Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

Constraints on WIMP-like dark matter scattering on electrons with COSINE-100

N. Carlin, J. Y. Cho, S. J. Cho, S. Choi, A. C. Ezeribe, L. E. Franca, O. Gileva, C. Ha, I. S. Hahn, S. J. Hollick, E. J. Jeon, H. W. Joo, W. G. Kang, M. Kauer, B. H. Kim, D. Y. Kim, H. J. Kim, J. Kim, K. W. Kim, S. H. Kim, S. K. Kim, W. K. Kim, Y. D. Kim, Y. H. Kim, B. R. Ko, 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, V. H. A. Machado, B. B. Manzato, R. H. Maruyama, S. L. Olsen, H. K. Park, H. S. Park, J. C. Park, J. S. Park, K. S. Park, K. 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, G. H. Yu

TL;DR

This work targets sub-GeV WIMP-like dark matter by searching for WIMP-electron scattering in NaI(Tl) with the COSINE-100 detector. It models both heavy and light vector mediators, incorporates relativistic ionization-factor calculations, and performs a Bayesian spectral fit to 2.82 years of data to derive 90% CL cross-section limits, finding no excess events. The resulting limits are the most stringent for a NaI(Tl) target and exclude DAMA/LIBRA modulation interpretations within this framework, while outlining the COSINE-100U upgrade and a potential modulation analysis to probe even lower energies. The study advances light-DM searches in NaI targets and informs future detector upgrades and analysis strategies for sub-GeV dark matter.

Abstract

We present results of the search for WIMP-like dark matter interaction with electrons in the NaI(Tl) crystals of the COSINE-100 experiment. The two benchmark scenarios of a heavy and a light vector boson as mediator of the interaction were studied. We found no excess events over the expected background in a data-set of 2.82 years, with a total exposure of 172.9 kg-year. The derived 90% confidence level upper limits exclude a WIMP-electron scattering cross section above 6.4 $\times$ 10$^{-33}$ cm$^2$ for a WIMP mass of 0.25 GeV, assuming a light mediator; and above 3.4 $\times$ 10$^{-37}$ cm$^2$ for a 0.4 GeV WIMP, assuming a heavy mediator, and represent the most stringent constraints for a NaI(Tl) target to date. We also briefly discuss a planned analysis using an annual modulation method below the current 0.7 keV threshold of COSINE-100, down to few photoelectrons yield.

Constraints on WIMP-like dark matter scattering on electrons with COSINE-100

TL;DR

This work targets sub-GeV WIMP-like dark matter by searching for WIMP-electron scattering in NaI(Tl) with the COSINE-100 detector. It models both heavy and light vector mediators, incorporates relativistic ionization-factor calculations, and performs a Bayesian spectral fit to 2.82 years of data to derive 90% CL cross-section limits, finding no excess events. The resulting limits are the most stringent for a NaI(Tl) target and exclude DAMA/LIBRA modulation interpretations within this framework, while outlining the COSINE-100U upgrade and a potential modulation analysis to probe even lower energies. The study advances light-DM searches in NaI targets and informs future detector upgrades and analysis strategies for sub-GeV dark matter.

Abstract

We present results of the search for WIMP-like dark matter interaction with electrons in the NaI(Tl) crystals of the COSINE-100 experiment. The two benchmark scenarios of a heavy and a light vector boson as mediator of the interaction were studied. We found no excess events over the expected background in a data-set of 2.82 years, with a total exposure of 172.9 kg-year. The derived 90% confidence level upper limits exclude a WIMP-electron scattering cross section above 6.4 10 cm for a WIMP mass of 0.25 GeV, assuming a light mediator; and above 3.4 10 cm for a 0.4 GeV WIMP, assuming a heavy mediator, and represent the most stringent constraints for a NaI(Tl) target to date. We also briefly discuss a planned analysis using an annual modulation method below the current 0.7 keV threshold of COSINE-100, down to few photoelectrons yield.

Paper Structure

This paper contains 13 sections, 8 equations, 10 figures.

Table of Contents

  1. Introduction
  2. COSINE-100 experiment
  3. DM-electron scattering model
  4. Overview and key expressions for direct detection
  5. Atomic ionization factor
  6. Data analysis
  7. Event selection
  8. COSINE-100 crystals response and WIMP-electron scattering spectra
  9. Background components
  10. Spectral fit
  11. Prospects for COSINE-100 and COSINE-100U
  12. Conclusion
  13. Non-relativistic $f_{ion}$ calculation, and comparison with relativistic model

Figures (10)

  • Figure 1: Illustration of the COSINE-100 experiment. The NaI(Tl) crystals arrange, LS and plastic panels, and passive shields are presented.
  • Figure 2: Feynman diagram that represents the DM-electron scattering, where $V$ is a vector boson and $\chi$ is the WIMP.
  • Figure 3: Computed spectra in NaI considering the non-relativistic and relativistic methods. In the blue curves, $m_\chi=1$ GeV is considered, and in the orange curves, $m_\chi=10$ GeV is considered. Solid lines represent the computation of spectra with the relativistic approach for $f_{ion}$ calculation, while dashed lines represent spectra with the non-relativistic approach for $f_{ion}$ calculation.
  • Figure 4: Expected event rate in COSINE-100 NaI(Tl) detectors considering a heavy mediator and 5 different WIMP masses. The curves represent an average over the 5 analyzed crystals. $\overline{\sigma}_e$ is fixed at $10^{-38}$ cm$^2$.
  • Figure 5: Measured data for the 2.82 years data-set used in this analysis (black points), and the crystals background model in the ROI (red histogram). Data and background for all analyzed crystals are summed. Background components are labeled into 4 groups according to their origin. The yellow and green bands represent the 1$\sigma$ and 2$\sigma$ systematics, which are the dominant sources of uncertainties in the ROI.
  • ...and 5 more figures