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 to 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.
@article{arxiv.2312.13342,
title = {SENSEI: First Direct-Detection Results on sub-GeV Dark Matter from SENSEI at SNOLAB},
author = {SENSEI Collaboration and Prakruth Adari and Itay M. Bloch and Ana M. Botti and Mariano Cababie and Gustavo Cancelo and Brenda A. Cervantes-Vergara and Michael Crisler and Miguel Daal and Ansh Desai and Alex Drlica-Wagner and Rouven Essig and Juan Estrada and Erez Etzion and Guillermo Fernandez Moroni and Stephen E. Holland and Jonathan Kehat and Yaron Korn and Ian Lawson and Steffon Luoma and Aviv Orly and Santiago E. Perez and Dario Rodrigues and Nathan A. Saffold and Silvia Scorza and Aman Singal and Miguel Sofo-Haro and Leandro Stefanazzi and Kelly Stifter and Javier Tiffenberg and Sho Uemura and Edgar Marrufo Villalpando and Tomer Volansky and Yikai Wu and Tien-Tien Yu and Timon Emken and Hailin Xu},
journal= {arXiv preprint arXiv:2312.13342},
year = {2025}
}
Comments
6 pages, 2 figures, + Supplemental Materials (5 pages, 6 figures) + References. v2: Minor clarifications, matches version published in PRL