First Direct Search for Light Dark Matter Using the NEON Experiment at a Nuclear Reactor

Autor: Choi, J. J., Ha, C., Jeon, E. J., Kim, J. Y., Kim, K. W., Kim, S. H., Kim, S. K., Kim, Y. D., Ko, Y. J., Koh, B. C., Lee, S. H., Lee, I. S., Lee, H., Lee, H. S., Lee, J. S., Oh, Y. M., Park, B. J.
Rok vydání: 2024
Předmět:
Druh dokumentu: Working Paper
Popis: We report new results from the Neutrino Elastic Scattering Observation with NaI (NEON) experiment in the search for light dark matter (LDM) using 2,636 kg$\cdot$days of NaI(Tl) exposure. The experiment employs an array of NaI(Tl) crystals with a total mass of 16.7 kg, located 23.7 meters away from a 2.8 GW thermal power nuclear reactor. We investigated LDM produced by the $\textit{invisible decay}$ of dark photons generated by high-flux photons during reactor operation. The energy spectra collected during reactor-on and reactor-off periods were compared within the LDM signal region of $1-10$ keV. No signal consistent with LDM interaction with electrons was observed, allowing us to set 90% confidence level exclusion limits for the dark matter-electron scattering cross-section ($\sigma_e$) across dark matter masses ranging from 1 keV/c$^2$ to 1 MeV/c$^2$. Our results set a 90% confidence level upper limit of $\sigma_e = 3.17\times10^{-35}~\mathrm{cm^2}$ for a dark matter mass of 100 keV/c$^2$, marking the best laboratory result in this mass range. Additionally, our search extends the coverage of LDM below 100 keV/c$^2$ first time.
Databáze: arXiv