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Your search keyword '"Agartioglu, M."' showing total 4 results
Start Over Author "Agartioglu, M." Topic dark matter
4 results on '"Agartioglu, M."'

1. Constraints on millicharged particles with low-threshold germanium detectors at Kuo-Sheng Reactor Neutrino Laboratory

Author

TEXONO Collaboration, Singh, L., Chen, J. W., Chi, H. C., Liu, C. -P., Pandey, M. K., Wong, H. T., Wu, C. P., Agartioglu, M., Deniz, M., Li, H. B., Lin, S. T., Sharma, V., Singh, M. K., Singh, V., Yue, Q., Massachusetts Institute of Technology. Center for Theoretical Physics, Massachusetts Institute of Technology. Department of Physics, and Chen, J. W.

Subjects
Shock wave, Physics, Photon, Astrophysics::High Energy Astrophysical Phenomena, Dark matter, FOS: Physical sciences, High Energy Physics - Experiment, Standard Model, Semiconductor detector, Nuclear physics, High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology, Supernova, High Energy Physics - Phenomenology (hep-ph), Nuclear reactor core, Ionization
Abstract

Relativistic millicharged particles ($\chi_q$) have been proposed in various extensions to the Standard Model of particle physics. We consider the scenarios where they are produced at nuclear reactor core and via interactions of cosmic-rays with the earth's atmosphere. Millicharged particles could also be candidates for dark matter, and become relativistic through acceleration by supernova explosion shock waves. The atomic ionization cross section of $\chi_q$ with matter are derived with the equivalent photon approximation. Smoking-gun signatures with significant enhancement in the differential cross section are identified. New limits on the mass and charge of $\chi_q$ are derived, using data taken with a point-contact germanium detector with 500g mass functioning at an energy threshold of 300~eV at the Kuo-Sheng Reactor Neutrino Laboratory., Comment: 8 pages, 7 figures

Published
2019

2. Bulk and surface event identification in p-type germanium detectors.

Author

Yang, L.T., Li, H.B., Wong, H.T., Agartioglu, M., Chen, J.H., Jia, L.P., Jiang, H., Li, J., Lin, F.K., Lin, S.T., Liu, S.K., Ma, J.L., Sevda, B., Sharma, V., Singh, L., Singh, M.K., Soma, A.K., Sonay, A., Yang, S.W., and Wang, L.

Subjects
*GERMANIUM detectors, *WEAKLY interacting massive particle detectors, *NEUTRINOS, *DARK matter, *SPECTRAL energy distribution
Abstract

The p-type point-contact germanium detectors have been adopted for light dark matter WIMP searches and the studies of low energy neutrino physics. These detectors exhibit anomalous behavior to events located at the surface layer. The previous spectral shape method to identify these surface events from the bulk signals relies on spectral shape assumptions and the use of external calibration sources. We report an improved method in separating them by taking the ratios among different categories of in situ event samples as calibration sources. Data from CDEX-1 and TEXONO experiments are re-examined using the ratio method. Results are shown to be consistent with the spectral shape method. [ABSTRACT FROM AUTHOR]

Published
2018
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3. Characterization and performance of germanium detectors with sub-keV sensitivities for neutrino and dark matter experiments.

Author

Soma, A.K., Singh, M.K., Singh, L., Kumar, G. Kiran, Lin, F.K., Du, Q., Jiang, H., Liu, S.K., Ma, J.L., Sharma, V., Wang, L., Wu, Y.C., Yang, L.T., Zhao, W., Agartioglu, M., Asryan, G., Chang, Y.Y., Chen, J.H., Chuang, Y.C., and Deniz, M.

Subjects
*GERMANIUM detectors, *NEUTRINOS, *IONIZATION (Atomic physics), *QUENCHING (Chemistry), *ELECTRONIC noise, *QUANTUM efficiency
Abstract

Germanium ionization detectors with sensitivities as low as 100 eV ee (electron-equivalent energy) open new windows for studies on neutrino and dark matter physics. The relevant physics subjects are summarized. The detectors have to measure physics signals whose amplitude is comparable to that of pedestal electronic noise. To fully exploit this new detector technique, various experimental issues including quenching factors, energy reconstruction and calibration, signal triggering and selection as well as evaluation of their associated efficiencies have to be attended. The efforts and results of a research program to address these challenges are presented. [ABSTRACT FROM AUTHOR]

Published
2016
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4. Differentiation of bulk and surface events in p-type point-contact germanium detectors for light WIMP searches.

Author

Li, H.B., Singh, L., Singh, M.K., Soma, A.K., Tseng, C.H., Yang, S.W., Agartioglu, M., Asryan, G., Chuang, Y.C., Deniz, M., Huang, T.R., Kiran Kumar, G., Li, J., Liao, H.Y., Lin, F.K., Lin, S.T., Liu, S.K., Sharma, V., Shen, Y.T., and Singh, V.

Subjects
*SURFACES (Technology), *P-type semiconductors, *GERMANIUM detectors, *NEUTRINOS, *DARK matter, *WEAKLY interacting massive particles
Abstract

Abstract: The p-type point-contact germanium detectors are novel techniques offering kg-scale radiation sensors with sub-keV sensitivities. They have been used for light dark matter WIMPs searches and may have potential applications in neutrino physics. There are, however, anomalous surface behaviour which needs to be characterized and understood. We describe the methods and results of a research program whose goals are to identify the bulk and surface events via software pulse shape analysis techniques, and to devise calibration schemes to evaluate the selection efficiency factors. Efficiencies-corrected background spectra from the low-background facility at Kuo-Sheng Neutrino Laboratory are derived. [Copyright &y& Elsevier]

Published
2014
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