학술논문
Confirmation of the spectral excess in DAMIC at SNOLAB with skipper CCDs
Document Type
Working Paper
Author
Aguilar-Arevalo, A.; Arnquist, I.; Avalos, N.; Barak, L.; Baxter, D.; Bertou, X.; Bloch, I. M.; Botti, A. M.; Cababie, M.; Cancelo, G.; Castelló-Mor, N.; Cervantes-Vergara, B. A.; Chavarria, A. E.; Cortabitarte-Gutiérrez, J.; Crisler, M.; Cuevas-Zepeda, J.; Dastgheibi-Fard, A.; De Dominicis, C.; Deligny, O.; Drlica-Wagner, A.; Duarte-Campderros, J.; D'Olivo, J. C.; Essig, R.; Estrada, E.; Estrada, J.; Etzion, E.; Favela-Perez, F.; Gadola, N.; Gaïor, R.; Holland, S. E.; Hossbach, T.; Iddir, L.; Kilminster, B.; Korn, Y.; Lantero-Barreda, A.; Lawson, I.; Lee, S.; Letessier-Selvon, A.; Loaiza, P.; Lopez-Virto, A.; Luoma, S.; Marrufo-Villalpando, E.; McGuire, K. J.; Moroni, G. F.; Munagavalasa, S.; Norcini, D.; Orly, A.; Papadopoulos, G.; Paul, S.; Perez, S. E.; Piers, A.; Privitera, P.; Robmann, P.; Rodrigues, D.; Saffold, N. A.; Scorza, S.; Settimo, M.; Singal, A.; Smida, R.; Sofo-Haro, M.; Stefanazzi, L.; Stifter, K.; Tiffenberg, J.; Traina, M.; Uemura, S.; Vila, I.; Vilar, R.; Volansky, T.; Warot, G.; Yajur, R.; Yu, T-T.; Zopounidis, J-P.
Source
Phys. Rev. D 109, 062007 (2024)
Subject
Language
Abstract
We present results from a 3.25 kg-day target exposure of two silicon charge-coupled devices (CCDs), each with 24 megapixels and skipper readout, deployed in the DAMIC setup at SNOLAB. With a reduction in pixel readout noise of a factor of 10 relative to the previous detector, we investigate the excess population of low-energy events in the CCD bulk previously observed above expected backgrounds. We address the dominant systematic uncertainty of the previous analysis through a depth fiducialization designed to reject surface backgrounds on the CCDs. The measured bulk ionization spectrum confirms the presence of an excess population of low-energy events in the CCD target with characteristic rate of ${\sim}7$ events per kg-day and electron-equivalent energies of ${\sim}80~$eV, whose origin remains unknown.
Comment: 8 pages, 4 figures
Comment: 8 pages, 4 figures