Low Energy Tests of the Weak Interaction

The study of low energy weak interactions of light quarks and leptons continues to provide important insights into both the Standard Model as well as the physics that may lie beyond it. We review the status and future prospects for low energy electroweak physics. Recent important experimental and theoretical developments are discussed and open theoretical issues are highlighted. Particular attention is paid to neutrino physics, searches for permanent electric dipole moments, neutral current tests of the running of the weak mixing angle, weak decays, and muon physics. We argue that the broad range of such studies provides an important complement to high energy collider searches for physics beyond the Standard Model. The use of low energy weak interactions to probe novel aspects of hadron structure is also discussed.Comment: 82 pages, 6 figures: published version (with some additional references and a typographical error fixed

Charged Current Universality and the MSSM

We analyze the prospective impact of supersymmetric radiative corrections on tests of charged current universality involving light quarks and leptons. Working within the R-parity conserving Minimal Supersymmetric Standard Model, we compute the corresponding one-loop corrections that enter the extraction of the Cabibbo-Kobayashi-Maskawa matrix element $V_{ud}$ from a comparison of the muon-decay Fermi constant with the vector coupling constant determined from nuclear and neutron $\beta$-decay. We also revisit earlier studies of the corrections to the ratio $R_{e/\mu}$ of pion leptonic decay rates $\Gamma[\pi^+ \to e^+ \nu (\gamma)]$ and $\Gamma[\pi^+ \to \mu^+ \nu (\gamma)]$. In both cases, we observe that the magnitude of the corrections can be on the order of $10^{-3}$. We show that a comparison of the first row CKM unitarity tests with measurements of $R_{e/\mu}$ can provide unique probes of the spectrum of first generation squarks and first and second generation sleptons.Comment: 38 pages, 17 figure

Decision model to design a blockchain-based system for storing sensitive health data

The storage and sharing of sensitive health data in Blockchain-based systems implicates data protection issues that must be addressed when designing such systems. Those issues can be traced back to the properties of decentralized systems. A blessing but also a curse in the context of health data is the transparency of the Blockchain, because it allows the stored data to be viewed by all participants of the network. In addition, the property of immutability is in contrast to the possibility to delete the personal data upon request according to the European General Data Protection Regulation (GDPR). Accordingly, approaches to tackle these issues have recently been discussed in research and industry, e.g. by storing sensitive data encrypted On-Chain or Off-Chain on own servers connected to a Blockchain. These approaches deal with how the confidentiality and integrity of stored data can be guaranteed and how data can be deleted. By reviewing the proposed approaches, we develop a taxonomy to summarize their specific technical characteristics and create a decision model that will allow the selection of a suitable approach for the design of future Blockchain-based systems for the storage of sensitive health data. Afterwards, we demonstrate the utility of the decision model based on a use case for storing test results from a digital dementia screening application. The paper concludes with a discussion of the results and suggestions for future research

Precision Probes of a Leptophobic Z' Boson

Extensions of the Standard Model that contain leptophobic Z' gauge bosons are theoretically interesting but difficult to probe directly in high-energy hadron colliders. However, precision measurements of Standard Model neutral current processes can provide powerful indirect tests. We demonstrate that parity-violating deep inelastic scattering of polarized electrons off of deuterium offer a unique probe leptophobic Z' bosons with axial quark couplings and masses above 100 GeV. In addition to covering a wide range of previously uncharted parameter space, planned measurements of the deep inelastic parity-violating eD asymmetry would be capable of testing leptophobic Z' scenarios proposed to explain the CDF W plus di-jet anomaly.Comment: 5 page, 1 figur

Weak mixing angle at low energies

We determine the weak mixing angle in the MS-bar scheme at energy scales relevant for present and future low energy electroweak measurements. We relate the renormalization group evolution of the weak mixing angle to the corresponding evolution of the QED coupling and include higher-order terms in alpha_s and alpha that had not been treated in previous analyses. We also up-date the analysis of non-perturbative hadronic contributions and argue that the associated uncertainty is small compared to anticipated experimental errors. The resulting value of the low-energy weak mixing angle is sin^2 theta_W (0) = 0.23867 +- 0.00016.Comment: 21 pages; 1 figure and some references added, some changes in text; final version as publishe