Universal Soft Terms in the MSSM on D-branes

In Type II string vacua constructed from intersecting/magnetized D-branes, the supersymmetry-breaking soft terms are genericaly non-universal. It is shown that universal supersymmetry-breaking soft terms may arise in a realistic MSSM constructed from intersecting/magnetized D-branes in Type II string theory. For the case of dilaton-dominated supersymmetry-breaking, it is shown that the universal scalar mass and trilinear coupling are fixed such that $m_0=(1/2)m_{3/2}$ and $A_0 = - m_{1/2}$. In addition, soft terms where the universal scalar mass $m_0$ is much larger than the universal gaugino mass $m_{1/2}$ may be easily obtained within the model, corresponding to the Focus Point (FP)/Hyperbolic Branch (HB) regions of the mSUGRA/CMSSM parameter space. Finally, it is shown that the special dilaton and no-scale strict moduli boundary conditions, which are well-known in heterotic string constructions, may also be obtained.Comment: Version published in Nuclear Physics

Learning relationships from theory to design

This paper attempts to bridge the psychological and anthropological views of situated learning by focusing on the concept of a learning relationship, and by exploiting this concept in our framework for the design of learning technology. We employ Wenger's (1998) concept of communities of practice to give emphasis to social identification as a central aspect of learning, which should crucially influence our thinking about the design of learning environments. We describe learning relationships in terms of form (one‐to‐one, one‐to‐many etc.), nature (explorative, formative and comparative), distance (first‐, second‐order), and context, and we describe a first attempt at an empirical approach to their identification and measurement

Financial conditions indexes

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