arXiv subjects

Steven D. Biller

Publications and source records attributed to Steven D. Biller.

6 recordsLinked to original sources

arXiv2022

Slow-Fluor Scintillator for Low Energy Solar Neutrinos and Neutrinoless Double Beta Decay

The potential for using slow-fluor liquid scintillators to study low energy solar neutrinos and neutrinoless double beta decay (0nbb) is explored through a series of simulations. The fluorescence model assumed for the primary fluor has characteristics similar to acenaphthene, recently used to demonstrate Cherenkov separation at energies around 1 MeV. Results here indicate notably better directional reconstruction in large-scale detectors than has previously been suggested by other approaches, allowing better identification of low energy solar neutrinos. These studies indicate that a detector with as little as ~30% coverage using currently available photomultiplier tubes could be able to make a measurement of the CNO solar neutrino flux to a precision of better than 10% (enough to distinguish metallicity models) with a few kiloton-years of exposure. In terms of 0nbb studies here suggest that the ability to separate mechanisms based on angular distributions is weak, but that the rejection of solar neutrino backgrounds with such a technique might potentially approach a factor of 10 for endpoint energies near 2.5 MeV in the angular hemisphere defined by the solar direction.

physics.ins-det↗

arXiv2022

An Alternative Design for Large Scale Liquid Scintillator Detectors

The construction of large-scale liquid scintillator detectors is complicated by the need to separate the scintillation region from photomultiplier tubes (PMTs) due to their intrinsic radioactivity. This is generally done using acrylic or nylon barriers, whose own activity can also lead to substantial reduction of the fiducial detection volume for a number of low energy (MeV) studies, and whose construction becomes increasingly difficult and expensive for larger detector volumes. Here we present an initial simulation study of an alternative geometric construction known as SLIPS (Stratified LIquid Plane Scintillator), which aims to avoid such physical barriers entirely by instead using layers of lipophobic liquids to separate PMTs from the scintillation region.

physics.ins-det↗

arXiv2021

Combined Constraints on Majorana Masses from Neutrinoless Double Beta Decay Experiments

Combined bounds on the Majorana neutrino mass for light and heavy neutrino exchange mechanisms are derived from current neutrinoless double beta decay (0ν\b{eta}\b{eta}) search results for a variety of nuclear matrix element (NME) models. The approach requires self-consistency of a given model to predict NMEs across different isotopes. The derived bounds are notably stronger than those from any single experiment and show less model-to-model variation, highlighting the advantages of using multiple isotopes in such searches. Projections indicate that the combination of near-term experiments should be able to probe well into the inverted mass hierarchy region. A method to visually represent 0ν\b{eta}\b{eta} experimental results is also suggested to more transparently compare across different isotopes and explicitly track model dependencies.

hep-ex↗

arXiv2020

Slow Fluors for Effective Separation of Cherenkov Light in Liquid Scintillators

The timing and spectral characteristics of four highly efficient, slow fluors are presented for liquid scintillator solutions using linear alkylbenzene (LAB) as the primary solvent. The mixtures exhibit high light yields, but with rise times of several ns or more and decay times on the order of tens of ns. Consequently, such liquid scintillator mixtures can be used for effective separation of Cherenkov and scintillation components based on timing in large scale liquid scintillation detectors. Such a separation, showing high light yield and directional information, is demonstrated here on a bench-top scale for electrons with energies extending below 1 MeV. This could have significant consequences for the future development of such detectors for measurements of solar neutrinos and neutrinoless double beta decay as well as providing good directional information for elastic scattering events from supernovae neutrinos and reactor anti-neutrinos, amongst others.

physics.ins-det↗

arXiv2019

Multi-site Event Discrimination in Large Liquid Scintillation Detectors

Simulation studies have been carried out to explore the ability to discriminate between single-site and multi-site energy depositions in large scale liquid scintillation detectors. A robust approach has been found that is predicted to lead to a significant statistical separation for a large variety of event classes, providing a powerful tool to discriminate against backgrounds and break important degeneracies in signal extraction. This has particularly relevant implications for liquid scintillator searches for neutrinoless double beta decay ($0νββ$) from $^{130}$Te and $^{136}$Xe, where it is possible for a true $0νββ$ signal to be distinguished from most radioactive backgrounds (including those from cosmogenic production) as well as unknown gamma lines from the target isotope.

physics.ins-det↗

arXiv2015

Another Look at Confidence Intervals: Proposal for a More Relevant and Transparent Approach

The behaviors of various confidence/credible interval constructions are explored, particularly in the region of low statistics where methods diverge most. We highlight a number of challenges, such as the treatment of nuisance parameters, and common misconceptions associated with such constructions. An informal survey of the literature suggests that confidence intervals are not always defined in relevant ways and are too often misinterpreted and/or misapplied. This can lead to seemingly paradoxical behaviours and flawed comparisons regarding the relevance of experimental results. We therefore conclude that there is a need for a more pragmatic strategy which recognizes that, while it is critical to objectively convey the information content of the data, there is also a strong desire to derive bounds on models and a natural instinct to interpret things this way. Accordingly, we attempt to put aside philosophical biases in favor of a practical view to propose a more transparent and self-consistent approach that better addresses these issues.

physics.data-an↗