The β\beta angle as the CP violating phase in the CKM matrix

The CKM matrix describing quark mixing with three generations can be parameterized by three Euler mixing angles and one CP violating phase. In most of the parameterizations, the CP violating phase chosen is not a directly measurable quantity and is parametrization dependent. In this work, we propose to use the most accurately measured CP violating angle $\beta$ in the unitarity triangleas the phase in the CKM matrix, and construct an explicit $\beta$ parameterization. We also derive an approximate Wolfenstein-like expression for this parameterization.Comment: RevTex 7 pages with one figure. Version to be published in Phys. Lett. B. arXiv admin note: substantial text overlap with arXiv:1204.123

The α\alpha, β\beta and γ\gamma parameterizations of CP violating CKM phase

The CKM matrix describing quark mixing with three generations can be parameterized by three mixing angles and one CP violating phase. In most of the parameterizations, the CP violating phase chosen is not a directly measurable quantity and is parametrization dependent. In this work, we propose to use experimentally measurable CP violating quantities, $\alpha$, $\beta$ or $\gamma$ in the unitarity triangle as the phase in the CKM matrix, and construct explicit $\alpha$, $\beta$ and $\gamma$ parameterizations. Approximate Wolfenstein-like expressions are also suggested.Comment: 14 page, 1 figur

Examining Stakeholder Perspectives: Process, Performance and Progress of the Age-Friendly Taiwan Program.

Since Taiwans age-friendly city (AFC) program was launched in 2012, the central government has provided various resources to the countrys 22 local authorities, including budgetary support, policy advocacy, and consultation from a team of experts. This study examines stakeholder perspectives on the process, performance, and outcome of the AFC program. A 53-item questionnaire was developed based on the World Health Organization (WHO) guideline, including mechanisms and processes (20 items), outcome evaluations (23 items), and resource integration (10 items). There was a great difference found among scores between facilitators and experts for inter-exchange experience with local and international cities (40%) and monitor and revise indicators (37%) in mechanisms and processes, evaluate performance of indicators and action plans (37%) in outcome evaluations, and interaction between government and community (46%) and interaction between civil organization and senior society (39%) in resource integration. Clearly, facilitators showed overly optimistic assessments in AFC mechanisms and processes, outcome evaluation, and resource integration. The results showed disconnect between experts expectations versus actual practice conducted by facilitators. Implications of these findings are to integrate top down expectations with the realities of bottom up practice to design more realistic evaluations; continue to educate stakeholders about design, implementation and evaluation; and further integrate resources from government, civil organizations, and community

Magnetic Interaction between Surface Engineered Rare-earth Atomic Spins

We report the ab initio study of rare-earth adatoms (Gd) on an insulating surface. This surface is of interest because of previous studies by scanning tunneling microscopy showing spin excitations of transition metal adatoms. The present work is the first study of rare-earth spin-coupled adatoms, as well as the geometry effect of spin coupling, and the underlying mechanism of ferromagnetic coupling. The exchange coupling between Gd atoms on the surface is calculated to be antiferromagnetic in a linear geometry and ferromagnetic in a diagonal geometry, by considering their collinear spins and using the PBE+U exchange correlation. We also find the Gd dimers in these two geometries are similar to the nearest-neighbor (NN) and the next-NN Gd atoms in GdN bulk. We analyze how much direct exchange, superexchange, and RKKY interactions contribute to the exchange coupling for both geometries by additional first-principles calculations of related model systems