G.H. Yu, N. Carlin, J.Y. Cho, J.J. Choi, S. Choi, A.C. Ezeribe, L.E. França, C. Ha, I.S. Hahn, S.J. Hollick, E.J. Jeon, H.W. Joo, W.G. Kang, M. Kauer, B.H. Kim, H.J. Kim, J. Kim, K.W. Kim, S.H. Kim, S.K. Kim, W.K. Kim, Y.D. Kim, Y.H. Kim, Y.J. Ko, D.H. Lee, E.K. Lee, H. Lee, H.Y. Lee, I.S. Lee, J. Lee, J.Y. Lee, M.H. Lee, S.H. Lee, S.M. Lee, Y.J. Lee, D.S. Leonard, N.T. Luan, V.H.A. Machado, B.B. Manzato, R.H. Maruyama, R.J. Neal, S.L. Olsen, B.J. Park, H.K. Park, H.S. Park, J.C. Park, K.S. Park, S.D. Park, R.L.C. Pitta, H. Prihtiadi, S.J. Ra, C. Rott, K.A. Shin, D.F.F.S. Cavalcante, M.K. Son, N.J.C. Spooner, L.T. Truc, L. Yang
We report limits on weakly interacting massive particle (WIMP) dark matter derived from three years of data collected by the COSINE-100 experiment with NaI(Tl) crystals, achieving an improved energy threshold of 0.7 keV. This lowered threshold enhances sensitivity in the sub-GeV mass range, extending the reach for direct detection of low-mass dark matter. Although no excess of WIMP-like events was observed, the increased sensitivity enabled a model-insensitive comparison between the expected WIMP signal rate—based on mass limits from our data—and DAMA’s reported modulation amplitude. Our findings strongly disfavor the DAMA signal as originating from WIMP interactions, fully excluding DAMA/LIBRA 3σ allowed regions and providing enhanced WIMP mass limits by an order of magnitude in the spin-independent model compared to previous results. In the spin-dependent model, cross-section upper limits were obtained in the mass range [0.1–5.0] GeV/c2, with additional sensitivity to sub-GeV WIMPs through the inclusion of the Migdal effect. These results represent substantial progress in low-mass dark matter exploration and reinforce constraints on the longstanding DAMA claim. © 2025 authors. Published by the American Physical Society.
Department of Physics, Sungkyunkwan University, Suwon, 16419, South Korea; Center for Underground Physics, Institute for Basic Science (IBS), Daejeon, 34126, South Korea; Physics Institute, University of São Paulo, São Paulo, 05508-090, Brazil; Department of Physics, Kyungpook National University, Daegu, 41566, South Korea; Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea; Department of Physics and Astronomy, University of Sheffield, Sheffield, S3 7RH, United Kingdom; Department of Physics, Chung-Ang University, Seoul, 06973, South Korea; Center for Exotic Nuclear Studies, Institute for Basic Science (IBS), Daejeon, 34126, South Korea; Department of Science Education, Ewha Womans University, Seoul, 03760, South Korea; IBS School, University of Science and Technology (UST), Daejeon, 34113, South Korea; Department of Physics, Wright Laboratory, Yale University, New Haven, 06520, CT, United States; Department of Physics, Wisconsin IceCube Particle Astrophysics Center, University of Wisconsin-Madison, Madison, 53706, WI, United States; Department of Accelerator Science, Korea University, Sejong, 30019, South Korea; Korea Research Institute of Standards and Science, Daejeon, 34113, South Korea; Department of Physics and IQS, Chungnam National University, Daejeon, 34134, South Korea; Department of Physics, Universitas Negeri Malang, Malang, 65145, Indonesia; Department of Physics and Astronomy, University of Utah, Salt Lake City, 84112, UT, United States; Department of Physics, University of California San Diego, La Jolla, 92093, CA, United States
