Solving the Dirac equation with nonlocal potential by Imaginary Time Step method

The Imaginary Time Step (ITS) method is applied to solve the Dirac equation with the nonlocal potential in coordinate space by the ITS evolution for the corresponding Schr\"odinger-like equation for the upper component. It is demonstrated that the ITS evolution can be equivalently performed for the Schr\"odinger-like equation with or without localization. The latter algorithm is recommended in the application for the reason of simplicity and efficiency. The feasibility and reliability of this algorithm are also illustrated by taking the nucleus $^{16}$O as an example, where the same results as the shooting method for the Dirac equation with localized effective potentials are obtained

Precipitation detector Patent

Precipitation detector and mechanism for stopping and restarting machinery at initiation and cessation of rai

Single and Many Particle Correlation Functions and Uniform Phase Bases for Strongly Correlated Systems

The need for suitable many or infinite fermion correlation functions to describe some low dimensional strongly correlated systems is discussed. This is linked to the need for a correlated basis, in which the ground state may be postive definite, and in which single particle correlations may suffice. A particular trial basis is proposed, and applied to a certain quasi-1D model. The model is a strip of the 2D square lattice wrapped around a cylinder, and is related to the ladder geometries, but with periodic instead of open boundary conditions along the edges. Analysis involves a novel mean-field approach and exact diagonalisation. The model has a paramagnetic region and a Nagaoka ferromagnetic region. The proposed basis is well suited to the model, and single particle correlations in it have power law decay for the paramagnet, where the charge motion is qualitatively hard core bosonic. The mean field also leads to a BCS-type model with single particle long range order.Comment: 23 pages, in plain tex, 12 Postscript figures included. Accepted for publication in J.Physics : Condensed Matte

Engineering handbook on the atmospheric environmental guidelines for use in wind turbine generator development

The guidelines are given in the form of design criteria relative to wind speed, wind shear, turbulence, wind direction, ice and snow loading, and other climatological parameters which include rain, hail, thermal effects, abrasive and corrosive effects, and humidity. This report is a presentation of design criteria in an engineering format which can be directly input to wind turbine generator design computations. Guidelines are also provided for developing specialized wind turbine generators or for designing wind turbine generators which are to be used in a special region of the United States

Evolution of Nuclear Shell Structure due to the Pion Exchange Potential

The evolution of nuclear shell structure is investigated for the first time within density-dependent relativistic Hartree-Fock theory and the role of $\pi$-exchange potential is studied in detail. The energy differences between the neutron orbits \Lrb{\nu1h_{9/2},\nu 1i_{13/2}} in the N=82 isotones and between the proton ones \Lrb{\pi1g_{7/2},\pi1h_{11/2}} in the Z=50 isotopes are extracted as a function of neutron excess $N-Z$. A kink around $Z = 58$ for the N=82 isotones is found as an effect resulting from pion correlations. It is shown that the inclusion of $\pi$-coupling plays a central role to provide realistic isospin dependence of the energy differences. In particular, the tensor part of the $\pi$-coupling has an important effect on the characteristic isospin dependence observed in recent experiments.Comment: 4 pages and 4 figure

Pragmatic View of Short-Baseline Neutrino Oscillations

We present the results of global analyses of short-baseline neutrino oscillation data in 3+1, 3+2 and 3+1+1 neutrino mixing schemes. We show that the data do not allow us to abandon the simplest 3+1 scheme in favor of the more complex 3+2 and 3+1+1 schemes. We present the allowed region in the 3+1 parameter space, which is located at $\Delta{m}^2_{41}$ between 0.82 and 2.19 $\text{eV}^2$ at $3\sigma$. The case of no oscillations is disfavored by about $6\sigma$, which decreases dramatically to about $2\sigma$ if the LSND data are not considered. Hence, new high-precision experiments are needed to check the LSND signal.Comment: 6 pages. Final version published in Phys. Rev. D 88, 073008 (2013

Short-Baseline Electron Neutrino Oscillation Length After Troitsk

We discuss the implications for short-baseline electron neutrino disappearance in the 3+1 mixing scheme of the recent Troitsk bounds on the mixing of a neutrino with mass between 2 and 100 eV. Considering the Troitsk data in combination with the results of short-baseline nu_e and antinu_e disappearance experiments, which include the reactor and Gallium anomalies, we derive a 2 sigma allowed range for the effective neutrino squared-mass difference between 0.85 and 43 eV^2. The upper bound implies that it is likely that oscillations in distance and/or energy can be observed in radioactive source experiments. It is also favorable for the ICARUS@CERN experiment, in which it is likely that oscillations are not washed-out in the near detector. We discuss also the implications for neutrinoless double-beta decay.Comment: 5 pages. Final version published in Phys.Rev. D87 (2013) 01300