Related papers: Do particles and anti-particles really annihilate …
Mijnarends et al. [J. Phys. Condens. Matter {\bf 10}, 10383 (1998)] contested the best existing calculations of positron annihilation rates in jellium and crystal lattices, pointing in this way at deficiencies of existing theories of…
We study the inner structure of a positronium confined to a void by treating it as a two-particle quantum system where the electron is captured by an infinite potential well and the positron feels only the Coulomb attraction of the…
Positronium atoms (Ps) are widely used as a probe to characterize voids or vacancies in non-metallic materials, where Ps annihilation lifetime is strongly modified by pickoff, depending on the size of the trapping cavity and on the…
We provide the first counterexample showing that the ground state energy of electrons in an external Coulomb potential is not always a convex function of the number of electrons. This convexity has been conjectured for decades and plays an…
The aim of this work is to identify the mechanisms responsible for very large rates and other peculiarities observed in low-energy positron annihilation on molecules. The two mechanisms considered are: (i) Direct annihilation of the…
We compute the ground state energy of atoms and quantum dots with a large number N of electrons. Both systems are described by a non-relativistic Hamiltonian of electrons in a d-dimensional space. The electrons interact via the Coulomb…
The positron-electron pair annihilation in two photons is known for its numerous applications using PET scanners. The decay of Positronium (Ps) from a standard sealed source in more than two photons is less likely but can be observed with a…
We have calculated all contributions to the energy levels of parapositronium at order $m \alpha^7$ coming from vacuum polarization corrections to processes involving virtual annihilation to two photons. This work is motivated by ongoing…
Recently it has been proposed that the positron, the anti-particle analog of the electron, is capable of forming an anti-matter bond in a composite system of two hydride anions and a positron [Angew. Chem. Int. Ed. 57, 8859 (2018)]. In…
The excited states of a charged particle interacting with the quantized electromagnetic field and an external potential all decay, but such a particle should have a true ground state--one that minimizes the energy and satisfies the…
Most embeddings of the Standard Model into a more unified theory, in particular the ones based on supergravity or superstrings, predict the existence of a hidden sector of particles which have only very weak interactions with the visible…
Recently, we showed that that band as well as line spectra, reveal a left-right symmetry in 4- and 2-fermion systems. We now show how a mass-conjugation explains the difference between atom- and antiatom-states in a stable 2-unit charge…
It is assumed that, in the primordial plasma, at the temperatures above the mass of electron, fermions are in the neutral state being the superposition of particle and antiparticle. There exists neutral proton-electron symmetry.…
The effect of confinement on the self-annihilation rate of positronium is studied in three levels of approximation. Artificial restriction of the electron-positron separation leads to an increase in the annihilation rate over its vacuum…
Calculations of the relaxation energy, contact pair-correlation function, and annihilating-pair momentum density for a single positron immersed in a homogeneous electron gas are presented. We achieve an accurate description of the…
The process of electron positron pair annihilation, driven by strong fields (Inverse Schwinger mechanism) and high-frequency waves, is studied using the Dirac Heisenberg Wigner formalism. In an electron positron plasma, the presence of a…
Recent and ongoing experimental work on the positronium spectrum motivates new efforts to calculate positronium energy levels at the level of three loop corrections. We have obtained results for one set of such corrections involving…
The self-localized quasi-particle excitation of the electron-positron field (EPF) is found for the first time in the framework of a standard form of the quantum electrodynamics. This state is interpreted as the ``physical'' electron…
The non-relativistic energy levels of para-positronium are calculated in the quadrupole approximation of the interaction potential. This approximation technique takes into account the anisotropy of the electrostatic electron-positron…
Recent experimental measurements of the time interval between detection of the two photons emitted in positron/electron annihilation have indicated that collapse of the spatial part of the photon's wavefunction, due to detection of the…