional analysis. An interpretability study reveals the machine's decision-making logic, allowing us to learn from the machine to feed back to the traditional analysis. In this work, we present the first machine learning analysis of the data from the Majorana Demonstrator; this is also the first interpretable machine learning analysis of any germanium detector experiment. Two gradient boosted decision tree models are trained to learn from the data, and a game-theory-based model interpretability study is conducted to understand the origin of the classification power. By learning from data, this analysis recognizes the correlations among reconstruction parameters to further enhance the background rejection performance. By learning from the machine, this analysis reveals the importance of new background categories to reciprocally benefit the standard Majorana analysis. This model is highly compatible with next-generation germanium detector experiments like LEGEND since it can be simultaneously trained on a large number of detectors.

Published
2023

17. Exotic dark matter search with the Majorana Demonstrator

Author

Arnquist, I. J., Avignone III, F. T., Barabash, A. S., Barton, C. J., Bhimani, K. H., Blalock, E., Bos, B., Busch, M., Buuck, M., Caldwell, T. S., Chan, Y-D., Christofferson, C. D., Chu, P. -H., Clark, M. L., Cuesta, C., Detwiler, J. A., Efremenko, Yu., Ejiri, H., Elliott, S. R., Giovanetti, G. K., Green, M. P., Gruszko, J., Guinn, I. S., Guiseppe, V. E., Haufe, C. R., Henning, R., Aguilar, D. Hervas, Hoppe, E. W., Hostiuc, A., Kidd, M. F., Kim, I., Kouzes, R. T., Lannen V, T. E., Li, A., Lopez, A. M., López-Castaño, J. M., Martin, E. L., Martin, R. D., Massarczyk, R., Meijer, S. J., Mertens, S., Oli, T. K., Othman, G., Paudel, L. S., Pettus, W., Poon, A. W. P., Radford, D. C., Reine, A. L., Rielage, K., Ruof, N. W., Schaper, D. C., Tedeschi, D., Varner, R. L., Vasilyev, S., Wilkerson, J. F., Wiseman, C., Xu, W., Yu, C. -H., and Zhu, B. X.

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

With excellent energy resolution and ultra-low level radiogenic backgrounds, the high-purity germanium detectors in the Majorana Demonstrator enable searches for several classes of exotic dark matter (DM) models. In this work, we report new experimental limits on keV-scale sterile neutrino DM via the transition magnetic moment from conversion to active neutrinos, $\nu_s \rightarrow \nu_a$. We report new limits on fermionic dark matter absorption ($\chi + A \rightarrow \nu + A$) and sub-GeV DM-nucleus 3$\rightarrow$2 scattering ($\chi + \chi + A \rightarrow \phi + A$), and new exclusion limits for bosonic dark matter (axionlike particles and dark photons). These searches utilize the (1--100)-keV low energy region of a 37.5-kg y exposure collected by the Demonstrator between May 2016 and November 2019, using a set of $^{76}$Ge-enriched detectors whose surface exposure time was carefully controlled, resulting in extremely low levels of cosmogenic activation., Comment: 7 pages, 6 figures

Published
2022
Full Text
View/download PDF

18. Search for solar axions via axion-photon coupling with the Majorana Demonstrator

Author

Arnquist, I. J., Avignone III, F. T., Barabash, A. S., Barton, C. J., Bhimani, K. H., Blalock, E., Bos, B., Busch, M., Buuck, M., Caldwell, T. S., Chan, Y-D., Christofferson, C. D., Chu, P. -H., Clark, M. L., Cuesta, C., Detwiler, J. A., Efremenko, Yu., Ejiri, H., Elliott, S. R., Giovanetti, G. K., Green, M. P., Gruszko, J., Guinn, I. S., Guiseppe, V. E., Haufe, C. R., Henning, R., Aguilar, D. Hervas, Hoppe, E. W., Hostiuc, A., Kidd, M. F., Kim, I., Kouzes, R. T., Lannen V, T. E., Li, A., Lopez, A. M., López-Castaño, J. M., Martin, E. L., Martin, R. D., Massarczyk, R., Meijer, S. J., Oli, T. K., Othman, G., Paudel, L. S., Pettus, W., Poon, A. W. P., Radford, D. C., Reine, A. L., Rielage, K., Ruof, N. W., Schaper, D. C., Tedeschi, D., Varner, R. L., Vasilyev, S., Wilkerson, J. F., Wiseman, C., Xu, W., Yu, C. -H., and Zhu, B. X.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

Axions were originally proposed to explain the strong-CP problem in QCD. Through the axion-photon coupling, the Sun could be a major source of axions, which could be measured in solid state detection experiments with enhancements due to coherent Primakoff-Bragg scattering. The Majorana Demonstrator experiment has searched for solar axions with a set of $^{76}$Ge-enriched high purity germanium detectors using a 33 kg-yr exposure collected between Jan. 2017 and Nov. 2019. A temporal-energy analysis gives a new limit on the axion-photon coupling as $g_{a\gamma}<1.45\times 10^{-9}$ GeV$^{-1}$ (95% C.I.) for axions with mass up to 100 eV/$c^2$. This improves laboratory-based limits between about 1 eV/$c^2$ and 100 eV/$c^2$., Comment: Minor updates to match published version

Published
2022
Full Text
View/download PDF

19. Experimental study of 13C({\alpha},n)16O reactions in the Majorana Demonstrator calibration data

Author

MAJORANA Collaboration, Arnquist, I. J., Avignone III, F. T., Barabash, A. S., Barton, C. J., Bhimani, K. H., Blalock, E., Bos, B., Busch, M., Buuck, M., Caldwell, T. S., Chan, Y-D., Christofferson, C. D., Chu, P. -H., Clark, M. L., Cuesta, C., Detwiler, J. A., Efremenko, Yu., Ejiri, H., Elliott, S. R., Giovanetti, G. K., Green, M. P., Gruszko, J., Guinn, I. S., Guiseppe, V. E., Haufe, C. R., Henning, R., Aguilar, D. Hervas, Hoppe, E. W., Hostiuc, A., Kidd, M. F., Kim, I., Kouzes, R. T., Lannen V, T. E., Li, A., Lopez, A. M., Lopez-Castano, J. M., Martin, E. L., Martin, R. D., Massarczyk, R., Meijer, S. J., Oli, T. K., Othman, G., Paudel, L. S., Pettus, W., Poon, A. W. P., Radford, D. C., Reine, A. L., Rielage, K., Ruof, N. W., Tedeschi, D., Varner, R. L., Vasilyev, S., Wilkerson, J. F., Wiseman, C., Xu, W., Yu, C. -H., and Zhu, B. X.

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

Neutron captures and delayed decays of reaction products are common sources of backgrounds in ultra-rare event searches. In this work, we studied $^{13}$C($\alpha,n)^{16}$O reactions induced by $\alpha$-particles emitted within the calibration sources of the \textsc{Majorana Demonstrator}. These sources are thorium-based calibration standards enclosed in carbon-rich materials. The reaction rate was estimated by using the 6129-keV $\gamma$-rays emitted from the excited $^{16}$O states that are populated when the incoming $\alpha$-particles exceed the reaction Q-value. Thanks to the excellent energy performance of the \textsc{Demonstrator}'s germanium detectors, these characteristic photons can be clearly observed in the calibration data. Facilitated by \textsc{Geant4} simulations, a comparison between the observed 6129-keV photon rates and predictions by a TALYS-based software was performed. The measurements and predictions were found to be consistent, albeit with large statistical uncertainties. This agreement provides support for background projections from ($\alpha,n$)-reactions in future double-beta decay search efforts., Comment: Published version

Published
2022
Full Text
View/download PDF

20. Search for charge nonconservation and Pauli exclusion principle violation with the Majorana Demonstrator

Author

MAJORANA Collaboration, Arnquist, I. J., Avignone III, F. T., Barabash, A. S., Barton, C. J., Bhimani, K. H., Blalock, E., Bos, B., Busch, M., Buuck, M., Caldwell, T. S., Chan, Y-D., Christofferson, C. D., Chu, P. -H., Clark, M. L., Cuesta, C., Detwiler, J. A., Efremenko, Yu., Ejiri, H., Elliott, S. R., Giovanetti, G. K., Green, M. P., Gruszko, J., Guinn, I. S., Guiseppe, V. E., Haufe, C. R., Henning, R., Aguilar, D. Hervas, Hoppe, E. W., Hostiuc, A., Kidd, M. F., Kim, I., Kouzes, R. T., Lannen V, T. E., Li, A., Lopez, A. M., López-Castaño, J. M., Martin, E. L., Martin, R. D., Massarczyk, R., Meijer, S. J., Oli, T. K., Paudel, L. S., Pettus, W., Poon, A. W. P., Radford, D. C., Reine, A. L., Rielage, K., Ruof, N. W., Schaper, D. C., Tedeschi, D., Varner, R. L., Vasilyev, S., Wilkerson, J. F., Wiseman, C., Xu, W., Yu, C. -H., and Zhu, B. X.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

Charge conservation and the Pauli exclusion principle (PEP) result from fundamental symmetries in the Standard Model, and are typically taken as axiomatic. High-precision tests for small violations of these symmetries could point to new physics. In this work we consider three models for violation of these processes which would produce detectable ionization in the high-purity germanium detectors of the Majorana Demonstrator. Using a 37.5 kg-yr exposure, we report a new lower limit on the electron mean lifetime of $\tau_e > 3.2 \times 10^{25}$ yr (90\% CL), the best result for this decay channel ($e \rightarrow \nu_e \overline{\nu_e} \nu_e$ or more generally $e \rightarrow \mathrm{invisibles}$) in more than two decades. We also present searches for two types of violation of the PEP, setting new limits on the probability of two electrons forming a symmetric quantum state. Using our $^{228}$Th calibration data set, which introduces electrons new to the system through electron-positron pair production, we obtain a world-leading model-independent limit for a terrestrial experiment of $\beta^2/2 < 1.0 \times 10^{-3}$ (99.7\% CL). Our 37.5 kg-yr exposure is also used to search for a process where an electron in an atomic system spontaneously violates the PEP, resulting in a model-dependent upper limit of $\beta^2/2 < 1.0 \times 10^{-48}$ (90\% CL).

