Magnetic Phase Diagram and Metal-Insulator Transition of NiS2-xSex

Magnetic phase diagram of NiS2-xSex has been reexamined by systematic studies of electrical resistivity, uniform magnetic susceptibility and neutron diffraction using single crystals grown by a chemical transport method. The electrical resistivity and the uniform magnetic susceptibility exhibit the same feature of temperature dependence over a wide Se concentration. A distinct first order metal-insulator (M-I) transition accompanied by a volume change was observed only in the antiferromagnetic ordered phase for 0.50<x<0.59. In this region, the M-I transition makes substantial effects to the thermal evolution of staggered moments. In the paramagnetic phase, the M-I transition becomes broad; both the electrical resistivity and the uniform magnetic susceptibility exhibit a broad maximum around the temperatures on the M-I transition-line extrapolated to the paramagnetic phase.Comment: 6 pages, 8 figures, corrected EPS fil

Study of CP Violating Effects in Time Dependent B0(B0ˉ)→D(∗)∓π±B^0(\bar{B^0}) \to D^{(*)\mp}\pi^{\pm} Decays

We report measurements of time dependent decay rates for $B^0(\bar{B}^0) \to D^{(*)\mp}\pi^{\pm}$ decays and extraction of CP violation parameters containing $\phi_3$. Using fully reconstructed $D^{(*)}\pi$ events from a $140 {\rm fb}^{-1}$ data sample collected at the $\Upsilon(4S)$ resonance, we obtain the CP violation parameters for $D^* \pi$ and $D \pi$ decays, $2R_{D^{(*)} \pi} \sin (2\phi_1 + \phi_3 \pm \delta_{D^{(*)} \pi})$, where $R_{D^{(*)} \pi}$ is the ratio of the magnitudes of the doubly-Cabibbo-suppressed and Cabibbo-favoured amplitudes, and $\delta_{D^{(*)} \pi}$ is the strong phase difference between them. Under the assumption of $\delta_{D^{(*)} \pi}$ being close to either 0 or $180^{\circ}$, we obtain $|2R_{D^* \pi} \sin (2\phi_1 + \phi_3)| = 0.060 \pm 0.040(\mathrm{stat}) \pm 0.019(\mathrm{sys})$ and $|2R_{D \pi} \sin (2\phi_1 + \phi_3)| = 0.061 \pm 0.037(\mathrm{stat}) \pm 0.018(\mathrm{sys})$.Comment: 9 pages, 3 figures, Submitted to Physical Review Letter

Bayesian Inference in Processing Experimental Data: Principles and Basic Applications

This report introduces general ideas and some basic methods of the Bayesian probability theory applied to physics measurements. Our aim is to make the reader familiar, through examples rather than rigorous formalism, with concepts such as: model comparison (including the automatic Ockham's Razor filter provided by the Bayesian approach); parametric inference; quantification of the uncertainty about the value of physical quantities, also taking into account systematic effects; role of marginalization; posterior characterization; predictive distributions; hierarchical modelling and hyperparameters; Gaussian approximation of the posterior and recovery of conventional methods, especially maximum likelihood and chi-square fits under well defined conditions; conjugate priors, transformation invariance and maximum entropy motivated priors; Monte Carlo estimates of expectation, including a short introduction to Markov Chain Monte Carlo methods.Comment: 40 pages, 2 figures, invited paper for Reports on Progress in Physic

Second Language Processing Shows Increased Native-Like Neural Responses after Months of No Exposure

Although learning a second language (L2) as an adult is notoriously difficult, research has shown that adults can indeed attain native language-like brain processing and high proficiency levels. However, it is important to then retain what has been attained, even in the absence of continued exposure to the L2—particularly since periods of minimal or no L2 exposure are common. This event-related potential (ERP) study of an artificial language tested performance and neural processing following a substantial period of no exposure. Adults learned to speak and comprehend the artificial language to high proficiency with either explicit, classroom-like, or implicit, immersion-like training, and then underwent several months of no exposure to the language. Surprisingly, proficiency did not decrease during this delay. Instead, it remained unchanged, and there was an increase in native-like neural processing of syntax, as evidenced by several ERP changes—including earlier, more reliable, and more left-lateralized anterior negativities, and more robust P600s, in response to word-order violations. Moreover, both the explicitly and implicitly trained groups showed increased native-like ERP patterns over the delay, indicating that such changes can hold independently of L2 training type. The results demonstrate that substantial periods with no L2 exposure are not necessarily detrimental. Rather, benefits may ensue from such periods of time even when there is no L2 exposure. Interestingly, both before and after the delay the implicitly trained group showed more native-like processing than the explicitly trained group, indicating that type of training also affects the attainment of native-like processing in the brain. Overall, the findings may be largely explained by a combination of forgetting and consolidation in declarative and procedural memory, on which L2 grammar learning appears to depend. The study has a range of implications, and suggests a research program with potentially important consequences for second language acquisition and related fields

The computation of the geoid model in the state of São Paulo using two methodologies and GOCE models

The purpose of this manuscript is to compute and to evaluate the geoid model in the State of São Paulo from two methodologies (Stokes' integral through the Fast Fourier Transform - FFT and Least Squares Collocation - LSC). Another objective of this study is to verify the potentiality of GOCE-based. A special attention is given to GOCE mission. The theory related to Stokes' integral and Least Squares Collocation is also discussed in this work. The spectral decomposition was employed in the geoid models computation and the long wavelength component was represented by EGM2008 up to degree and order 150 and 360 and GOCE-based models up to 150. The models were compared in terms of geoid height residual and absolute and relative comparisons from GPS/leveling and the results show consistency between them. In addition, a comparison in the mountain regions was carried out to verify the methodologies behavior in this area; the results showed that LSC is less consistent than FFT