arXiv subjects

Aisha Dantuluri

Publications and source records attributed to Aisha Dantuluri.

2 recordsLinked to original sources

arXiv2020

Robust model comparison tests of DAMA/LIBRA annual modulation

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 $Δχ^2$ 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.

astro-ph.CO↗

arXiv2018

Do tau lepton branching fractions obey Benford's law?

According to Benford's law, the most significant digit in many datasets is not uniformly distributed, but obeys a well defined power law distribution with smaller digits appearing more often. Among one of the myriad particle physics datasets available, we find that the leading decimal digit for the $τ$ lepton branching fraction shows marginal disagreement with the logarithmic behavior expected from the Benford distribution. We quantify the deviation from Benford's law using a $χ^2$ function valid for binomial data, and obtain a $χ^2$ value of 16.9 for nine degrees of freedom, which gives a $p$-value of about 5%, corresponding to a 1.6$σ$ disagreement. We also checked that the disagreement persists under scaling the branching fractions, as well as by redoing the analysis in a numerical system with a base different from 10. Among all the digits, `9' shows the largest discrepancy with an excess of $4σ$. This discrepancy is because the digit `9' is repeated for three distinct groups of correlated modes, with each group having a frequency of two or three, leading to double-counting. If we count each group of correlated modes only once, the discrepancy for this digit also disappears and we get pristine agreement with Benford distribution.

physics.soc-ph↗