Published
2022
Full Text
View/download PDF

21. Search for Spontaneous Radiation from Wavefunction Collapse in the Majorana Demonstrator

Author

Arnquist, I. J., Avignone III, F. T., Barabash, A. S., Barton, C. J., Blalock, E., Bos, B., Busch, M., Buuck, M., Caldwell, T. S., Chan, Y-D., Christofferson, C. D., Chu, P. -H., Clark, M. L., Cuesta, C., Detwiler, J. A., Efremenko, Yu., Ejiri, H., Elliott, S. R., Giovanetti, G. K., Green, M. P., Gruszko, J., Guinn, I. S., Guiseppe, V. E., Haufe, C. R., Henning, R., Aguilar, D. Hervas, Hoppe, E. W., Hostiuc, A., Kim, I., Kouzes, R. T., Lannen V, T. E., Lopez, A. M., López-Castaño, J. M., Martin, E. L., Martin, R. D., Massarczyk, R., Meijer, S. J., Oli, T. K., Othman, G., Paudel, L. S., Pettus, W., Poon, A. W. P., Radford, D. C., Reine, A. L., Rielage, K., Ruof, N. W., Tedeschi, D., Varner, R. L., Vasilyev, S., Wilkerson, J. F., Wiseman, C., Xu, W., Yu, C. -H., and Zhu, B. X.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

The Majorana Demonstrator neutrinoless double-beta decay experiment comprises a 44 kg (30 kg enriched in $^{76}\mathrm{Ge}$) array of $p$-type, point-contact germanium detectors. With its unprecedented energy resolution and ultralow backgrounds, Majorana also searches for rare event signatures from beyond standard model physics in the low energy region below 100 keV. In this Letter, we test the continuous spontaneous localization (CSL) model, one of the mathematically well-motivated wave function collapse models aimed at solving the long-standing unresolved quantum mechanical measurement problem. While the CSL predicts the existence of a detectable radiation signature in the x-ray domain, we find no evidence of such radiation in the 19--100 keV range in a 37.5 kg-y enriched germanium exposure collected between December 31, 2015, and November 27, 2019, with the Demonstrator. We explored both the non-mass-proportional (n-m-p) and the mass-proportional (m-p) versions of the CSL with two different assumptions: that only the quasifree electrons can emit the x-ray radiation and that the nucleus can coherently emit an amplified radiation. In all cases, we set the most stringent upper limit to date for the white CSL model on the collapse rate, $\lambda$, providing a factor of 40--100 improvement in sensitivity over comparable searches. Our limit is the most stringent for large parts of the allowed parameter space. If the result is interpreted in terms of the Di\`osi-Penrose gravitational wave function collapse model, the lower bound with a 95% confidence level is almost an order of magnitude improvement over the previous best limit., Comment: This document was corrected in accordance with the erratum: https://doi.org/10.1103/PhysRevLett.130.239902. The number presented in the recent version of this article is correct

Published
2022
Full Text
View/download PDF

22. Search for Spontaneous Radiation from Wave Function Collapse in the Majorana Demonstrator

Author

Arnquist, IJ, Avignone, FT, Barabash, AS, Barton, CJ, Bhimani, KH, Blalock, E, Bos, B, Busch, M, Buuck, M, Caldwell, TS, Chan, Y-D, Christofferson, CD, Chu, P-H, Clark, ML, Cuesta, C, Detwiler, JA, Efremenko, Yu, Ejiri, H, Elliott, SR, Giovanetti, GK, Green, MP, Gruszko, J, Guinn, IS, Guiseppe, VE, Haufe, CR, Henning, R, Hervas Aguilar, D, Hoppe, EW, Hostiuc, A, Kim, I, Kouzes, RT, Lannen V, TE, Li, A, Lopez, AM, López-Castaño, JM, Martin, EL, Martin, RD, Massarczyk, R, Meijer, SJ, Oli, TK, Othman, G, Paudel, LS, Pettus, W, Poon, AWP, Radford, DC, Reine, AL, Rielage, K, Ruof, NW, Tedeschi, D, Varner, RL, Vasilyev, S, Wilkerson, JF, Wiseman, C, Xu, W, Yu, C-H, and Zhu, BX

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Majorana Collaboration, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract

The Majorana Demonstrator neutrinoless double-beta decay experiment comprises a 44 kg (30 kg enriched in ^{76}Ge) array of p-type, point-contact germanium detectors. With its unprecedented energy resolution and ultralow backgrounds, Majorana also searches for rare event signatures from beyond standard model physics in the low energy region below 100 keV. In this Letter, we test the continuous spontaneous localization (CSL) model, one of the mathematically well-motivated wave function collapse models aimed at solving the long-standing unresolved quantum mechanical measurement problem. While the CSL predicts the existence of a detectable radiation signature in the x-ray domain, we find no evidence of such radiation in the 19-100 keV range in a 37.5 kg-y enriched germanium exposure collected between December 31, 2015, and November 27, 2019, with the Demonstrator. We explored both the non-mass-proportional (n-m-p) and the mass-proportional (m-p) versions of the CSL with two different assumptions: that only the quasifree electrons can emit the x-ray radiation and that the nucleus can coherently emit an amplified radiation. In all cases, we set the most stringent upper limit to date for the white CSL model on the collapse rate, λ, providing a factor of 40-100 improvement in sensitivity over comparable searches. Our limit is the most stringent for large parts of the allowed parameter space. If the result is interpreted in terms of the Diòsi-Penrose gravitational wave function collapse model, the lower bound with a 95% confidence level is almost an order of magnitude improvement over the previous best limit.

Published
2022

23. Search for Solar Axions via Axion-Photon Coupling with the Majorana Demonstrator

Author

Arnquist, IJ, Avignone, FT, Barabash, AS, Barton, CJ, Bhimani, KH, Blalock, E, Bos, B, Busch, M, Buuck, M, Caldwell, TS, Chan, Y-D, Christofferson, CD, Chu, P-H, Clark, ML, Cuesta, C, Detwiler, JA, Efremenko, Yu, Ejiri, H, Elliott, SR, Giovanetti, GK, Green, MP, Gruszko, J, Guinn, IS, Guiseppe, VE, Haufe, CR, Henning, R, Hervas Aguilar, D, Hoppe, EW, Hostiuc, A, Kidd, MF, Kim, I, Kouzes, RT, Lannen V, TE, Li, A, Lopez, AM, López-Castaño, JM, Martin, EL, Martin, RD, Massarczyk, R, Meijer, SJ, Oli, TK, Othman, G, Paudel, LS, Pettus, W, Poon, AWP, Radford, DC, Reine, AL, Rielage, K, Ruof, NW, Schaper, DC, Tedeschi, D, Varner, RL, Vasilyev, S, Wilkerson, JF, Wiseman, C, Xu, W, Yu, C-H, and Zhu, BX

Subjects
Particle and High Energy Physics, Physical Sciences, Majorana Collaboration, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract

Axions were originally proposed to explain the strong-CP problem in QCD. Through axion-photon coupling, the Sun could be a major source of axions, which could be measured in solid state detection experiments with enhancements due to coherent Primakoff-Bragg scattering. The Majorana Demonstrator experiment has searched for solar axions with a set of ^{76}Ge-enriched high purity germanium detectors using a 33 kg-yr exposure collected between January, 2017 and November, 2019. A temporal-energy analysis gives a new limit on the axion-photon coupling as g_{aγ}

Published
2022

24. The MAJORANA DEMONSTRATOR Readout Electronics System

Author

Abgrall, N., Amman, M., Arnquist, I. J., Avignone III, F. T., Barabash, A. S., Barton, C. J., Barton, P. J., Bertrand, F. E., Bhimani, K. H., Bos, B., Bradley, A. W., Burritt, T. H., Busch, M., Buuck, M., Caldwell, T. S., Chan, Y-D., Christofferson, C. D., Chu, P. -H., Clark, M. L., Cooper, R. J., Cuesta, C., Detwiler, J. A., Drobizhev, A., Edwins, D. W., Efremenko, Yu., Ejiri, H., Elliott, S. R., Gilliss, T., Giovanetti, G. K., Green, M. P., Gruszko, J., Guinn, I. S., Guiseppe, V. E., Haufe, C. R., Hegedus, R. J., Henning, R., Aguilar, D. Hervas, Hoppe, E. W., Hostiuc, A., Kidd, M. F., Kim, I., Kouzes, R. T., Li, A., Loach, J. C., Lopez, A. M., López-Castaño, J. M., Luke, P. N., Martin, E. L., Martin, R. D., Massarczyk, R., Meijer, S. J., Mertens, S., Myslik, J., Oli, T. K., Othman, G., Peterson, D., Pettus, W., Poon, A. W. P., Radford, D. C., Rager, J., Reine, A. L., Rielage, K., Robertson, R. G. H., Ruof, N. W., Sayki, B., Stortini, M. J., Tedeschi, D., Turqueti, M., Van Wechel, T. D., Varner, R. L., Vasilyev, S., Vetter, K., Wilkerson, J. F., Wiseman, C., Xu, W., Yaver, H., Yu, C. -H., Zhu, B. X., and Zimmermann, S.

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

The MAJORANA DEMONSTRATOR comprises two arrays of high-purity germanium detectors constructed to search for neutrinoless double-beta decay in 76-Ge and other physics beyond the Standard Model. Its readout electronics were designed to have low electronic noise, and radioactive backgrounds were minimized by using low-mass components and low-radioactivity materials near the detectors. This paper provides a description of all components of the MAJORANA DEMONSTRATOR readout electronics, spanning the front-end electronics and internal cabling, back-end electronics, digitizer, and power supplies, along with the grounding scheme. The spectroscopic performance achieved with these readout electronics is also demonstrated., Comment: For submission to JINST, 17 figures. v2: revised version

Published
2021
Full Text
View/download PDF

25. Signatures of muonic activation in the Majorana Demonstrator

Author

Arnquist, I. J., Avignone III, F. T., Barabash, A. S., Barton, C. J., Bertrand, F. E., Blalock, E., Bos, B., Busch, M., Buuck, M., Caldwell, T. S., Chan, Y-D., Christofferson, C. D., Chu, P. -H., Clark, M. L., Cuesta, C., Detwiler, J. A., Edwards, T. R., Efremenko, Yu., Ejiri, H., Elliott, S. R., Giovanetti, G. K., Green, M. P., Gruszko, J., Guinn, I. S., Guiseppe, V. E., Haufe, C. R., Henning, R., Aguilar, D. Hervas, Hoppe, E. W., Hostiuc, A., Kidd, M. F., Kim, I., Kouzes, R. T., Lannen V, T. E., Lopez, A. M., López-Castaño, J. M., Martin, E. L., Martin, R. D., Massarczyk, R., Meijer, S. J., Mertens, S., Oli, T. K., Othman, G., Paudel, L. S., Pettus, W., Poon, A. W. P., Radford, D. C., Reine, A. L., Rielage, K., Ruof, N. W., Tedeschi, D., Varner, R. L., Vasilyev, S., Wilkerson, J. F., Wiseman, C., Xu, W., Yu, C. -H., and Zhu, B. X.

