# Search for a Dark Matter-Induced Annual Modulation Signal in NaI(Tl) with the COSINE-100 Experiment

## TL;DR

This study uses 1.7 years of COSINE-100 data to search for dark matter-induced annual modulation signals in NaI(Tl) detectors, aiming to verify the DAMA/LIBRA claim with a model-independent approach.

## Contribution

It provides new constraints on dark matter signals using a large NaI(Tl) dataset, directly testing the DAMA/LIBRA annual modulation claim.

## Key findings

- Background rate of 2.7 cpd/kg/keV in 2-6 keV range
- Best fit modulation amplitude of 0.0092 cpd/kg/keV
- Modulation phase around 127 days

## Abstract

We present new constraints on the dark matter-induced annual modulation signal using 1.7 years, of COSINE-100 data with a total exposure of 97.7 kg$\cdot$years. The COSINE-100 experiment, consisting of 106 kg of NaI(Tl) target material, is designed to carry out a model-independent test of DAMA/LIBRA's claim of WIMP discovery by searching for the same annual modulation signal using the same NaI(Tl) target. The crystal data show a 2.7 cpd/kg/keV background rate on average in the 2--6 keV energy region of interest. Using a $\chi$-squared minimization method we observe best fit values for modulation amplitude and phase of 0.0092$\pm$0.0067 cpd/kg/keV and 127.2$\pm$45 d, respectively.