Spontaneous violation of CP symmetry in the strong interactions

Some time ago Dashen pointed out that spontaneous CP violation can occur in the strong interactions. I show how a simple effective Lagrangian exposes the remarkably large domain of quark mass parameters for which this occurs. I close with some warnings for lattice simulations.Comment: 10 pages, 1 figure; final version to appear in PR

Leading for Change: Measuring the Characteristics of K-12 Principals in New Mexico

Research has established an indirect influence between school principals and student achievement on standardized tests. This paper considers how to measure the relationships between teacher and principal perceptions of four dimensions of principal leadership in New Mexicos K-12 schools—setting a shared vision, developing a culture of learning, managing resources, and collaborating with the community—and student scaled score growth over four years on New Mexico\u27s standards-based assessments. Using two valid, reliable survey instruments, data was electronically collected from 437 teachers and 41 principals; aggregate reading and math scaled scores were also collected for all students in these 41 schools. Based on one-way analysis of variance (ANOVA) and estimates of Cronbach\u27s alpha, in this application, both instruments used to survey teachers and principals were confirmed as valid and reliable. Additionally, the two instruments appeared to provide similar information from principals and teachers, as three pairs of teacher and principal variables had statistically significant correlations. Two statistically significant relationships were identified relevant to the potential use of scaled score growth to measure school, principal, and teacher performance. First, schools with lower scaled scores in 2008 averaged more growth than schools with higher schools. Second, scaled score growth appeared to have a leveling effect, as no statistically significant correlations were observed between scaled score growth and student or school demographic variables such as percentage of English learners, student ethnicity, percentage of students with disabilities, or percentage of students qualifying for free or reduced price lunches.\u2

Emergent gauge dynamics of highly frustrated magnets

Condensed matter exhibits a wide variety of exotic emergent phenomena such as the fractional quantum Hall effect and the low temperature cooperative behavior of highly frustrated magnets. I consider the classical Hamiltonian dynamics of spins of the latter phenomena using a method introduced by Dirac in the 1950s by assuming they are constrained to their lowest energy configurations as a simplifying measure. Focusing on the kagome antiferromagnet as an example, I find it is a gauge system with topological dynamics and non-locally connected edge states for certain open boundary conditions similar to doubled Chern-Simons electrodynamics expected of a $Z_2$ spin liquid. These dynamics are also similar to electrons in the fractional quantum Hall effect. The classical theory presented here is a first step towards a controlled semi-classical description of the spin liquid phases of many pyrochlore and kagome antiferromagnets and towards a description of the low energy classical dynamics of the corresponding unconstrained Heisenberg models.Comment: Updated with some appendices moved to the main body of the paper and some additional improvements. 21 pages, 5 figure

Containerless synthesis of interesting glasses

One aspect of containerless glass experimentation was thoroughly examined: glass forming ability. It is argued that although containerless processing will abet glass formation, other ground-based methods can do the job better. However, these methods have limitations, such as sample dimensions and concomitant ability to make property measurements. Most importantly, perhaps, is the observation that glass properties are a function of preparation procedure. Thus, it seems as though there still is an argument for use of containerless processing for glass forming