Subjects
Nuclear Experiment, Physics - Instrumentation and Detectors
Abstract

Experiments searching for very rare processes such as neutrinoless double-beta decay require a detailed understanding of all sources of background. Signals from radioactive impurities present in construction and detector materials can be suppressed using a number of well-understood techniques. Background from in-situ cosmogenic interactions can be reduced by siting an experiment deep underground. However, the next generation of such experiments have unprecedented sensitivity goals of 10$^{28}$ years half-life with background rates of 10$^{-5}$cts/(keV kg yr) in the region of interest. To achieve these goals, the remaining cosmogenic background must be well understood. In the work presented here, Majorana Demonstrator data is used to search for decay signatures of meta-stable germanium isotopes. Contributions to the region of interest in energy and time are estimated using simulations, and compared to Demonstrator data. Correlated time-delayed signals are used to identify decay signatures of isotopes produced in the germanium detectors. A good agreement between expected and measured rate is found and different simulation frameworks are used to estimate the uncertainties of the predictions. The simulation campaign is then extended to characterize the background for the LEGEND experiment, a proposed tonne-scale effort searching for neutrinoless double-beta decay in $^{76}$Ge., Comment: 14 pages, 12 figures

Published
2021
Full Text
View/download PDF

26. Experimental study of C13(α,n)O16 reactions in the Majorana Demonstrator calibration data

Author

Arnquist, IJ, Avignone, FT, Barabash, AS, Barton, CJ, Bhimani, KH, Blalock, E, Bos, B, Busch, M, Buuck, M, Caldwell, TS, Chan, Y-D, Christofferson, CD, Chu, P-H, Clark, ML, Cuesta, C, Detwiler, JA, Efremenko, Yu, Ejiri, H, Elliott, SR, Giovanetti, GK, Green, MP, Gruszko, J, Guinn, IS, Guiseppe, VE, Haufe, CR, Henning, R, Aguilar, D Hervas, Hoppe, EW, Hostiuc, A, Kidd, MF, Kim, I, Kouzes, RT, Lannen, TE, Li, A, Lopez, AM, López-Castaño, JM, Martin, EL, Martin, RD, Massarczyk, R, Meijer, SJ, Oli, TK, Othman, G, Paudel, LS, Pettus, W, Poon, AWP, Radford, DC, Reine, AL, Rielage, K, Ruof, NW, Tedeschi, D, Varner, RL, Vasilyev, S, Wilkerson, JF, Wiseman, C, Xu, W, Yu, C-H, and Zhu, BX

Subjects
Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, Nuclear and plasma physics
Abstract

Neutron captures and delayed decays of reaction products are common sources of backgrounds in ultrarare event searches. In this work, we studied C13(α,n)O16 reactions induced by α particles emitted within the calibration sources of the Majorana Demonstrator. These sources are thorium-based calibration standards enclosed in carbon-rich materials. The reaction rate was estimated by using the 6129-keV γ rays emitted from the excited O16 states that are populated when the incoming α particles exceed the reaction Q value. Thanks to the excellent energy performance of the Demonstrator's germanium detectors, these characteristic photons can be clearly observed in the calibration data. Facilitated by Geant4 simulations, a comparison between the observed 6129-keV photon rates and predictions by a talys-based software was performed. The measurements and predictions were found to be consistent, albeit with large statistical uncertainties. This agreement provides support for background projections from (α,n) reactions in future double-beta decay search efforts.

Published
2022

27. The Majorana Demonstrator readout electronics system

Author

Abgrall, N, Amman, M, Arnquist, IJ, Avignone, FT, Barabash, AS, Barton, CJ, Barton, PJ, Bertrand, FE, Bhimani, KH, Bos, B, Bradley, AW, Burritt, TH, Busch, M, Buuck, M, Caldwell, TS, Chan, Y-D, Christofferson, CD, Chu, P-H, Clark, ML, Cooper, RJ, Cuesta, C, Detwiler, JA, Drobizhev, A, Edwins, DW, Efremenko, Yu, Ejiri, H, Elliott, SR, Gilliss, T, Giovanetti, GK, Green, MP, Gruszko, J, Guinn, IS, Guiseppe, VE, Haufe, CR, Hegedus, RJ, Henning, R, Aguilar, D Hervas, Hoppe, EW, Hostiuc, A, Kidd, MF, Kim, I, Kouzes, RT, Li, A, Loach, JC, Lopez, AM, López-Castaño, JM, Luke, PN, Martin, EL, Martin, RD, Massarczyk, R, Meijer, SJ, Mertens, S, Myslik, J, Oli, TK, Othman, G, Peterson, D, Pettus, W, Poon, AWP, Radford, DC, Rager, J, Reine, AL, Rielage, K, Robertson, RGH, Ruof, NW, Sayki, B, Stortini, MJ, Tedeschi, D, Turqueti, M, Van Wechel, TD, Varner, RL, Vasilyev, S, Vetter, K, Wilkerson, JF, Wiseman, C, Xu, W, Yaver, H, Yu, C-H, Zhu, BX, and Zimmermann, S

Subjects
Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, Double-beta decay detectors, Electronic detector readout concepts, Front-end electronics for detector readout, Engineering, Nuclear & Particles Physics, Physical sciences
Abstract

The Majorana Demonstrator comprises two arrays of high-purity germanium detectors constructed to search for neutrinoless double-beta decay in 76Ge and other physics beyond the Standard Model. Its readout electronics were designed to have low electronic noise, and radioactive backgrounds were minimized by using low-mass components and low-radioactivity materials near the detectors. This paper provides a description of all components of the Majorana Demonstrator readout electronics, spanning the front-end electronics and internal cabling, back-end electronics, digitizer, and power supplies, along with the grounding scheme. The spectroscopic performance achieved with these readout electronics is also demonstrated.

Published
2022

28. LEGEND-1000 Preconceptual Design Report

Author

LEGEND Collaboration, Abgrall, N., Abt, I., Agostini, M., Alexander, A., Andreoiu, C., Araujo, G. R., Avignone III, 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., Hakenmüeller, 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., Kermaïdic, Y., Khushbakht, H., Kidd, M., Kihm, T., Kilgus, K., Kim, I., Klimenko, A., Knöpfle, K. T., Kochetov, O., Konovalov, S. I., Kontul, I., Kool, K., Kormos, L. L., Kornoukhov, V. N., Korosec, M., Krause, P., Kuzminov, V. V., López-Castaño, J. M., Lang, K., Laubenstein, M., León, E., Lehnert, B., Leonhardt, A., Li, A., Lindner, M., Lippi, I., Liu, X., Liu, J., Loomba, D., Lubashevskiy, A., Lubsandorzhiev, B., Lusardi, N., Müller, 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., Palušova, 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., Schönert, S., Schültz, A., Schütt, M., Schaper, D. C., Schreiner, J., Schulz, O., Schuster, M., Schwarz, M., Schwingenheuer, B., Selivanenko, O., Shafiee, 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, 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

29. α-event characterization and rejection in point-contact HPGe detectors

Author

Arnquist, IJ, Avignone, FT, Barabash, AS, Barton, CJ, Bertrand, FE, Blalock, E, Bos, B, Busch, M, Buuck, M, Caldwell, TS, Chan, Y-D, Christofferson, CD, Chu, P-H, Clark, ML, Cuesta, C, Detwiler, JA, Drobizhev, A, Edwards, TR, Edwins, DW, Edzards, F, Efremenko, Y, Elliott, SR, Gilliss, T, Giovanetti, GK, Green, MP, Gruszko, J, Guinn, IS, Guiseppe, VE, Haufe, CR, Hegedus, RJ, Henning, R, Aguilar, D Hervas, Hoppe, EW, Hostiuc, A, Kim, I, Kouzes, RT, Lopez, AM, López-Castaño, JM, Martin, EL, Martin, RD, Massarczyk, R, Meijer, SJ, Mertens, S, Myslik, J, Oli, TK, Othman, G, Pettus, W, Poon, AWP, Radford, DC, Rager, J, Reine, AL, Rielage, K, Ruof, NW, Saykı, B, Schönert, S, Stortini, MJ, Tedeschi, D, Varner, RL, Vasilyev, S, Wilkerson, JF, Willers, M, Wiseman, C, Xu, W, Yu, C-H, and Zhu, BX

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, Clinical Research, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Astronomical sciences, Atomic, molecular and optical physics, Particle and high energy physics
Abstract

P-type point contact (PPC) HPGe detectors are a leading technology for rare event searches due to their excellent energy resolution, low thresholds, and multi-site event rejection capabilities. We have characterized a PPC detector's response to α particles incident on the sensitive passivated and p + surfaces, a previously poorly-understood source of background. The detector studied is identical to those in the Majorana Demonstrator experiment, a search for neutrinoless double-beta decay ( 0νββ ) in 76 Ge. α decays on most of the passivated surface exhibit significant energy loss due to charge trapping, with waveforms exhibiting a delayed charge recovery (DCR) signature caused by the slow collection of a fraction of the trapped charge. The DCR is found to be complementary to existing methods of α identification, reliably identifying α background events on the passivated surface of the detector. We demonstrate effective rejection of all surface α events (to within statistical uncertainty) with a loss of only 0.2% of bulk events by combining the DCR discriminator with previously-used methods. The DCR discriminator has been used to reduce the background rate in the 0νββ region of interest window by an order of magnitude in the Majorana Demonstrator  and will be used in the upcoming LEGEND-200 experiment.

Published
2022

30. Signatures of muonic activation in the Majorana Demonstrator

Author

Arnquist, IJ, Avignone, FT, Barabash, AS, Barton, CJ, Bertrand, FE, Blalock, E, Bos, B, Busch, M, Buuck, M, Caldwell, TS, Chan, Y-D, Christofferson, CD, Chu, P-H, Clark, ML, Cuesta, C, Detwiler, JA, Edwards, TR, Efremenko, Yu, Ejiri, H, Elliott, SR, Giovanetti, GK, Green, MP, Gruszko, J, Guinn, IS, Guiseppe, VE, Haufe, CR, Henning, R, Aguilar, D Hervas, Hoppe, EW, Hostiuc, A, Kidd, MF, Kim, I, Kouzes, RT, Lannen, TEV, Lopez, AM, López-Castaño, JM, Martin, EL, Martin, RD, Massarczyk, R, Meijer, SJ, Mertens, S, Oli, TK, Othman, G, Paudel, LS, Pettus, W, Poon, AWP, Radford, DC, Reine, AL, Rielage, K, Ruof, NW, Tedeschi, D, Varner, RL, Vasilyev, S, Wilkerson, JF, Wiseman, C, Xu, W, Yu, C-H, and Zhu, BX

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, Nuclear and plasma physics
Abstract

Experiments searching for very rare processes such as neutrinoless double-beta decay require a detailed understanding of all sources of background. Signals from radioactive impurities present in construction and detector materials can be suppressed using a number of well-understood techniques. Background from in situ cosmogenic interactions can be reduced by siting an experiment deep underground. However, the next generation of such experiments have unprecedented sensitivity goals of 1028 years half-life with background rates of 10-5cts/(keV kg yr) in the region of interest. To achieve these goals, the remaining cosmogenic background must be well understood. In the work presented here, Majorana Demonstrator data are used to search for decay signatures of metastable germanium isotopes. Contributions to the region of interest in energy and time are estimated using simulations and compared to Demonstrator data. Correlated time-delayed signals are used to identify decay signatures of isotopes produced in the germanium detectors. A good agreement between expected and measured rate is found and different simulation frameworks are used to estimate the uncertainties of the predictions. The simulation campaign is then extended to characterize the background for the LEGEND experiment, a proposed tonne-scale effort searching for neutrinoless double-beta decay in Ge76.

