Related papers: Positron Binding and Annihilation in Alkane Molecu…
Para positronium composed by an electron-antielectron pair is an unstable system decaying into two high energetic gamma photons via self annihilation process, due to the conservation of the charge conjugation parity in electromagnetically…
The AMS-02 collaboration has recently presented measurements of excellent quality of the cosmic electron and positron fluxes as well as the positron fraction. We use the measurements of the positron flux to derive, for the first time,…
We employ effective mass theory for degenerate hole-bands to calculate the acceptor binding energies for Be, Mg, Zn, Ca, C and Si substitutional acceptors in GaN and AlN. The calculations are performed through the 6$\times $6…
We investigate one-photon annihilation of the electron-positron pair in the field of a central, very heavy and positively charged atomic nucleus. The explicit formula for the annihilation rate of this process $\Gamma^{(b)}_{1 \gamma}$ is…
The many-body system comprising a He nucleus, three electrons, and a positron has been studied using the exact diagonalization technique. The purpose has been to clarify to which extent the system can be considered as a distinguishable…
The exact solution of a diffusion$-$reaction model for the trapping and annihilation of positrons at interfaces of precipitate$-$matrix composites is presented considering both cylindrical or spherical precipitates. Diffusion-limitation is…
Several first-principles calculations of positron-annihilation characteristics in solids have added gradient corrections to the local-density approximation within the theory by Arponen and Pajanne [Ann. Phys. (N.Y.) 121, 343 (1979)] since…
Computational studies have shown that one or more positrons can stabilize two repelling atomic anions through the formation of two-center positronic bonds. In the present work, we study the energetic stability of a system containing two…
The two-photon positron annihilation density matrix is found to separate into a diagonal center of energy factor implying maximally entangled momenta, and a relative factor describing decay. For unknown positron injection time, the…
We report a computational first-principles study of positron trapping at vacancy defects in metals and semiconductors. The main emphasis is on the energetics of the trapping process including the interplay between the positron state and the…
We determined the dominant polaron recombination loss mechanism in pristine and annealed polythiophene:fullerene blend solar cells by applying the photo-induced charge extraction by linearly increasing voltage (photo-CELIV) method in…
An enhanced binding of an $N$-particle system interacting through a scalar bose field is investigated, where $N\geq 2$. It is not assumed that this system has a ground state for a zero coupling. It is shown, however, that there exists a…
Positron and electron cosmic rays provide a complementary way to study the galactic environment. The actual cosmic rays experiments, for instance PAMELA and HEAT, have presented very exciting results in this field. The observed positron…
A method is proposed to manipulate the annihilation dynamics of a dense gas of positronium atoms employing superradiance and subradiance regimes of the cooperative spontaneous emission of the system. The annihilation dynamics is controlled…
We study a class of exactly solvable models for strongly correlated electrons, defined on a set of N cells, and with infinite on-site repulsion on part of the sites of each cell. For 2N or more electrons the exact ground state is known. We…
The bound and resonance states along with corresponding autoionization widths for nitrogen sulphide (NS) molecule are determined using electron NS$^+$ cation scattering calculations. The calculations are performed for $^2{\Sigma}^+$,…
We performed fully self-consistent calculations of $\bar{p}$-nuclear bound states using a complex ${\bar p}$-nucleus potential accounting for $\bar{p}$-atom data. While the real part of the potential is constructed within the relativistic…
The possibility of channeling the low-energy relativistic positrons around separate crystallographic axes with coaxial symmetry of negative ions in some types of crystals is shown. The process of annihilation of positrons with electrons of…
Supported by results obtained with semi-classical quantization techniques, and with a quantum mechanical "square-root Klein-Gordon" operator, it is argued that Positronium (Ps) may exhibit a proper quantum-mechanical ground state whose…
The n,p-networks model is used to estimate binding energies and radii of proton-rich (N < Z) nuclei. These calculations have been made for some representative examples of even-Z and odd-Z nuclei with nucleon numbers lower than sixty. Good…