New limits for neutrinoless tau decays

Neutrinoless 3-prong tau lepton decays into a charged lepton and either two charged particles or one neutral meson have been searched for using 4.79fb^(-1) of data collected with the CLEO II detector at Cornell Electron Storage Ring. This analysis represents an update of a previous study and the addition of six decay channels. In all channels the numbers of events found are compatible with background estimates and branching fraction upper limits are set for 28 different decay modes. These limits are either more stringent than those set previously or represent the first attempt to find these decays

On Depth, Robustness and Performance Using the Data Re-Uploading Single-Qubit Classifier

Quantum machine learning (QML) is a new field in its’ infancy, promising performance enhancements over many classical machine learning (ML) algorithms. Data reuploading is a QML algorithm with a focus on utilizing the power of a singular qubit as an individually capable classifier. Recently, there have been studies set out to explore the concept of data re-uploading in a classification setting, however, important aspects are often not considered in experiments, which may hinder our understanding of the methodology’s performance. In this work, we conduct an analysis of the single-qubit data re-uploading methodology, in relation to the effect that system depth has on classification performance, and robustness against the influence of environmental noise during training. We do this in an effort to bridge together previous works, solidify the concepts of the methodology, and provide reasonable insight into how transferable the methodology is when applied to non-synthetic data. To further demonstrate the findings, we also analyse results of a case study using a subset of MNIST data. From this work, our experimental results support that an increase in system depth can lead to higher classification performance, as well as improved stability during training in noisy environments, with the sharpest performance improvements seemingly occurring between 1-3 uploading layer repetitions. Leading on from our experimental results, we also suggest areas that for further exploration, to ensure we can maximize classification performance when using the data re-uploading methodology

Corruption, lending and bank performance

This paper uses a sample of 7235 banks from 160 countries between 2000 and 2016 to investigate the link between corruption, lending and bank performance. It considers both country- and bank-level corruption. The study finds that while corruption increases bank lending, it has an adverse impact on bank profits and risks (credit, solvency and distance to default). Corporate lending is found to be most influenced by corruption. Bank-level corruption influences bank performance in both developed and developing countries whereas country-level corruption has a lesser effect on lending in developing countries. The study also finds that greater bank competition, market concentration and improved regulatory environments reduce the effect of corruption on bank lending and performance. Policy makers should focus on enhancing regulatory rules and institutions in order to deal with the adverse impact of corruption on bank performance

The FIRST-Optical-VLA Survey for Lensed Radio Lobes

We present results from a survey for gravitationally lensed radio lobes. Lensed lobes are a potentially richer source of information about galaxy mass distributions than lensed point sources, which have been the exclusive focus of other recent surveys. Our approach is to identify radio lobes in the FIRST catalog and then search optical catalogs for coincident foreground galaxies, which are candidate lensing galaxies. We then obtain higher-resolution images of these targets at both optical and radio wavelengths, and obtain optical spectra for the most promising candidates. We present maps of several radio lobes that are nearly coincident with galaxies. We have not found any new and unambiguous cases of gravitational lensing. One radio lobe in particular, FOV J0743+1553, has two hot spots that could be multiple images produced by a z=0.19 spiral galaxy, but the lensing interpretation is problematic.Comment: 38 pages, 18 figures, aastex, accepted to A

Exclusive and inclusive semileptonic decays of B mesons to D mesons

This is the publisher's version, also available electronically from http://journals.aps.org/prd/abstract/10.1103/PhysRevD.43.651

Electronic branching ratio of the τ lepton

This is the publisher's version, also available electronically from http://journals.aps.org/prd/abstract/10.1103/PhysRevD.45.3976.Using data accumulated by the CLEO I detector operating at the Cornell Electron Storage Ring, we have measured the ratio R=Γ(τ→eν¯(e)ν(τ)) / Γ(1) where Γ(1) is the τ decay rate to final states with one charged particle. We find R=0.2231±0.0044±0.0073 where the first error is statistical and the second is systematic. Together with the measured topological one-charged-particle branching fraction, this yields the branching fraction of the τ lepton to electrons, Be=0.192±0.004±0.006

Efficient Quantum Image Classification Using Single Qubit Encoding

The domain of image classification has been seen to be dominated by high-performing deep learning (DL) architectures. However, the success of this field as seen over the past decade has resulted in the complexity of modern methodologies scaling exponentially, commonly requiring millions of parameters. Quantum computing (QC) is an active area of research aimed towards greatly reducing problems of complexity faced in classical computing. With growing interest towards quantum machine learning (QML) for applications of image classification, many proposed algorithms require usage of numerous qubits. In the noisy intermediate-scale quantum (NISQ) era, these circuits may not always be feasible to execute effectively, therefore we should aim to use each qubit as effectively and efficiently as possible, before adding additional qubits. This paper proposes a new single-qubit based deep quantum neural network for image classification that mimics traditional convolutional neural network techniques, resulting in a reduced number of parameters compared to previous works. Our aim is to prove the concept of the initial proposal by demonstrating classification performance of the single-qubit based architecture, as well as to provide a tested foundation for further development. To demonstrate this, our experiments were conducted using various datasets including MNIST, Fashion-MNIST and ORL face datasets. To further our proposal in the context of the NISQ era, our experiments were intentionally conducted in noisy simulation environments. Initial test results appear promising, with classification accuracies of 94.6, 89.5, and 82.5 achieved on subsets of MNIST, FMNIST and ORL face datasets, respectively. In addition, proposals for further investigation and development were considered, where it is hoped these initial results can be improved

Analysis of hadronic transitions in Υ(3S) decays

This is the publisher's version, also available electronically from http://journals.aps.org/prd/abstract/10.1103/PhysRevD.49.40.Using the CLEO II detector, we have measured the branching fractions for Υ(3S)→ππΥ(1S), Υ(3S)→ππΥ(2S), and the cascade Υ(3S)→Υ(2S)+X, Υ(2S)→π+π−Υ(1S), analyzing the exclusive mode where the daughter Υ state decays to a e(+)e(−) or μ(+)μ(−) pair, as well as the inclusive π(+)π(−) transitions where the final Υ state decays into hadrons. Properties of the ππ system are analyzed. Searches for the cascade decay Υ(3S)→π+π−h(b), h(b)→γη(b) and Υ(3S)→π0h(b) were also performed

Experimental tests of lepton universality in τ decay

This is the publisher's version, also available electronically from http://journals.aps.org/prd/abstract/10.1103/PhysRevD.55.2559.The branching fractions for τ→eνν(τ), μνν(τ), and hν(τ) are measured using data collected with the CLEO detector at the CESR e(+)e(-) collider: Be=0.1776±0.0006±0.0017, Bμ=0.1737±0.0008±0.0018, and B(h)=0.1152±0.0005±0.0012, where the first error is statistical, the second systematic, and h refers to either a charged π or K. Also measured is the τ mass, mτ=(1778.2±1.4) MeV. Lepton universality is affirmed by the relative branching fractions (B(μ)/B(e)=0.9777±0.0063±0.0087, B(h)/B(e)=0.6484±0.0041±0.0060) and the charged-current gauge coupling-constant ratios (g(μ)/g(e)=1.0026±0.0055, g(τ)/g(μ)=0.9990±0.0098). The τ mass result may be recast as a τ neutrino mass limit, m(ν)(τ)<60 MeV at 95% C.L