Published
2022

31. The Majorana Demonstrator's Search for Double-Beta Decay of $^{76}$Ge to Excited States of $^{76}$Se

Author

Arnquist, I. J., Avignone III, F. T., Barabash, A. S., Barton, C. J., Bertrand, F. E., Blalock, E., Bos, B., Busch, M., Buuck, M., Caldwell, T. S., Chan, Y-D., Christofferson, C. D., Chu, P. -H., Clark, M. L., Cuesta, C., Detwiler, J. A., Drobizhev, A., Edwards, T. R., Edwins, D. W., Efremenko, Yu., Ejiri, H., Elliott, S. R., Gilliss, T., Giovanetti, G. K., Green, M. P., Gruszko, J., Guinn, I. S., Guiseppe, V. E., Haufe, C. R., Henning, R., Aguilar, D. Hervas, Hoppe, E. W., Hostiuc, A., Kidd, M. F., Kim, I., Kouzes, R. T., Lopez, A. M., López-Castaño, J. M., Martin, E. L., Martin, R. D., Massarczyk, R., Meijer, S. J., Mertens, S., Myslik, J., Oli, T. K., Othman, G., Paudel, L. S., Pettus, W., Poon, A. W. P., Radford, D. C., Reine, A. L., Rielage, K., Ruof, N. W., Saykı, B., Stortini, M. J., Tedeschi, D., Varner, R. L., Vasilyev, S., Wilkerson, J. F., Wiseman, C., Xu, W., Yu, C. -H., and Zhu, B. X.

Subjects
Nuclear Experiment
Abstract

The Majorana Demonstrator is a neutrinoless double-beta decay search consisting of a low-background modular array of high-purity germanium detectors, $\sim2/3$ of which are enriched to 88\% in $^{76}$Ge. The experiment is also searching for double-beta decay of $^{76}$Ge to excited states (e.s.) in $^{76}$Se. $^{76}$Ge can decay into three daughter states of $^{76}$Se, with clear event signatures consisting of a $\beta\beta$-decay followed by the prompt emission of one or two $\gamma$-rays. This results with high probability in multi-detector coincidences. The granularity of the Demonstrator detector array enables powerful discrimination of this event signature from backgrounds. Using 41.9~kg-y of isotopic exposure, the Demonstrator has set world leading limits for each e.s.\ decay of $^{76}$Ge, with 90\% CL lower half-life limits in the range of $(0.75-4.0)\times10^{24}$~y. In particular, for the $2\nu$ transition to the first $0^+$ e.s.\ of $^{76}$Se, a lower half-life limit of $7.5\times10^{23}$~y at 90\% CL was achieved., Comment: 16 pages, 11 figures

Published
2020
Full Text
View/download PDF

32. Search for $hep$ solar neutrinos and the diffuse supernova neutrino background using all three phases of the Sudbury Neutrino Observatory

Author

Aharmim, B., Ahmed, S. N., Anthony, A. E., Barros, N., Beier, E. W., Bellerive, A., Beltran, B., Bergevin, M., Biller, S. D., Blucher, E., Bonventre, R., Boudjemline, K., Boulay, M. G., Cai, B., Callaghan, E. J., Caravaca, J., Chan, Y. D., Chauhan, D., Chen, M., Cleveland, B. T., Cox, G. A., Dai, X., Deng, H., Descamps, F. B., Detwiler, J. A., Doe, P. J., Doucas, G., Drouin, P. -L., Dunford, M., Elliott, S. R., Evans, H. C., Ewan, G. T., Farine, J., Fergani, H., Fleurot, F., Ford, R. J., Formaggio, J. A., Gagnon, N., Gilje, K., Goon, J. TM., Graham, K., Guillian, E., Habib, S., Hahn, R. L., Hallin, A. L., Hallman, E. D., Harvey, P. J., Hazama, R., Heintzelman, W. J., Heise, J., Helmer, R. L., Hime, A., Howard, C., Huang, M., Jagam, P., Jamieson, B., Jelley, N. A., Jerkins, M., Keeter, K. J., Klein, J. R., Kormos, L. L., Kos, M., Kraus, C., Krauss, C. B., Krüger, A., Kutter, T., Kyba, C. C. M., Labe, K., Land, B. J., Lange, R., LaTorre, A., Law, J., Lawson, I. T., Lesko, K. T., Leslie, J. R., Levine, I., Loach, J. C., MacLellan, R., Majerus, S., Mak, H. B., Maneira, J., Martin, R. D., Mastbaum, A., McCauley, N., McDonald, A. B., McGee, S. R., Miller, M. L., Monreal, B., Monroe, J., Nickel, B. G., Noble, A. J., O'Keeffe, H. M., Oblath, N. S., Okada, C. E., Ollerhead, R. W., Gann, G. D. Orebi, Oser, S. M., Ott, R. A., Peeters, S. J. M., Poon, A. W. P., Prior, G., Reitzner, S. D., Rielage, K., Robertson, B. C., Robertson, R. G. H., Schwendener, M. H., Secrest, J. A., Seibert, S. R., Simard, O., Sinclair, D., Skensved, P., Sonley, T. J., Stonehill, L. C., Tešić, G., Tolich, N., Tsui, T., Van Berg, R., VanDevender, B. A., Virtue, C. J., Wall, B. L., Waller, D., Tseung, H. Wan Chan, Wark, D. L., Wendland, J., West, N., Wilkerson, J. F., Wilson, J. R., Winchester, T., Wright, A., Yeh, M., Zhang, F., and Zuber, K.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

A search has been performed for neutrinos from two sources, the $hep$ reaction in the solar $pp$ fusion chain and the $\nu_e$ component of the diffuse supernova neutrino background (DSNB), using the full dataset of the Sudbury Neutrino Observatory with a total exposure of 2.47 kton-years after fiducialization. The $hep$ search is performed using both a single-bin counting analysis and a likelihood fit. We find a best-fit flux that is compatible with solar model predictions while remaining consistent with zero flux, and set a one-sided upper limit of $\Phi_{hep} < 30\times10^{3}~\mathrm{cm}^{-2}~\mathrm{s}^{-1}$ [90% credible interval (CI)]. No events are observed in the DSNB search region, and we set an improved upper bound on the $\nu_e$ component of the DSNB flux of $\Phi^\mathrm{DSNB}_{\nu_e} < 19~\textrm{cm}^{-2}~\textrm{s}^{-1}$ (90% CI) in the energy range $22.9 < E_\nu < 36.9$~MeV., Comment: 11 pages, 6 figures

Published
2020
Full Text
View/download PDF

33. $\alpha$-event Characterization and Rejection in Point-Contact HPGe Detectors

Author

The MAJORANA Collaboration, Arnquist, I. J., Avignone III, F. T., Barabash, A. S., Barton, C. J., Bertrand, F. E., Blalock, E., Bos, B., Busch, M., Buuck, M., Caldwell, T. S., Chan, Y-D., Christofferson, C. D., Chu, P. -H., Clark, M. L., Cuesta, C., Detwiler, J. A., Drobizhev, A., Edwards, T. R., Edwins, D. W., Efremenko, Yu., Elliott, S. R., Gilliss, T., Giovanetti, G. K., Green, M. P., Gruszko, J., Guinn, I. S., Guiseppe, V. E., Haufe, C. R., Hegedus, R. J., Henning, R., Aguilar, D. Hervas, Hoppe, E. W., Hostiuc, A., Kim, I., Kouzes, R. T., Lopez, A. M., López-Castaño, J. M., Martin, E. L., Martin, R. D., Massarczyk, R., Meijer, S. J., Mertens, S., Myslik, J., Oli, T. K., Othman, G., Pettus, W., Poon, A. W. P., Radford, D. C., Rager, J., Reine, A. L., Rielage, K., Ruof, N. W., Saykı, B., Schönert, S., Stortini, M. J., Tedeschi, D., Varner, R. L., Vasilyev, S., Wilkerson, J. F., Willers, M., Wiseman, C., Xu, W., Yu, C. -H., and Zhu, B. X.

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

P-type point contact (PPC) HPGe detectors are a leading technology for rare event searches due to their excellent energy resolution, low thresholds, and multi-site event rejection capabilities. We have characterized a PPC detector's response to $\alpha$ particles incident on the sensitive passivated and p+ surfaces, a previously poorly-understood source of background. The detector studied is identical to those in the MAJORANA DEMONSTRATOR experiment, a search for neutrinoless double-beta decay ($0\nu\beta\beta$) in $^{76}$Ge. $\alpha$ decays on most of the passivated surface exhibit significant energy loss due to charge trapping, with waveforms exhibiting a delayed charge recovery (DCR) signature caused by the slow collection of a fraction of the trapped charge. The DCR is found to be complementary to existing methods of $\alpha$ identification, reliably identifying $\alpha$ background events on the passivated surface of the detector. We demonstrate effective rejection of all surface $\alpha$ events (to within statistical uncertainty) with a loss of only 0.2% of bulk events by combining the DCR discriminator with previously-used methods. The DCR discriminator has been used to reduce the background rate in the $0\nu\beta\beta$ region of interest window by an order of magnitude in the MAJORANA DEMONSTRATOR, and will be used in the upcoming LEGEND-200 experiment., Comment: Accepted for publication in European Journal of Physics C

Published
2020
Full Text
View/download PDF

34. ADC Nonlinearity Correction for the MAJORANA DEMONSTRATOR

Author

Abgrall, N., Allmond, J. M., Arnquist, I. J., Avignone III, F. T., Barabash, A. S., Barton, C. J., Bertrand, F. E., Bos, B., Busch, M., Buuck, M., Caldwell, T. S., Campbell, C. M., Chan, Y-D., Christofferson, C. D., Chu, P. -H., Clark, M. L., Crawford, H. L., Cuesta, C., Detwiler, J. A., Drobizhev, A., Edwins, D. W., Efremenko, Yu., Ejiri, H., Elliott, S. R., Gilliss, T., Giovanetti, G. K., Green, M. P., Gruszko, J., Guinn, I. S., Guiseppe, V. E., Haufe, C. R., Hegedus, R. J., Henning, R., Aguilar, D. Hervas, Hoppe, E. W., Hostiuc, A., Kidd, M. F., Kim, I., Kouzes, R. T., Lopez, A. M., Lopez-Castano, J. M., Martin, E. L., Martin, R. D., Massarczyk, R., Meijer, S. J., Mertens, S., Myslik, J., Oli, T. K., Othman, G., Pettus, W., Poon, A. W. P., Radford, D. C., Rager, J., Reine, A. L., Rielage, K., Ruof, N. W., Stortini, M. J., Tedeschi, D., Varner, R. L., Vasilyev, S., White, B. R., Wilkerson, J. F., Wiseman, C., Xu, W., Yu, C. -H., Zhu, B. X., and Shanks, B.

