Recent Progress in Double Beta Decay

At least one neutrino has a mass of about 50 meV or larger. However, the absolute mass scale for the neutrino remains unknown. Studies of double beta decay offer hope for determining the absolute mass scale. Furthermore, the critical question: Is the neutrino its own antiparticle? is unanswered. In particular, zero-neutrino double beta decay can address the issues of lepton number conservation, the particle-antiparticle nature of the neutrino, and its mass. A summary of the recent progress in double beta decay, and the related technologies will be discussed in the context of the future double beta decay program.Comment: Invited submission to Mod. Phys. Lett.

Double Beta Decay

The motivation, present status, and future plans of the search for the neutrinoless double beta decay are reviewed. It is argued that, motivated by the recent observations of neutrino oscillations, there is a reasonable hope that neutrinoless double beta decay corresponding to the neutrino mass scale suggested by oscillations, of about 50 meV, actually exists. The challenges to achieve the sensitivity corresponding to this mass scale, and plans to overcome them, are described.Comment: 34 pages, 3 figures included, Submitted to Annu. Rev. Nucl. Part. Sci., vol.5

Ge Detectors and 0νββ0\nu\beta\beta: The Search for Double Beta Decay with Germanium Detectors: Past, Present and Future

High Purity Germanium Detectors have excellent energy resolution; the best among the technologies used in double beta decay. Since neutrino-less double beta decay hinges on the search for a rare peak upon a background continuum, this strength has enabled the technology to consistently provide leading results. The Ge crystals at the heart of these experiments are very pure; they have no measurable U or Th contamination. The added efforts to reduce the background associated with electronics, cryogenic cooling, and shielding have been very successful, leading to the longevity of productivity. The first experiment published in 1967 by the Milan group of Fiorini, established the benchmark half-life limit $>3\times10^{20}$ yr. More recently, the \MJ\ and GERDA collaborations have developed new detector technologies that optimize the pulse waveform analysis. As a result, the GERDA collaboration refuted the claim of observation with a revolutionary approach to shielding by immersing the detectors directly in radio-pure liquid argon. In 2018, the \MJ\ collaboration, using a classic vacuum cryostat and high-Z shielding, achieved a background level near that of GERDA by developing very pure materials for use nearby the detectors. Together, GERDA and \MJ\ have provided limits approaching $10^{26}$ yr. In this article, we elaborate on the historical use of Ge detectors for double beta decay addressing the strengths and weaknesses. We also summarize the status and future as many \MJ\ and GERDA collaborators have joined with scientists from other efforts to give birth to the LEGEND collaboration. LEGEND will exploit the best features of both experiments to extend the half-life limit beyond $10^{28}$ yr with a ton-scale experiment.Comment: Invited submission to Frontiers in Physic

A comparative analysis of two different analysers used for determination of the Total Organic Carbon in pharmaceutical grade water

Total Organic Carbon (TOC) is a routine test for pharmaceutical grade water. Several manufacturers supply equipment of different designs but there is a dearth of published, peer-reviewed, information evaluating the various analysers. In this study, we compared two TOC analysers, both validated to the same pharmacopoeial criteria, but with different oxidation and detection methods. The results in this paper show that there were no unexplained out-of-specification results and that both analysers operated equivalently in terms of the pharmacopoeial 500ppb pass/fail limits. However, significant differences between the TOC levels reported from paired samples were observed, two paired samples recorded a pass/fail conflict (albeit flagged with an overestimation warning), as well as differences in analyser responses between spiked samples that contained low levels of nitro- and chloro-carbon compounds

Comparative analysis of TOC and conductivity analysers as applied to pharmaceutical water analysis

Pharmaceutical grade water requires the measurement of bioburden, Total Organic Carbon and conductivity. Here we report a comparative analysis from two TOC analysers and two conductivity systems. The TOC analysers showed significantly different results

Detection of benzimidazole carbamates and amino metabolites in liver by surface plasmon resonance-biosensor

This research was funded by the Irish Department of Agriculture, Fisheries and Food under the Food Institutional Research Measure as part of the National Development Plan (Project 05/R&D/TN/355)peer-reviewedTwo surface plasmon resonance (SPR) biosensor screening assays were developed and validated to detect 11 benzimidazole carbamate (BZT) and four amino-benzimidazole veterinary drug residues in liver tissue. The assays used polyclonal antibodies, raised in sheep, to detect BZTs and amino-benzimidazoles. A modified Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) extraction method was developed to isolate benzimidazole carbamate residues. Liver samples were extracted using an acetonitrile extraction method. BZTs were purified by dispersive solid phase extraction (d-SPE) using C18 sorbent. Residues of amino-benzimidazoles were effectively cleaned-up using a simple cyclohexane defatting step. The assays were validated in accordance with the performance criteria described in 2002/657/EC. The BZT assay limit of detection was calculated to be 32 μg kg−1, the detection capability (CCβ) was determined to be 50 μg kg−1 and the mean recovery of analytes was in the range 77–132%. The amino-benzimidazole assay limit of detection was determined to be 41 μg kg−1, the CCβ was determined to be 75 μg kg−1 and analyte recovery was in the range 103–116%. Biosensor assay performance was tested by analysing liver tissue from animals treated with benzimidazole drugs and comparing the results with an ultra high performance liquid chromatography tandem mass spectrometry (UHPLC–MS/MS) confirmatory method. All non-compliant samples were identified using the biosensor assays.Department of Agriculture, Food and the Marin