William S. Marks | Searcharxiv

arXiv2019

Meaningful Details: The value of adding baseline dependence to the Neutrino-Dark Matter Effect

The possible effect on the flavour spectra of astronomical neutrinos from a neutrino-dark matter interaction has been investigated for decoherent neutrinos. In this work, we report results calculated for coherent neutrinos. This was done with two different models for the neutrino dark-matter interactions: a flavour state interaction,as for the weak interaction in the Standard Model, and a mass state interaction, which is predicted by certain non-Standard Models (specifically Scotogenic models). It was found that using a coherent analysis dramatically increased the explorable parameter space for the neutrino-dark matter interaction. However, the detection of coherent astronomical neutrinos presents a significant challenge to experimentalists, because such a detection would require an improvement in energy resolution by at least six orders of magnitude, with similar improvements in astronomical distance determinations.

astro-ph.HE↗

arXiv2018

Extraction of neutrino mixing parameters from experiments with multiple identical detectors

The statistical method used in the analyses of measurements of neutrino oscillation mixing angle $θ_{13}$ by the Daya Bay Collaboration is based on variational minimization of a $χ^2$ function defined in terms of quantities of interest and pull factors which are introduced to deal with effects of systematic uncertainties. For both experiments, the number of parameters that need to be determined is great than the number of available data points (20 vs 6 for the Daya Bay and 12 vs 2 for the RENO). While the results for the mixing angle and the normalization factor were reported, results for the other parameters (pull factors) were omitted in their publications. There exist multiple sets of parameters from the minimization of the $χ^2$ function. We investigate the sensitivity of the extracted mixing angle on this non-uniqueness of minimization results for the Daya Bay data using two methods of minimization. We report results for all parameters, including those of physics interest and pull factors. The obtained results for the mixing angle and the normalization factor are in agreement with those reported by the Daya Bay Collaboration. Furthermore, we present plots of confidence level contours in the space of the mixing angle and normalization factor. We also present results from fittings using a reduced $χ^2$ function with fewer parameters than the one employed by the Daya Bay Collaboration.

hep-ph↗