Generalized top-spin analysis and new physics in e+e−e^{+} e^{-} collisions with beam polarization

A generalized top-spin analysis proposed some time ago in the context of Standard Model and subsequently studied in varying contexts is now applied primarily to the case of $e^+e^-\rightarrow t\bar{t}$ with transversely polarized beams. This extends our recent work with new physics couplings of scalar ($S$) and tensor ($T$) types. We carry out a comprehensive analysis assuming only the electron beam to be transversely polarized, which is sufficient to probe these interactions, and also eliminates any azimuthal angular dependence due to standard model or new physics of vector ($V$) and axial-vector ($A$) type interactions. We then consider new physics of general four-Fermi type of $V$ and $A$ type with both beams transversely polarized and discuss implications with longitudinal polarization as well. The generalized spin bases are all investigated in the presence of either longitudinal or transverse beam polarization to look for appreciable deviation from the SM prediction in case of the new physics. 90% confidence level limits are obtained on the interactions for the generalized spin bases with realistic integrated luminosity. In order to achieve this we present a general discussion based on helicity amplitudes and derive a general transformation matrix that enables us to treat the spin basis. We find that beamline basis combined with transverse polarization provides an excellent window of opportunity both for $S$, $T$ and $V$, $A$ new physics, followed by the off diagonal basis. The helicity basis is shown to be the best in case of longitudinal polarization to look for new physics effectsdue to $V$ and $A$.Comment: 21 pages using revtex4-

Grand Challenges of Traceability: The Next Ten Years

In 2007, the software and systems traceability community met at the first Natural Bridge symposium on the Grand Challenges of Traceability to establish and address research goals for achieving effective, trustworthy, and ubiquitous traceability. Ten years later, in 2017, the community came together to evaluate a decade of progress towards achieving these goals. These proceedings document some of that progress. They include a series of short position papers, representing current work in the community organized across four process axes of traceability practice. The sessions covered topics from Trace Strategizing, Trace Link Creation and Evolution, Trace Link Usage, real-world applications of Traceability, and Traceability Datasets and benchmarks. Two breakout groups focused on the importance of creating and sharing traceability datasets within the research community, and discussed challenges related to the adoption of tracing techniques in industrial practice. Members of the research community are engaged in many active, ongoing, and impactful research projects. Our hope is that ten years from now we will be able to look back at a productive decade of research and claim that we have achieved the overarching Grand Challenge of Traceability, which seeks for traceability to be always present, built into the engineering process, and for it to have "effectively disappeared without a trace". We hope that others will see the potential that traceability has for empowering software and systems engineers to develop higher-quality products at increasing levels of complexity and scale, and that they will join the active community of Software and Systems traceability researchers as we move forward into the next decade of research

Top-spin analysis of new scalar and tensor interactions in e^+ e^- collisions with beam polarization

We utilize top polarization in the process e+ e-\rightarrow t\bar{t} at the ILC with transverse beam polarization to probe interactions of the scalar and tensor type beyond the standard model and to disentangle their individual contributions. 90% confidence level limits on the interactions with realistic integrated luminosity are presented and are found to improve by an order of magnitude compared to the case when the spin of the top quark is not measured. Sensitivities of the order of a few times 10^{-3} TeV^{-2} for real and imaginary parts of both scalar and tensor couplings at \sqrt{s}=500 and 800 GeV with an integrated luminosity of 500 fb^{-1} and completely polarized beams is shown to be possible. A powerful model-independent framework for inclusive measurements is employed to describe the spin-momentum correlations and their C, P and T properties is presented in a technical appendix.Comment: 14 pages, 10 figures, uses revtex; replaced with version accepted for publication in Physical Review D; significantly rewritten and reformulated, section added, inclusive section moved to appendix, reference adde

In re Harrods Ltd.: The Brussels Convention and the Proper Application of Forum Non Conveniens to Non-Contracting States

Although the doctrine of forum non conveniens is unknown in Continental legal systems, Community law does not prevent English courts from preserving their discretion to stay proceedings, in conflicts involving a defendant domiciliary, in favor of more appropriate courts in a non-Contracting State. Where the provisions of the Brussels Convention do not address a legal question, the answer must be sought in the objectives and scheme of the Convention. The English Court of Appeals in Harrods properly understood that Community law does not require ritualistic reliance on the Convention\u27s jurisdiction conferring provisions in cases involving a defendant domiciled in a Contracting State and the jurisdiction of a court in a non-Contracting State