Update on εK\varepsilon_K with lattice QCD inputs

We report updated results for $\varepsilon_K$, the indirect CP violation parameter in neutral kaons, which is evaluated directly from the standard model with lattice QCD inputs. We use lattice QCD inputs to fix $\bar{B}_K$, $|V_{cb}|$, $\xi_0$, $\xi_2$, $|V_{us}|$, and $m_c(m_c)$. Since Lattice 2016, the UTfit group has updated the Wolfenstein parameters in the angle-only-fit method, and the HFLAV group has also updated $|V_{cb}|$. Our results show that the evaluation of $\varepsilon_K$ with exclusive $|V_{cb}|$ (lattice QCD inputs) has $4.0\sigma$ tension with the experimental value, while that with inclusive $|V_{cb}|$ (heavy quark expansion based on OPE and QCD sum rules) shows no tension.Comment: 8 pages, 7 figures, Lattice 2017 proceeding, references update

Type I error and power of the mean and covariance structure confirmatory factor analysis for differential item functioning detection: Methodological issues and resolutions

Recently, mean and covariance structure (MACS) confirmatory factor analysis (CFA) has been widely used to detect items with differential item functioning (DIF). Although how we define the scale does not impact overall model fit or tests for whether or not a given level of measurement equivalence holds, different scaling methods can lead to different conclusions when a researcher locates DIF in a scale. This dissertation evaluates the MACS analysis for DIF detection by means of a Monte Carlo simulation. The simulation results indicate that three statistically equivalent scaling methods provide different outcomes of DIF analysis. In addition, Bonferroni-correction improves the accuracy of the analysis, notably when a scale (or an anchor) is contaminated by DIF. Based on the previous and current simulation studies, this dissertation offers practical guidance for researchers who attempt to evaluate measurement equivalence using CFA

Glassy slowdown and replica-symmetry-breaking instantons

Glass-forming liquids exhibit a dramatic dynamical slowdown as the temperature is lowered. This can be attributed to relaxation proceeding via large structural rearrangements whose characteristic size increases as the system cools. These cooperative rearrangements are well modeled by instantons in a replica effective field theory, with the size of the dominant instanton encoding the liquid's cavity point-to-set correlation length. Varying the parameters of the effective theory corresponds to varying the statistics of the underlying free-energy landscape. We demonstrate that, for a wide range of parameters, replica-symmetry-breaking instantons dominate. The detailed structure of the dominant instanton provides a rich window into point-to-set correlations and glassy dynamics.Comment: 6 pages, 3 figures; v2: narrative revised to clarify our effective-theoretic viewpoint, results unchanged, added reference