Subjects
Physics - Instrumentation and Detectors, Nuclear Experiment
Abstract

Imperfections in analog-to-digital conversion (ADC) cannot be ignored when signal digitization requirements demand both wide dynamic range and high resolution, as is the case for the Majorana Demonstrator 76Ge neutrinoless double beta decay search. Enabling the experiment's high-resolution spectral analysis and efficient pulse shape discrimination required careful measurement and correction of ADC nonlinearites. A simple measurement protocol was developed that did not require sophisticated equipment or lengthy data taking campaigns. A slope-dependent hysteresis was observed and characterized. A correction applied to digitized waveforms prior to signal processing reduced the differential and integral nonlinearites by an order of magnitude, eliminating these as dominant contributions to the systematic energy uncertainty at the double-beta decay Q value.

Published
2020
Full Text
View/download PDF

35. ADC Nonlinearity Correction for the Majorana Demonstrator

Author

Abgrall, N, Allmond, JM, Arnquist, IJ, Avignone, FT, Barabash, AS, Barton, CJ, Bertrand, FE, Bos, B, Busch, M, Buuck, M, Caldwell, TS, Campbell, CM, Chan, Y-D, Christofferson, CD, Chu, Pinghan, Clark, ML, Crawford, HL, Cuesta, C, Detwiler, JA, Drobizhev, A, Edwins, DW, Efremenko, Yu, Ejiri, H, Elliott, SR, Gilliss, T, Giovanetti, GK, Green, MP, Gruszko, J, Guinn, IS, Guiseppe, VE, Haufe, CR, Hegedus, RJ, Henning, R, Aguilar, D Hervas, Hoppe, EW, Hostiuc, A, Kidd, MF, Kim, I, Kouzes, RT, Lopez, AM, Lopez-Castano, JM, Martin, EL, Martin, RD, Massarczyk, R, Meijer, SJ, Mertens, S, Myslik, J, Oli, TK, Othman, G, Pettus, W, Poon, AWP, Radford, DC, Rager, J, Reine, AL, Rielage, K, Ruof, NW, Stortini, MJ, Tedeschi, D, Varner, RL, Vasilyev, S, White, BR, Wilkerson, JF, Wiseman, C, Xu, W, Yu, C-H, Zhu, BX, and Shanks, B

Subjects
Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, Gamma-ray detectors, neutrinoless double-beta decay, physics.ins-det, nucl-ex, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Other Physical Sciences, Biomedical Engineering, Nuclear & Particles Physics, Nuclear and plasma physics
Abstract

Imperfections in analog-to-digital conversion (ADC) cannot be ignored when signal digitization requirements demand both wide dynamic range and high resolution, as is the case for the Majorana Demonstrator 76Ge neutrinoless double-beta decay search. Enabling the experiment's high-resolution spectral analysis and efficient pulse shape discrimination required careful measurement and correction of ADC nonlinearities. A simple measurement protocol was developed that did not require sophisticated equipment or lengthy data-taking campaigns. A slope-dependent hysteresis was observed and characterized. A correction applied to digitized waveforms prior to signal processing reduced the differential and integral nonlinearities by an order of magnitude, eliminating these as dominant contributions to the systematic energy uncertainty at the double-beta decay Q value.

Published
2021

36. Search for double-β decay of Ge76 to excited states of Se76 with the majorana demonstrator

Author

Arnquist, IJ, Avignone, FT, Barabash, AS, Barton, CJ, Bertrand, FE, Blalock, E, Bos, B, Busch, M, Buuck, M, Caldwell, TS, Chan, Y-D, Christofferson, CD, Chu, P-H, Clark, ML, Cuesta, C, Detwiler, JA, Drobizhev, A, Edwards, TR, Edwins, DW, Efremenko, Yu, Ejiri, H, Elliott, SR, Gilliss, T, Giovanetti, GK, Green, MP, Gruszko, J, Guinn, IS, Guiseppe, VE, Haufe, CR, Henning, R, Aguilar, D Hervas, Hoppe, EW, Hostiuc, A, Kidd, MF, Kim, I, Kouzes, RT, Lopez, AM, López-Castaño, JM, Martin, EL, Martin, RD, Massarczyk, R, Meijer, SJ, Mertens, S, Myslik, J, Oli, TK, Othman, G, Paudel, LS, Pettus, W, Poon, AWP, Radford, DC, Reine, AL, Rielage, K, Ruof, NW, Saykı, B, Stortini, MJ, Tedeschi, D, Varner, RL, Vasilyev, S, Wilkerson, JF, Wiseman, C, Xu, W, Yu, C-H, and Zhu, BX

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, Nuclear and plasma physics
Abstract

The majorana demonstrator is a neutrinoless double-β decay search consisting of a low-background modular array of high-purity germanium detectors, ∼2/3 of which are enriched to 88% in Ge76. The experiment is also searching for double-beta decay of Ge76 to excited states (e.s.) in Se76. Ge76 can decay into three daughter states of Se76, with clear event signatures consisting of a ββ-decay followed by the prompt emission of one or two γ rays. This results with high probability in multi-detector coincidences. The granularity of the demonstrator detector array enables powerful discrimination of this event signature from backgrounds. Using 41.9 kg yr of isotopic exposure, the demonstrator has set world leading limits for each e.s. decay of Ge76, with 90% CL lower half-life limits in the range of (0.75-4.0)×1024 yr. In particular, for the 2ν transition to the first 0+ e.s. of Se76, a lower half-life limit of 7.5×1023 yr at 90% CL was achieved.

Published
2021

37. A Low Energy Rare Event Search with the Majorana Demonstrator

Author

MAJORANA Collaboration, Wiseman, C., Arnquist, I. J., Avignone III, F. T., Barabash, A. S., Barton, C. J., Bertrand, F. E., Bos, B., Busch, M., Buuck, M., Caldwell, T. S., Chan, Y-D., Christofferson, C. D., Chu, P. -H., Clark, M. L., Cuesta, C., Detwiler, J. A., Drobizhev, A., Edwins, D. W., Efremenko, Yu., Ejiri, H., Elliott, S. R., Gilliss, T., Giovanetti, G. K., Green, M. P., Gruszko, J., Guinn, I. S., Guiseppe, V. E., Haufe, C. R., Hegedus, R. J., Henning, R., Aguilar, D. Hervas, Hoppe, E. W., Hostiuc, A., Kidd, M. F., Kim, I., Kouzes, R. T., Lopez, A. M., Lopez-Castano, J. M., Martin, E. L., Martin, R. D., Massarczyk, R., Meijer, S. J., Mertens, S., Myslik, J., Oli, T. K., Othman, G., Pettus, W., Poon, A. W. P., Radford, D. C., Rager, J., Reine, A. L., Rielage, K., Ruof, N. W., Sayki, B., Stortini, M. J., Tedeschi, D., Varner, R. L., Wilkerson, J. F., Xu, W., Yu, C. -H., and Zhu, B. X.

Subjects
Nuclear Experiment, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The MAJORANA DEMONSTRATOR is sensitive to rare events near its energy threshold, including bosonic dark matter, solar axions, and lightly ionizing particles. In this analysis, a novel training set of low energy small-angle Compton scatter events is used to determine the efficiency of pulse shape analysis cuts, and we present updated bosonic dark matter and solar axion results from an 11.17 kg-y dataset using a 5 keV analysis threshold., Comment: 4 pages, 4 figures. Proceedings of the 16th International Conference on Topics in Astroparticle and Underground Physics (TAUP 2019), September 9-13, 2019, Toyama, Japan

Published
2019
Full Text
View/download PDF

38. Results of the MAJORANA DEMONSTRATOR's Search for Double-Beta Decay of $^{76}$Ge to Excited States of $^{76}$Se

Author

Guinn, I. S., Arnquist, I. J., Avignone III, F. T., Barabash, A. S., Barton, C. J., Bertrand, F. E., Bos, B., Busch, M., Buuck, M., Caldwell, T. S., Chan, Y-D., Christofferson, C. D., Chu, P-H., Clark, M. L., Cuesta, C., Detwiler, J. A., Drobizhev, A., Edwins, D. W., Efremenko, Yu., Ejiri, H., Elliott, S. R., Gilliss, T., Giovanetti, G. K., Green, M. P., Gruszko, J., Guiseppe, V. E., Haufe, C. R., Hegedus, R. J., Henning, R., Aguilar, D. Hervas, Hoppe, E. W., Hostiuc, A., Kidd, M. F., Kim, I., Kouzes, R. T., Lopez, A. M., no, J. M. López-Casta, Martin, E. L., Martin, R. D., Massarczyk, R., Meijer, S. J., Mertens, S., Myslik, J., Oli, T. K., Othman, G., Pettus, W., Poon, A. W. P., Radford, D. C., Rager, J., Reine, A. L., Rielage, K., Ruof, N. W., Stortini, M. J., Tedeschi, D., Varner, R. L., Wilkerson, J. F., Wiseman, C., Xu, W., Yu, C. -H., and Zhu, B. X.

Subjects
Nuclear Experiment
Abstract

The MAJORANA DEMONSTRATOR is searching for double-beta decay of $^{76}$Ge to excited states (E.S.) in $^{76}$Se using a modular array of high purity Germanium detectors. $^{76}$Ge can decay into three E.S.s of $^{76}$Se. The E.S. decays have a clear event signature consisting of a $\beta\beta$-decay with the prompt emission of one or two $\gamma$-rays, resulting in with high probability in a multi-site event. The granularity of the DEMONSTRATOR detector array enables powerful discrimination of this event signature from backgrounds. Using 21.3 kg-y of isotopic exposure, the DEMONSTRATOR has set world leading limits for each E.S. decay, with 90% CL lower half-life limits in the range of $(0.56-2.1)\cdot10^{24}$ y. In particular, for the $2\nu$ transition to the first $0^+$ E.S. of $^{76}$Se, a lower half-life limit of $0.68\cdot10^{24}$ at 90% CL was achieved.

