Search for Annual Modulation in Combined ANAIS 112 and COSINE 100 Data using Bayesian Model Comparison

TL;DR

This study uses Bayesian model comparison to analyze combined ANAIS-112 and COSINE-100 data for annual modulation signals, finding no evidence supporting dark matter-induced cosine signals.

Contribution

It introduces a Bayesian approach with different priors to test for annual modulation in combined dark matter detector data, providing a robust statistical framework.

Findings

Bayes factor less than 1.15 indicates no significant modulation evidence

No support for dark matter-induced cosine signals in the data

Analysis codes are publicly available for reproducibility

Abstract

We perform a Bayesian model comparison test between a sinusoidal modulation model and a constant value model using about three years of combined COSINE-100 and ANAIS-112 data. We use both uniform priors and normal priors (based on DAMA best-fit values) for the angular frequency and phase of the cosine signal. We find natural log of Bayes factor for the cosine model comapred to the constant value model to be less than 1.15 for the data in both 1-6 keV and 2-6 keV energy intervals. This shows that there is no evidence for cosine signal from dark matter interactions in the combined ANAIS-112/COSINE-100 data. Our analysis codes have also been made publicly available.