G. Adhikari, 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, S.W. Kim, W.K. Kim, Y.D. Kim, Y.H. Kim, Y.J. Ko, D.H. Lee, E.K. Lee, H. Lee, H.S. 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, B.B. Manzato, R.H. Maruyama, R.J. Neal, J.A. Nikkel, 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, A. Scarff, M.K. Son, N.J.C. Spooner, L.T. Truc, L. Yang, G.H. Yu
We report the results of a search for inelastic scattering of weakly interacting massive particles (WIMPs) off I127 nuclei using NaI(Tl) crystals with a data exposure of 97.7 kg·years from the COSINE-100 experiment. The signature of inelastic WIMP-I127 scattering is a nuclear recoil accompanied by a 57.6 keV γ-ray from the prompt deexcitation, producing a more energetic signal compared to the typical WIMP nuclear recoil signal. We found no evidence for this inelastic scattering signature and set a 90% confidence level upper limit on the WIMP-proton spin-dependent, inelastic scattering cross section of 1.2×10-37 cm2 at the WIMP mass 500 GeV/c2.
Department of Physics and Wright Laboratory, Yale University, New Haven, 06520, CT, United States; Physics Institute, University of São Paulo, São Paulo, 05508-090, Brazil; Center for Underground Physics, Institute for Basic Science (IBS), Daejeon, 34126, 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, Wisconsin IceCube Particle Astrophysics Center, University of Wisconsin-Madison, Madison, 53706, WI, United States; Department of Physics, Kyungpook National University, Daegu, 41566, South Korea; Department of Physics, Sejong University, Seoul, 05006, South Korea; Korea Research Institute of Standards and Science, Daejeon, 34113, South Korea; Department of Accelerator Science, Korea University, Sejong, 30019, 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, Sungkyunkwan University, Suwon, 16419, South Korea; 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