Published
2019
Full Text
View/download PDF

39. Cosmogenic Neutron Production at the Sudbury Neutrino Observatory

Author

Aharmim, B., Ahmed, S. N., Anthony, A. E., Barros, N., Beier, E. W., Bellerive, A., Beltran, B., Bergevin, M., Biller, S. D., Bonventre, R., Boudjemline, K., Boulay, M. G., Cai, B., Callaghan, E. J., Caravaca, J., Chan, Y. D., Chauhan, D., Chen, M., Cleveland, B. T., Cox, G. A., Curley, R., Dai, X., Deng, H., Descamps, F. B., Detwiler, J. A., Doe, P. J., Doucas, G., Drouin, P. -L., Dunford, M., Elliott, S. R., Evans, H. C., Ewan, G. T., Farine, J., Fergani, H., Fleurot, F., Ford, R. J., Formaggio, J. A., Gagnon, N., Gilje, K., Goon, J. TM., Graham, K., Guillian, E., Habib, S., Hahn, R. L., Hallin, A. L., Hallman, E. D., Harvey, P. J., Hazama, R., Heintzelman, W. J., Heise, J., Helmer, R. L., Hime, A., Howard, C., Huang, M., Jagam, P., Jamieson, B., Jelley, N. A., Jerkins, M., Kéfélian, C., Keeter, K. J., Klein, J. R., Kormos, L. L., Kos, M., Kr\u, A., Kraus, C., Krauss, C. B., Kutter, T., Kyba, C. C. M., Land, B. J., Lange, R., Law, J., Lawson, I. T., Lesko, K. T., Leslie, J. R., Levine, I., Loach, J. C., MacLellan, R., Majerus, S., Mak, H. B., Maneira, J., Martin, R. D., Mastbaum, A., McCauley, N., McDonald, A. B., McGee, S. R., Miller, M. L., Monreal, B., Monroe, J., Nickel, B. G., Noble, A. J., O'Keeffe, H. M., Oblath, N. S., Okada, C. E., Ollerhead, R. W., Gann, G. D. Orebi, Oser, S. M., Ott, R. A., Peeters, S. J. M., Poon, A. W. P., Prior, G., Reitzner, S. D., Rielage, K., Robertson, B. C., Robertson, R. G. H., Schwendener, M. H., Secrest, J. A., Seibert, S. R., Simard, O., Sinclair, D., Skensved, P., Sonley, T. J., Stonehill, L. C., Teš, G., Tolich, N., Tsui, T., Van Berg, R., VanDevender, B. A., Virtue, C. J., Wall, B. L., Waller, D., Tseung, H. Wan Chan, Wark, D. L., Wendland, J., West, N., Wilkerson, J. F., Wilson, J. R., Winchester, T., Wright, A., Yeh, M., Zhang, F., and Zuber, K.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

Neutrons produced in nuclear interactions initiated by cosmic-ray muons present an irreducible background to many rare-event searches, even in detectors located deep underground. Models for the production of these neutrons have been tested against previous experimental data, but the extrapolation to deeper sites is not well understood. Here we report results from an analysis of cosmogenically produced neutrons at the Sudbury Neutrino Observatory. A specific set of observables are presented, which can be used to benchmark the validity of GEANT4 physics models. In addition, the cosmogenic neutron yield, in units of $10^{-4}\;\text{cm}^{2}/\left(\text{g}\cdot\mu\right)$, is measured to be $7.28 \pm 0.09\;\text{stat.} ^{+1.59}_{-1.12}\;\text{syst.}$ in pure heavy water and $7.30 \pm 0.07\;\text{stat.} ^{+1.40}_{-1.02}\;\text{syst.}$ in NaCl-loaded heavy water. These results provide unique insights into this potential background source for experiments at SNOLAB.

Published
2019
Full Text
View/download PDF

40. Measurement of neutron production in atmospheric neutrino interactions at the Sudbury Neutrino Observatory

Author

SNO Collaboration, Aharmim, B., Ahmed, S. N., Anthony, A. E., Barros, N., Beier, E. W., Bellerive, A., Beltran, B., Bergevin, M., Biller, S. D., Bonventre, R., Boudjemline, K., Boulay, M. G., Cai, B., Callaghan, E. J., Caravaca, J., Chan, Y. D., Chauhan, D., Chen, M., Cleveland, B. T., Cox, G. A., Dai, X., Deng, H., Descamps, F. B., Detwiler, J. A., Doe, P. J., Doucas, G., Drouin, P. -L., Dunford, M., Elliott, S. R., Evans, H. C., Ewan, G. T., Farine, J., Fergani, H., Fleurot, F., Ford, R. J., Formaggio, J. A., Gagnon, N., Gilje, K., Goon, J. TM., Graham, K., Guillian, E., Habib, S., Hahn, R. L., Hallin, A. L., Hallman, E. D., Harvey, P. J., Hazama, R., Heintzelman, W. J., Heise, J., Helmer, R. L., Hime, A., Howard, C., Huang, M., Jagam, P., Jamieson, B., Jelley, N. A., Jerkins, M., Keeter, K. J., Klein, J. R., Kormos, L. L., Kos, M., Kruger, A., Kraus, C., Krauss, C. B., Kutter, T., Kyba, C. C. M., Land, B. J., Lange, R., Law, J., Lawson, I. T., Lesko, K. T., Leslie, J. R., Levine, I., Loach, J. C., MacLellan, R., Majerus, S., Mak, H. B., Maneira, J., Martin, R. D., Mastbaum, A., McCauley, N., McDonald, A. B., McGee, S. R., Miller, M. L., Monreal, B., Monroe, J., Nickel, B. G., Noble, A. J., O'Keeffe, H. M., Oblath, N. S., Okada, C. E., Ollerhead, R. W., Gann, G. D. Orebi, Oser, S. M., Ott, R. A., Peeters, S. J. M., Poon, A. W. P., Prior, G., Reitzner, S. D., Rielage, K., Robertson, B. C., Robertson, R. G. H., Schwendener, M. H., Secrest, J. A., Seibert, S. R., Simard, O., Sinclair, D., Singh, J., Skensved, P., Smiley, M., Sonley, T. J., Stonehill, L. C., Tesic, G., Tolich, N., Tsui, T., Van Berg, R., VanDevender, B. A., Virtue, C. J., Wall, B. L., Waller, D., Tseung, H. Wan Chan, Wark, D. L., Wendland, J., West, N., Wilkerson, J. F., Wilson, J. R., Winchester, T., Wright, A., Yeh, M., Zhang, F., and Zuber, K.

Subjects
High Energy Physics - Experiment
Abstract

Neutron production in GeV-scale neutrino interactions is a poorly studied process. We have measured the neutron multiplicities in atmospheric neutrino interactions in the Sudbury Neutrino Observatory experiment and compared them to the prediction of a Monte Carlo simulation using GENIE and a minimally modified version of GEANT4. We analyzed 837 days of exposure corresponding to Phase I, using pure heavy water, and Phase II, using a mixture of Cl in heavy water. Neutrons produced in atmospheric neutrino interactions were identified with an efficiency of $15.3\%$ and $44.3\%$, for Phase I and II respectively. The neutron production is measured as a function of the visible energy of the neutrino interaction and, for charged current quasi-elastic interaction candidates, also as a function of the neutrino energy. This study is also performed classifying the complete sample into two pairs of event categories: charged current quasi-elastic and non charged current quasi-elastic, and $\nu_{\mu}$ and $\nu_e$. Results show good overall agreement between data and Monte Carlo for both phases, with some small tension with a statistical significance below $2\sigma$ for some intermediate energies.

Published
2019
Full Text
View/download PDF

41. A Search for Neutrinoless Double-Beta Decay in $^{76}$Ge with 26 kg-yr of Exposure from the MAJORANA DEMONSTRATOR

Author

Alvis, S. I., Arnquist, I. J., Avignone III, F. T., Barabash, A. S., Barton, C. J., Basu, V., Bertrand, F. E., Bos, B., Busch, M., Buuck, M., Caldwell, T. S., Chan, Y-D., Christofferson, C. D., Chu, P. -H., Cuesta, C., Detwiler, J. A., Efremenko, Yu., Ejiri, H., Elliott, S. R., Gilliss, T., Giovanetti, G. K., Green, M. P., Gruszko, J., Guinn, I. S., Guiseppe, V. E., Haufe, C. R., Hegedus, R. J., Hehn, L., Henning, R., Aguilar, D. Hervas, Hoppe, E. W., Howe, M. A., Kidd, M. F., Konovalov, S. I., Kouzes, R. T., Lopez, A. M., Martin, R. D., Massarczyk, R., Meijer, S. J., Mertens, S., Myslik, J., Othman, G., Pettus, W., Piliounis, A., Poon, A. W. P., Radford, D. C., Rager, J., Reine, A. L., Rielage, K., Ruof, N. W., Shanks, B., Shirchenko, M., Tedeschi, D., Varner, R. L., Vasilyev, S., White, B. R., Wilkerson, J. F., Wiseman, C., Xu, W., Yakushev, E., Yu, C. -H., Yumatov, V., Zhitnikov, I., and Zhu, B. X.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

The MAJORANA Collaboration is operating an array of high purity Ge detectors to search for the neutrinoless double-beta decay of $^{76}$Ge. The MAJORANA DEMONSTRATOR consists of 44.1 kg of Ge detectors (29.7 kg enriched to 88% in $^{76}$Ge) split between two modules constructed from ultra-clean materials. Both modules are contained in a low-background shield at the Sanford Underground Research Facility in Lead, South Dakota. We present updated results on the search for neutrinoless double-beta decay in $^{76}$Ge with $26.0\pm0.5$ kg-yr of enriched exposure. With the DEMONSTRATOR's unprecedented energy resolution of 2.53 keV FWHM at $Q_{\beta\beta}$, we observe one event in the region of interest with 0.65 events expected from the estimated background, resulting in a lower limit on the $^{76}$Ge neutrinoless double-beta decay half-life of $2.7\times10^{25}$ yr (90% CL) with a median sensitivity of $4.8\times10^{25}$ yr (90% CL). Depending on the matrix elements used, a 90% CL upper limit on the effective Majorana neutrino mass in the range of 200-433 meV is obtained. The measured background in the low-background configurations is $11.9\pm2.0$ counts/(FWHM t yr)., Comment: 11 pages, 11 figures

Published
2019
Full Text
View/download PDF

42. Multi-site event discrimination for the MAJORANA DEMONSTRATOR

Author

Alvis, S. I., Arnquist, I. J., Avignone III, F. T., Barabash, A. S., Barton, C. J., Bertrand, F. E., Bos, B., Buuck, M., Caldwell, T. S., Chan, Y-D., Christofferson, C. D., Chu, P. -H., Cuesta, C., Detwiler, J. A., Ejiri, H., Elliott, S. R., Gilliss, T., Giovanetti, G. K., Green, M. P., Gruszko, J., Guinn, I. S., Guiseppe, V. E., Haufe, C. R., Hegedus, R. J., Hehn, L., Henning, R., Aguilar, D. Hervas, Hoppe, E. W., Howe, M. A., Keeter, K. J., Kidd, M. F., Konovalov, S. I., Kouzes, R. T., Lopez, A. M., Martin, R. D., Massarczyk, R., Meijer, S. J., Mertens, S., Myslik, J., Othman, G., Pettus, W., Piliounis, A., Poon, A. W. P., Radford, D. C., Rager, J., Reine, A. L., Rielage, K., Ruof, N. W., Shanks, B., Shirchenko, M., Tedeschi, D., Varner, R. L., Vasilyev, S., Vasundhara, White, B. R., Wilkerson, J. F., Wiseman, C., Xu, W., Yakushev, E., Yu, C. -H., Yumatov, V., Zhitnikov, I., and Zhu, B. X.

