Three-year annual modulation search with COSINE-100
Prabal Adhikari, E. Barbosa de Souza, N. Carlin, J. J. Choi, Su Bin Choi, A. C. Ezeribe, L. E. França, C. Ha, I. S. Hahn, Sophia J. Hollick, E. J. Jeon, J. H. Jo, H. W. Joo, W. G. Kang, M. Kauer, 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, H. J. Kwon, 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, D. S. Leonard, B. B. Manzato, R. Maruyama, R. J. Neal, B. J. Park, H. Park, H. S. Park, K. S. Park, S. D. Park, R. L. C. Pitta, H. Prihtiadi, Siddharth Jaya Sajeevan J, C. Rott, K. A. Shin, A. Scarff, N.J.C. Spooner, W. G. Thompson, L. Yang, G. H. Yu
Abstract
COSINE-100 is a direct detection dark matter experiment that aims to test DAMA/LIBRA's claim of dark matter discovery by searching for a dark-matter-induced annual modulation signal with NaI(Tl) detectors. We present new constraints on the annual modulation signal from a dataset with a 2.82 yr livetime utilizing an active mass of 61.3 kg for a total exposure of $173\text{ }\text{ }\mathrm{kg}\ifmmode\cdot\else\textperiodcentered\fi{}\mathrm{yr}$. This new result features an improved event selection that allows for both lowering the energy threshold to 1 keV and a more precise time-dependent background model. In the 1--6 and 2--6 keV energy intervals, we observe best-fit values for the modulation amplitude of $0.0067\ifmmode\pm\else\textpm\fi{}0.0042$ and $0.0051\ifmmode\pm\else\textpm\fi{}0.0047\text{ }\text{ }\mathrm{counts}/(\mathrm{day}\ifmmode\cdot\else\textperiodcentered\fi{}\mathrm{kg}\ifmmode\cdot\else\textperiodcentered\fi{}\mathrm{keV})$, respectively, with a phase fixed at 152.5 days.