English

Robust model comparison tests of DAMA/LIBRA annual modulation

Cosmology and Nongalactic Astrophysics 2020-02-11 v2 Instrumentation and Methods for Astrophysics High Energy Physics - Experiment

Abstract

We evaluate the statistical significance of the DAMA/LIBRA claims for annual modulation using three independent model comparison techniques, viz frequentist, information theory, and Bayesian analysis. We fit the data from the DAMA/LIBRA experiment to both cosine and a constant model, and carry out model comparison by choosing the constant model as the null hypothesis. For the frequentist test, we invoke Wilk's theorem and calculate the significance using Δχ2\Delta \chi^2 between the two models. For information theoretical tests, we calculate the difference in Akaike Information Criterion (AIC) and Bayesian Information criterion (BIC) between the two models. We also compare the two models in a Bayesian context by calculating the Bayes factor. We also search for higher harmonics in the DAMA/LIBRA data using generalized Lomb-Scargle periodogram. We finally test the sensitivity of these model comparison techniques in discriminating between pure noise and a cosine signal using synthetic data. This is the first proof of principles application of AIC, BIC as well as Bayes factor to the DAMA data. All our analysis codes along with the data used in this work have been made publicly available.

Cite

@article{arxiv.1906.05726,
  title  = {Robust model comparison tests of DAMA/LIBRA annual modulation},
  author = {Aditi Krishak and Aisha Dantuluri and Shantanu Desai},
  journal= {arXiv preprint arXiv:1906.05726},
  year   = {2020}
}

Comments

13 pages, 2 figures. Additional sections on searches for higher harmonics and sensitivity of model comparison tests used here in distinguishing real signals from noise with synthetic data

R2 v1 2026-06-23T09:52:51.153Z