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

The MAJORANA DEMONSTRATOR is searching for neutrinoless double-beta decay in 76Ge using arrays of point-contact germanium detectors operating at the Sanford Underground Research Facility. Background results in the neutrinoless double-beta decay region of interest from data taken during construction, commissioning, and the start of full operations have been recently published. A pulse shape analysis cut applied to achieve this result, named AvsE, is described in this paper. This cut is developed to remove events whose waveforms are typical of multi-site energy deposits while retaining (90 +/- 3.5)% of single-site events. This pulse shape discrimination is based on the relationship between the maximum current and energy, and tuned using 228Th calibration source data. The efficiency uncertainty accounts for variation across detectors, energy, and time, as well as for the position distribution difference between calibration and $0\nu\beta\beta$ events, established using simulations., Comment: 8 pages, 8 figures

Published
2019
Full Text
View/download PDF

43. $α$-event Characterization and Rejection in Point-Contact HPGe Detectors

Author

Collaboration, The MAJORANA, Arnquist, IJ, III, FT Avignone, Barabash, AS, Barton, CJ, Bertrand, FE, Blalock, E, Bos, B, Busch, M, Buuck, M, Caldwell, TS, Chan, Y-D, Christofferson, CD, Chu, P-H, Clark, ML, Cuesta, C, Detwiler, JA, Drobizhev, A, Edwards, TR, Edwins, DW, Efremenko, Yu, Elliott, SR, Gilliss, T, Giovanetti, GK, Green, MP, Gruszko, J, Guinn, IS, Guiseppe, VE, Haufe, CR, Hegedus, RJ, Henning, R, Aguilar, D Hervas, Hoppe, EW, Hostiuc, A, Kim, I, Kouzes, RT, Lopez, AM, López-Castaño, JM, Martin, EL, Martin, RD, Massarczyk, R, Meijer, SJ, Mertens, S, Myslik, J, Oli, TK, Othman, G, Pettus, W, Poon, AWP, Radford, DC, Rager, J, Reine, AL, Rielage, K, Ruof, NW, Saykı, B, önert, S Sch, Stortini, MJ, Tedeschi, D, Varner, RL, Vasilyev, S, Wilkerson, JF, Willers, M, Wiseman, C, Xu, W, Yu, C-H, and Zhu, BX

Subjects
physics.ins-det, hep-ex, nucl-ex
Abstract

P-type point contact (PPC) HPGe detectors are a leading technology for rareevent searches due to their excellent energy resolution, low thresholds, andmulti-site event rejection capabilities. We have characterized a PPC detector'sresponse to $\alpha$ particles incident on the sensitive passivated and p+surfaces, a previously poorly-understood source of background. The detectorstudied is identical to those in the MAJORANA DEMONSTRATOR experiment, a searchfor neutrinoless double-beta decay ($0u\beta\beta$) in $^{76}$Ge. $\alpha$decays on most of the passivated surface exhibit significant energy loss due tocharge trapping, with waveforms exhibiting a delayed charge recovery (DCR)signature caused by the slow collection of a fraction of the trapped charge.The DCR is found to be complementary to existing methods of $\alpha$identification, reliably identifying $\alpha$ background events on thepassivated surface of the detector. We demonstrate effective rejection of allsurface $\alpha$ events (to within statistical uncertainty) with a loss of only0.2% of bulk events by combining the DCR discriminator with previously-usedmethods. The DCR discriminator has been used to reduce the background rate inthe $0u\beta\beta$ region of interest window by an order of magnitude in theMAJORANA DEMONSTRATOR, and will be used in the upcoming LEGEND-200 experiment.

Published
2020

44. Results of the MAJORANA DEMONSTRATOR’s Search for Double-Beta Decay of 76Ge to Excited States of 76Se

Author

Guinn, IS, Arnquist, IJ, Avignone, FT, Barabash, AS, Barton, CJ, Bertrand, FE, Bos, B, Busch, M, Buuck, M, Caldwell, TS, Chan, Y-D, Christofferson, CD, Chu, P-H, Clark, ML, Cuesta, C, Detwiler, JA, Drobizhev, A, Edwins, DW, Efremenko, Yu, Ejiri, H, Elliott, SR, Gilliss, T, Giovanetti, GK, Green, MP, Gruszko, J, Guiseppe, VE, Haufe, CR, Hegedus, RJ, Henning, R, Aguilar, D Hervas, Hoppe, EW, Hostiuc, A, Kidd, MF, Kim, I, Kouzes, RT, Lopez, AM, López-Castaño, JM, Martin, EL, Martin, RD, Massarczyk, R, Meijer, SJ, Mertens, S, Myslik, J, Oli, TK, Othman, G, Pettus, W, Poon, AWP, Radford, DC, Rager, J, Reine, AL, Rielage, K, Ruof, NW, Stortini, MJ, Tedeschi, D, Varner, RL, Wilkerson, JF, Wiseman, C, Xu, W, Yu, C-H, and Zhu, BX

Subjects
nucl-ex, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Condensed Matter Physics, Other Physical Sciences
Abstract

The MAJORANA DEMONSTRATOR is searching for double-beta decay of 76Ge to excited states (E.S.) in 76Se using a modular array of high purity Germanium detectors. 76Ge can decay into three E.S.s of 76Se. The E.S. decays have a clear event signature consisting of a ββ-decay with the prompt emission of one or two γ-rays, resulting in with high probability in a multi-site event. The granularity of the DEMONSTRATOR detector array enables powerful discrimination of this event signature from backgrounds. Using 21.3 kg-y of isotopic exposure, the DEMONSTRATOR has set world leading limits for each E.S. decay, with 90% CL lower half-life limits in the range of (0.56 2.1) ⋅ 1024 y. In particular, for the 2v transition to the first 0+ E.S. of 76Se, a lower half-life limit of 0.68 ⋅ 1024 at 90% CL was achieved.

Published
2020

45. Data quality assurance for the Majorana Demonstrator

Author

Myslik, J, Abgrall, N, Alvis, SI, Arnquist, IJ, Avignone, FT, Barabash, AS, Barton, CJ, Bertrand, FE, Bode, T, Bradley, AW, Brudanin, V, Busch, M, Buuck, M, Caldwell, TS, Chan, Y-D, Christofferson, CD, Chu, P-H, Cuesta, C, Detwiler, JA, Dunagan, C, Efremenko, Yu, Ejiri, H, Elliott, SR, Gilliss, T, Giovanetti, GK, Green, MP, Gruszko, J, Guinn, IS, Guiseppe, VE, Haufe, CR, Hehn, L, Henning, R, Hoppe, EW, Howe, MA, Keeter, KJ, Kidd, MF, Konovalov, SI, Kouzes, RT, Lopez, AM, Martin, RD, Massarczyk, R, Meijer, SJ, Mertens, S, O’Shaughnessy, C, Othman, G, Pettus, W, Poon, AWP, Radford, DC, Rager, J, Reine, AL, Rielage, K, Robertson, RGH, Ruof, NW, Shanks, B, Shirchenko, M, Suriano, AM, Tedeschi, D, Trimble, JE, Varner, RL, Vasilyev, S, Vetter, K, Vorren, K, White, BR, Wilkerson, JF, Wiseman, C, Xu, W, Yakushev, E, Yu, C-H, Yumatov, V, Zhitnikov, I, and Zhu, BX

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, physics.ins-det, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Condensed Matter Physics, Other Physical Sciences, Physical sciences
Abstract

The MAJORANA DEMONSTRATOR is an experiment constructed to search for neutrinoless double-beta decays in germanium-76 and to demonstrate the feasibility to deploy a large-scale experiment in a phased and modular fashion. It consists of two modular arrays of natural and 76 Ge-enriched germanium detectors totalling 44.1 kg, located at the 4850' level of the Sanford Underground Research Facility in Lead, South Dakota, USA. Any neutrinoless double-beta decay search requires a thorough understanding of the background and the signal energy spectra. The various techniques employed to ensure the integrity of the measured spectra are discussed. Data collection is monitored with a thorough set of checks, and subsequent careful analysis is performed to qualify the data for higher level physics analysis. Instrumental background events are tagged for removal, and problematic channels are removed from consideration as necessary.

Published
2020

46. Progress Toward A 2νββ Measurement For The Majorana Demonstrator

Author

Gilliss, T, Abgrall, N, Alvis, SI, Arnquist, IJ, Avignone, FT, Barabash, AS, Barton, CJ, Bertrand, FE, Bode, T, Bradley, AW, Brudanin, V, Busch, M, Buuck, M, Caldwell, TS, Chan, Y-D, Christofferson, CD, Chu, P-H, Cuesta, C, Detwiler, JA, Dunagan, C, Efremenko, Yu, Ejiri, H, Elliott, SR, Giovanetti, GK, Green, MP, Gruszko, J, Guinn, IS, Guiseppe, VE, Haufe, CR, Hehn, L, Henning, R, Hoppe, EW, Howe, MA, Keeter, KJ, Kidd, MF, Konovalov, SI, Kouzes, RT, Lopez, AM, Martin, RD, Massarczyk, R, Meijer, SJ, Mertens, S, Myslik, J, O’Shaughnessy, C, Othman, G, Pettus, W, Poon, AWP, Radford, DC, Rager, J, Reine, AL, Rielage, K, Robertson, RGH, Ruof, NW, Shanks, B, Shirchenko, M, Suriano, AM, Tedeschi, D, Trimble, JE, Varner, RL, Vasilyev, S, Vetter, K, Vorren, K, White, BR, Wilkerson, JF, Wiseman, C, Xu, W, Yakushev, E, Yu, C-H, Yumatov, V, Zhitnikov, I, and Zhu, BX

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, physics.ins-det, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Condensed Matter Physics, Other Physical Sciences, Physical sciences
Abstract

The MAJORANA DEMONSTRATOR is a 76Ge-based neutrinoless double-beta decay (0νββ) experiment. Staged at the 4850 ft level of the Sanford Underground Research Facility, the DEMONSTRATOR operates an array of high-purity p-Type point contact Ge detectors deployed within a graded passive shield and an active muon veto system. The present work concerns the two-neutrino double-beta decay mode (2νββ) of 76Ge. For Ge detectors, having superior energy resolution (0.1%), this mode poses negligible background to the 0νββ mode, even for a ton-scale experiment. However, the measurement of the 2νββ mode allows for careful systematics checks of active detector mass, enrichment fraction, and pulse shape discrimination cuts related to both the 0νββ and 2νββ decay modes. A precision measurement of the 2νββ shape also allows searches for spectral distortions, possibly indicative of new physics, including 0νββχ. Work is underway to construct a full experimental background model enabling a Bayesian fit to the measured energy spectrum and extraction of a precise 2νββ spectrum and half-life.

