Universal noise and Efimov physics

Probability distributions for correlation functions of particles interacting via random-valued fields are discussed as a novel tool for determining the spectrum of a theory. In particular, this method is used to determine the energies of universal N-body clusters tied to Efimov trimers, for even N, by investigating the distribution of a correlation function of two particles at unitarity. Using numerical evidence that this distribution is log-normal, an analytical prediction for the N-dependence of the N-body binding energies is made.Comment: 6 pages, 3 figures. Invited contribution to the 21st International Conference on Few-Body Problems in Physics (FB21

Baryon properties in meson mediums from lattice QCD

We present results for the ground-state mass shifts of octet baryons due to the presence of a medium of pions or kaons from a lattice QCD calculation performed at a single value of the quark mass, corresponding to a pion mass of $m_\pi$ ~ 390 MeV, and a spatial volume V ~ (4fm)^3. We use a canonical approach in which correlators are formed using a single baryon propagator and a fixed number of meson propagators, up to n=9. From the ground-state energies we calculate two- and three-body interaction parameters. We also extract combinations of low-energy constants by comparing our results to tree level chiral perturbation theory at non-zero isospin/kaon chemical potential.Comment: 7 pages, 3 figures, Proceedings of the 31st International Symposium on Lattice Field Theory (Lattice 2013), July 29 - August 3, 2013, Mainz, German

Lattice methods for strongly interacting many-body systems

Lattice field theory methods, usually associated with non-perturbative studies of quantum chromodynamics, are becoming increasingly common in the calculation of ground-state and thermal properties of strongly interacting non-relativistic few- and many-body systems, blurring the interfaces between condensed matter, atomic and low-energy nuclear physics. While some of these techniques have been in use in the area of condensed matter physics for a long time, others, such as hybrid Monte Carlo and improved effective actions, have only recently found their way across areas. With this topical review, we aim to provide a modest overview and a status update on a few notable recent developments. For the sake of brevity we focus on zero-temperature, non-relativistic problems. After a short introduction, we lay out some general considerations and proceed to discuss sampling algorithms, observables, and systematic effects. We show selected results on ground- and excited-state properties of fermions in the limit of unitarity. The appendix contains details on group theory on the lattice.Comment: 64 pages, 32 figures; topical review for J. Phys. G; replaced with published versio

An Assessment Comparing Community College Students’ Computer Self-Efficacy and Task Based Computer Knowledge

This quantitative research study explored the relationship between students perceived computer self-efficacy and actual knowledge of computer related skills in computer hardware/technology, windows, Word, Excel, and PowerPoint and whether gender, race, and education level affected the research findings. The participants in this study were students enrolled in an introductory computer concepts course at a community college located in the southeastern region of the United States. The computer course was a required for all students to receive an Associate of Arts and Associate of Applied Science degree. Data was collected in traditional face-to-face class sections and consisted of a pre- and post-computer self-efficacy survey and a pre- and post-test skills assessment on three different campuses. The scores in the area of computer hardware/technology, windows, Word, Excel, and Power Point were compared to determine whether a relationship exists between Computer self-efficacy and actual knowledge in the area of computers. In addition to a series of a one-way Analysis of Variance, a Repeated Measures Analysis of Variance and a Bivariate Correlation, the study also utilized descriptive analysis of demographic data and responses to a questionnaire regarding participant’s prior technology experience and usage. Findings of the study indicated that students’ computer self-efficacy was much greater than actual knowledge in the area of computers. Findings of the study did show no significant difference in computer self-efficacy concerning gender, race, and education. No significant differences were found in the education level and skill level of the participants at the beginning of the CSC 1113 course. A significant difference was found in skill level among the different races at the beginning of the CSC 1113 course with the exception of Power Point. The study did show that there was no significant difference in skill level for gender except in the area of technology. The study found a positive correlation in the numbers of computer courses students completed in high school to computer self-efficacy at the beginning of the semester in the course CSC 1113. At the completion of the course CSC 1113, Computer Concepts, computer self-efficacy scores were significantly higher. Findings also showed a significant increase in the skill levels, Windows, Word, Excel, and Power Point at the completion of the CSC 1113 course. The study had not shown significant difference in hardware/technology skills at the completion of the CSC 1113 course

N-body Efimov states from two-particle noise

The ground state energies of universal N-body clusters tied to Efimov trimers, for N even, are shown to be encapsulated in the statistical distribution of two particles interacting with a background auxiliary field at large Euclidean time when the interaction is tuned to the unitary point. Numerical evidence that this distribution is log-normal is presented, allowing one to predict the ground-state energies of the N-body system.Comment: Extended discussion of results; published versio