Magnon scattering processes and low temperature resistivity in CMR manganites

Low temperature resistivity of CMR manganites is investigated. At the ground state, conduction electrons are perfectly spin polarized, which is called half-metallic. From one-magnon scattering processes, it is discussed that the resistivity of a half metal as a function of temperature scales as rho(T) - rho(0) propto T^3. We take (Nd,Tb,Sr)MnO_3 as an example to compare theory and experiments. The result is in a good agreement.Comment: To appear in Proc. ICM 200

Tokyo Axion Helioscope

A new search result of the Tokyo axion helioscope is presented. The axion helioscope consists of a dedicated cryogen-free 4T superconducting magnet with an effective length of 2.3 m and PIN photodiodes as x-ray detectors. Solar axions, if exist, would be converted into X-ray photons through the inverse Primakoff process in the magnetic field. Conversion is coherently enhanced even for massive axions by filling the conversion region with helium gas. The present third phase measurement sets a new limit of g_{a\gamma\gamma}<(5.6--13.4)\times10^{-10} GeV^{-1} for the axion mass of 0.84<m_a<1.0 eV at 95% confidence level.Comment: 4th Patras Workshop on Axions, WIMPs and WISP

Generalized Arcsine Law and Stable Law in an Infinite Measure Dynamical System

Limit theorems for the time average of some observation functions in an infinite measure dynamical system are studied. It is known that intermittent phenomena, such as the Rayleigh-Benard convection and Belousov-Zhabotinsky reaction, are described by infinite measure dynamical systems.We show that the time average of the observation function which is not the $L^1(m)$ function, whose average with respect to the invariant measure $m$ is finite, converges to the generalized arcsine distribution. This result leads to the novel view that the correlation function is intrinsically random and does not decay. Moreover, it is also numerically shown that the time average of the observation function converges to the stable distribution when the observation function has the infinite mean.Comment: 8 pages, 8 figure

Preliminary Clinical Evaluation: The What, Where, How Approach to Scoring

The SCoR is driving for preliminary clinical evaluation (PCE) however; currently there is no method of quantification to assess quality. FRCR has an approach to quantify comments in the rapid reporting examination (CR2B).The aim of this project was to develop a robust scoring system that enables comprehensive image evaluation regardless of profession. An image test bank was administered using RadBench with equal prevalence of normal /abnormal. A random sample of attempts was selected to pilot the scoring model. Sensitivity, specificity and accuracy were calculated. A scoring system (WWH) was developed based on the WHAT (fracture type), WHERE (location), HOW (displacement/angulation) concept (Harcus & Wright 2014) to evaluate the PCE. The results were compared to those obtained using the FRCR model. Calculated actual mean accuracy, sensitivity and specificity scores were 87%, 80% and 93% respectively. FRCR scores were 88%, 80% and 97%. WWH scores were 65%, 37%, and 93%. The FRCR score appears to mirror the actual decision scores however it does not reflect the fact that the PCE for abnormal cases is often incomplete; 'What' 67%, 'Where' 87%, 'How' 7%. The PCE score should ideally correlate with the actual score in order to provide useful information to the referring clinician. Whilst most comments state the location, less states the type, and very few refer to angulation or displacement. Analysis of the PCE is a useful indicator for targeting professional development

Observation of strong electron dephasing in disordered Cu93_{93}Ge4_4Au3_3 thin films

We report the observation of strong electron dephasing in a series of disordered Cu$_{93}$Ge$_4$Au$_3$ thin films. A very short electron dephasing time possessing very weak temperature dependence around 6 K, followed by an upturn with further decrease in temperature below 4 K, is found. The upturn is progressively more pronounced in more disordered samples. Moreover, a ln$T$ dependent, but high-magnetic-field-insensitive, resistance rise persisting from above 10 K down to 30 mK is observed in the films. These results suggest a nonmagnetic dephasing process which is stronger than any known mechanism and may originate from the coupling of conduction electrons to dynamic defects.Comment: to appear in Phys. Rev. Let