Published
2020

47. Spectral analysis for the Majorana Demonstrator experiment

Author

Hehn, L, Abgrall, N, Alvis, SI, Arnquist, IJ, Avignone, FT, Barabash, AS, Barton, CJ, Bertrand, FE, Bode, T, Bradley, AW, Brudanin, V, Busch, M, Buuck, M, Caldwell, TS, Chan, Y-D, Christofferson, CD, Chu, P-H, Cuesta, C, Detwiler, JA, Dunagan, C, Efremenko, Yu, Ejiri, H, Elliott, SR, Gilliss, T, Giovanetti, GK, Green, MP, Gruszko, J, Guinn, IS, Guiseppe, VE, Haufe, CR, Henning, R, Hoppe, EW, Howe, MA, Keeter, KJ, Kidd, MF, Konovalov, SI, Kouzes, RT, Lopez, AM, Martin, RD, Massarczyk, R, Meijer, SJ, Mertens, S, Myslik, J, O’Shaughnessy, C, Othman, G, Pettus, W, Poon, AWP, Radford, DC, Rager, J, Reine, AL, Rielage, K, Robertson, RGH, Ruof, NW, Shanks, B, Shirchenko, M, Suriano, AM, Tedeschi, D, Trimble, JE, Varner, RL, Vasilyev, S, Vetter, K, Vorren, K, White, BR, Wilkerson, JF, Wiseman, C, Xu, W, Yakushev, E, Yu, C-H, Yumatov, V, Zhitnikov, I, and Zhu, BX

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, physics.ins-det, nucl-ex, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Condensed Matter Physics, Other Physical Sciences, Physical sciences
Abstract

The MAJORANA DEMONSTRATOR is an experiment constructed to search for neutrinoless double-beta decays in germanium-76 and to demonstrate the feasibility to deploy a ton-scale experiment in a phased and modular fashion. It consists of two modular arrays of natural and 76Ge-enriched germanium detectors totaling 44.1kg (29.7kg enriched detectors), located at the 4850' level of the Sanford Underground Research Facility in Lead, South Dakota, USA. Data taken with this setup since summer 2015 at different construction stages of the experiment show a clear reduction of the observed background index around the ROI for 0νββ-decay search due to improvements in shielding. We discuss the statistical approaches to search for a νββ-signal and derive the physics sensitivity for an expected exposure of 10kg• y from enriched detectors using a profile likelihood based hypothesis test in combination with toy Monte Carlo data.

Published
2020

48. Design improvements to cables and connectors in the Majorana Demonstrator

Author

Haufe, CR, Reine, AL, Abgrall, N, Alvis, SI, Arnquist, IJ, Avignone, FT, Barabash, AS, Barton, CJ, Bertrand, FE, Bode, T, Bradley, AW, Brudanin, V, Busch, M, Buuck, M, Caldwell, TS, Chan, Y-D, Christofferson, CD, Chu, P-H, Cuesta, C, Detwiler, JA, Dunagan, C, Efremenko, Yu, Ejiri, H, Elliott, SR, Gilliss, T, Giovanetti, GK, Green, MP, Gruszko, J, Guinn, IS, Guiseppe, VE, Hehn, L, Henning, R, Hoppe, EW, Howe, MA, Keeter, KJ, Kidd, MF, Konovalov, SI, Kouzes, RT, Lopez, AM, Martin, RD, Massarczyk, R, Meijer, SJ, Mertens, S, Myslik, J, O’Shaughnessy, C, Othman, G, Pettus, W, Poon, AWP, Radford, DC, Rager, J, Rielage, K, Robertson, RGH, Ruof, NW, Shanks, B, Shirchenko, M, Suriano, AM, Tedeschi, D, Trimble, JE, Varner, RL, Vasilyev, S, Vetter, K, Vorren, K, White, BR, Wilkerson, JF, Wiseman, C, Xu, W, Yakushev, E, Yu, C-H, Yumatov, V, Zhitnikov, I, and Zhu, BX

Subjects
Nuclear and Plasma Physics, Physical Sciences, physics.ins-det, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Condensed Matter Physics, Other Physical Sciences, Physical sciences
Abstract

The MAJORANA DEMONSTRATOR is an experiment constructed to search for neutrinoless double-beta decays in germanium-76 and to demonstrate the feasibility to deploy a ton-scale experiment in a phased and modular fashion. It consists of two modular arrays of natural and 76Ge-enriched germanium p-Type point contact detectors totaling 44.1 kg, located at the 4850' level of the Sanford Underground Research Facility in Lead, South Dakota, USA. The DEMONSTRATOR uses custom high voltage cables to bias the detectors, as well as custom signal cables and connectors to read out the charge deposited at each detectors point contact. These low-mass cables and connectors must meet stringent radiopurity requirements while being subjected to thermal and mechanical stress. A number of issues have been identified with the currently installed cables and connectors. An improved set of cables and connectors for the MAJORANA DEMONSTRATOR are being developed with the aim of increasing their overall reliability and connectivity. We will discuss some of the issues encountered with the current cables and connectors as well as our improved designs and their initial performance.

Published
2020

49. Recent results from the MAJORANA DEMONSTRATOR

Author

Myslik, J., Alvis, S. I., Arnquist, I. J., Avignone III, F. T., Barabash, A. S., Barton, C. J., Bertrand, F. E., Bode, T., Bos, B., Brudanin, V., Busch, M., Buuck, M., Caldwell, T. S., Chan, Y-D., Christofferson, C. D., Chu, P. -H., Cuesta, C., Detwiler, J. A., Dunagan, C., Efremenko, Yu., Ejiri, H., Elliott, S. R., Gilliss, T., Giovanetti, G. K., Green, M. P., Gruszko, J., Guinn, I. S., Guiseppe, V. E., Haufe, C. R., Hegedus, R. J., Hehn, L., Henning, R., Aguilar, D. Hervas, Hoppe, E. W., Howe, M. A., Keeter, K. J., Kidd, M. F., Konovalov, S. I., Kouzes, R. T., Lopez, A. M., Martin, R. D., Massarczyk, R., Meijer, S. J., Mertens, S., Othman, G., Pettus, W., Piliounis, A., Poon, A. W. P., Radford, D. C., Rager, J., Reine, A. L., Rielage, K., Ruof, N. W., Shanks, B., Shirchenko, M., Tedeschi, D., Varner, R. L., Vasilyev, S., Vasundhara, White, B. R., Wilkerson, J. F., Wiseman, C., Xu, W., Yakushev, E., Yu, C. -H., Yumatov, V., Zhitnikov, I., and Zhu, B. X.

Subjects
Physics - Instrumentation and Detectors, Nuclear Experiment
Abstract

The MAJORANA DEMONSTRATOR is an experiment constructed to search for neutrinoless double-beta decay in $^{76}$Ge and to demonstrate the feasibility to deploy a large-scale experiment in a phased and modular fashion. It consists of two modules of natural and $^{76}$Ge-enriched germanium detectors totalling 44.1 kg, operating at the 4850' level of the Sanford Underground Research Facility in Lead, South Dakota, USA. Commissioning of the experiment began in June 2015, followed by data production with the full detector array in August 2016. The ultra-low background and record energy resolution achieved by the MAJORANA DEMONSTRATOR enable a sensitive neutrinoless double-beta decay search, as well as additional searches for physics beyond the Standard Model. I will discuss the design elements that enable these searches, along with the latest results, focusing on the neutrinoless double-beta decay search. I will also discuss the current status and the future plans of the MAJORANA DEMONSTRATOR, as well as the plans for a future tonne-scale $^{76}$Ge experiment., Comment: 4 pages. Proceedings of The 39th International Conference on High Energy Physics (ICHEP2018), 4-11 July, 2018, Seoul, Korea. Submitted to Proceedings of Science

Published
2018

50. Constraints on Neutrino Lifetime from the Sudbury Neutrino Observatory

Author

SNO Collaboration, Aharmim, B., Ahmed, S. N., Anthony, A. E., Barros, N., Beier, E. W., Bellerive, A., Beltran, B., Bergevin, M., Biller, S. D., Bonventre, R., Boudjemline, K., Boulay, M. G., Cai, B., Callaghan, E. J., Caravaca, J., Chan, Y. D., Chauhan, D., Chen, M., Cleveland, B. T., Cox, G. A., Dai, X., Deng, H., Descamps, F. B., Detwiler, J. A., Doe, P. J., Doucas, G., Drouin, P. -L., Dunford, M., Elliott, S. R., Evans, H. C., Ewan, G. T., Farine, J., Fergani, H., Fleurot, F., Ford, R. J., Formaggio, J. A., Gagnon, N., Gilje, K., Goon, J. TM., Graham, K., Guillian, E., Habib, S., Hahn, R. L., Hallin, A. L., Hallman, E. D., Harvey, P. J., Hazama, R., Heintzelman, W. J., Heise, J., Helmer, R. L., Hime, A., Howard, C., Huang, M., Jagam, P., Jamieson, B., Jelley, N. A., Jerkins, M., Kéfélian, C., Keeter, K. J., Klein, J. R., Kormos, L. L., Kos, M., Krüger, A., Kraus, C., Krauss, C. B., Kutter, T., Kyba, C. C. M., Land, B. J., Lange, R., Law, J., Lawson, I. T., Lesko, K. T., Leslie, J. R., Levine, I., Loach, J. C., MacLellan, R., Majerus, S., Mak, H. B., Maneira, J., Martin, R. D., Mastbaum, A., McCauley, N., McDonald, A. B., McGee, S. R., Miller, M. L., Monreal, B., Monroe, J., Nickel, B. G., Noble, A. J., O'Keeffe, H. M., Oblath, N. S., Okada, C. E., Ollerhead, R. W., Gann, G. D. Orebi, Oser, S. M., Ott, R. A., Peeters, S. J. M., Poon, A. W. P., Prior, G., Reitzner, S. D., Rielage, K., Robertson, B. C., Robertson, R. G. H., Schwendener, M. H., Secrest, J. A., Seibert, S. R., Simard, O., Sinclair, D., Skensved, P., Sonley, T. J., Stonehill, L. C., Tešić, G., Tolich, N., Tsui, T., Van Berg, R., VanDevender, B. A., Virtue, C. J., Wall, B. L., Waller, D., Tseung, H. Wan Chan, Wark, D. L., Wendland, J., West, N., Wilkerson, J. F., Wilson, J. R., Winchester, T., Wright, A., Yeh, M., Zhang, F., and Zuber, K.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

The long baseline between the Earth and the Sun makes solar neutrinos an excellent test beam for exploring possible neutrino decay. The signature of such decay would be an energy-dependent distortion of the traditional survival probability which can be fit for using well-developed and high precision analysis methods. Here a model including neutrino decay is fit to all three phases of $^8$B solar neutrino data taken by the Sudbury Neutrino Observatory. This fit constrains the lifetime of neutrino mass state $\nu_2$ to be ${>8.08\times10^{-5}}$ s/eV at $90\%$ confidence. An analysis combining this SNO result with those from other solar neutrino experiments results in a combined limit for the lifetime of mass state $\nu_2$ of ${>1.04\times10^{-3}}$ s/eV at $99\%$ confidence.

Published
2018
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results