First Direct-Detection Results on Sub-GeV Dark Matter Using the SENSEI Detector at SNOLAB
Prakruth Adari, Itay M. Bloch, Ana Martina Botti, Mariano Cababié, Gustavo Cancelo, Brenda A. Cervantes-Vergara, M. B. Crisler, M. Daal, Ansh Desai, A. Drlica-Wagner, Rouven Essig, J. Estrada, E. Etzion, Guillermo Fernández Moroni, S. Holland, Jonathan Kehat, Yaron Korn, Ian Lawson, Steffon Luoma, Aviv Orly, Santiago Pérez, Darío Rodrigues, N. Saffold, S. Scorza, Aman Singal, Miguel Sofo-Haro, Leandro Stefanazzi, Kelly Stifter, Javier Tiffenberg, Sho Uemura, Edgar Marrufo Villalpando, Tomer Volansky, Yikai Wu, T. Yu, Timón Emken, Hailin Xu
Abstract
We present the first results from a dark matter search using six Skipper-CCDs in the SENSEI detector operating at SNOLAB. We employ a bias-mitigation technique of hiding approximately 46% of our total data and aggressively mask images to remove backgrounds. Given a total exposure after masking of 100.72 gram-days from well-performing sensors, we observe 55 two-electron events, 4 three-electron events, and no events containing 4-10 electrons. The two-electron events are consistent with pileup from one-electron events. Among the 4 three-electron events, 2 appear in pixels that are likely impacted by detector defects, although not strongly enough to trigger our "hot-pixel" mask. We use these data to set world-leading constraints on sub-GeV dark matter interacting with electrons and nuclei.