Polarized hyperon production in single-inclusive electron-positron annihilation at next-to-leading order

We study the production of polarized $\Lambda$-hyperons in electron-positron annihilation. We are particularly interested in the transverse-spin dependence of the cross section for unpolarized incident electron-positron pairs. At high energies this process may be described in the collinear twist-3 framework, where the hadronization transition of partons into a transversely polarized $\Lambda$-hyperon can be written in terms of collinear twist-3 fragmentation matrix elements. We calculate the hard partonic cross sections and interference terms in perturbative QCD to next-to-leading order accuracy. We find that the QCD equation of motion plays a crucial role in our analysis. As a byproduct, assuming the validity of QCD factorization for twist-3 observables at next-to-leading order, we derive the evolution equation for the relevant twist-3 fragmentation matrix element.Comment: 43 pages, 25 figure

Patterns for building dependable systems with trusted bases

We propose a set of patterns for structuring a system to be dependable by design. The key idea is to localize the system's most critical requirements into small, reliable parts called trusted bases. We describe two instances of trusted bases: (1) the end-to-end check, which localizes the correctness checking of a computation to end points of a system, and (2) the trusted kernel, which ensures the safety of a set of resources with a small core of a system.Northrop Grumman Cybersecurity Research ConsortiumNational Science Foundation (U.S.) (Deep and Scalable Analysis of Software Grant 0541183)National Science Foundation (U.S.) (CRI: CRD - Development of Alloy Technology and Materials Grant 0707612