Related papers: Positron potential and wavefunction in LaFeAsO
For the bound-muon decay process, the study of atomic effects on the electron spectrum near its endpoint is performed within the framework of the Fermi effective theory. The analysis takes into account for corrections due to…
Microwave, submillimetre-wave, and far-infrared phased arrays are of considerable importance for astronomy. We consider the behaviour imaging phased arrays and interferometric phased arrays from a functional perspective. It is shown that…
PAMELA's observation that the cosmic ray positron fraction increases rapidly with energy implies the presence of primary sources of energetic electron-positron pairs. Of particular interest is the possibility that dark matter annihilations…
Band structure calculations are presented for large supercells of Ba$_2$CuO$_4$ (BCO) with O-vacancies in planar or apic al positions, and of superoxygenated La$_2$CuO$_4$ (LCO) with oxygen interstitials in the La$_2$O$_2$ layers. It is…
We discuss a novel application of matter wave interferometry to characterize the scalar optical polarizability of molecules at 532 nm. The interferometer presented here consists of two material absorptive gratings and one central optical…
The pure lepton decay of the polarized muon is considered, accounting for a new tensor interaction which is outside of the Michel local interactions. This interaction leads to new energy distribution and polarization of the final charged…
A series of experiments measuring high-energy cosmic rays have recently reported strong indications for the existence of an excess of high-energy electrons and positrons. If interpreted in terms of the decay of dark matter particles, the…
This review will deal with several types of free charge localisation in oxides and their consequences on the effective dielectric spectra of such materials. The first one is the polaronic localisation at the unit cell scale on residual…
The electron and positron acceleration in the first cycle of a laser-driven wakefield is investigated. Separatrices between different types of the particle motion (confined, reflected by the wakefield or ponderomotive potential and…
In layered single band systems, the interlayer conductivity depends on the orientation of the in-plane magnetic field and takes maximum values when the magnetic field is perpendicular to flat regions of the Fermi surface. Extending this…
Secondary positrons are produced by spallation of cosmic rays within the interstellar gas. Measurements have been typically expressed in terms of the positron fraction, which exhibits an increase above 10 GeV. Many scenarios have been…
We report high-resolution inelastic x-ray scattering measurements of the acoustic phonons in the single-layer cuprate $Bi_{2}Sr_{2-x)La_{x}CuO_{6+\delta}$. These measurements reveal anomalous broadening of the longitudinal acoustic phonon…
In this paper we consider a general $SU(2)_L\otimes SU(2)_R$ invariant Lagrangian describing scalar, vector and axial-vector resonances. By expanding the WW and the ZZ scattering amplitude up to the fourth order in the external momenta we…
We calculate axion potential in antiferromagnetic insulators from path integral. It is derived from the effective potential for the order parameter of the antiferromagnetic phase in insulators. Static and dynamical axions are defined…
The neutralization probability of low energy Na$^{+}$ ions scattered from In- and As-rich InAs(001) surfaces is measured by time-of-flight spectroscopy. It is found that the neutralization probability for projectiles scattered from As sites…
In this article, we present a deflection measurement setup for Atomic Force Microscopy (AFM). It is based on a quadrature phase differential interferometer: we measure the optical path difference between a laser beam reflecting above the…
A combined experimental and computational methodology for interrogating the phonon contribution to polaron formation in real materials is developed. Using LiF as an example, we show that the recent ab-initio theory of Sio et. al [PRL 122,…
Inelastic neutron scattering measurements demonstrate that the magnetic interactions in antiferromagnetic LaFeAsO are two-dimensional. Spin wave velocities within the Fe layer and the magnitude of the spin gap are similar to the…
We have performed extensive ab initio calculations to investigate phonon dynamics and their possible role in superconductivity in BaFe2As2 and related systems. The calculations are compared to inelastic neutron scattering data that offer…
When a top quark is highly boosted, the $W$ boson from its decay has a substantial linear polarization that results in a $\cos 2\phi$ azimuthal angular correlation among the top decay products. We show that this correlation can be measured…