Influence of NaI background and mass on testing the DAMA modulation

TL;DR

This study evaluates how NaI detector background levels and mass influence the ability to test the DAMA dark matter signal, emphasizing the importance of low-background detectors like SABRE for conclusive results.

Contribution

The paper provides sensitivity analysis for NaI detectors testing DAMA, comparing predicted limits with existing experiments, and highlights the impact of background reduction on detection confidence.

Findings

Lower background improves detection sensitivity.

SABRE can exclude or discover DAMA signal within 2 years.

Method accurately reproduces previous exclusion limits.

Abstract

We present here the model dependent and independent sensitivity studies for NaI detectors designed to test the DAMA result, and compare the predicted limits from SABRE with the present performance of both ANAIS and COSINE. We find that the strongest discovery and exclusion limits are set by a detector with the lowest background (assuming equal run times), and also note that our method correctly computes the present exclusion limits previously published by ANAIS and COSINE. In particular, with a target mass of 50 kg and background rate of 0.36 cpd/kg/keV (after veto), SABRE will be able to exclude the DAMA signal with 3$\sigma$ confidence or `discover' it with 5$\sigma$ confidence within 2 years. This strongly motivates the quest for ever lower backgrounds in NaI detectors.