相关论文: Positronium in MOFs: the Atom out of the box
The recent theoretical and experimental activities in positronium (Ps) scattering by atoms and molecules are reviewed with special emphasis at low energies. We critically compare the results of different groups $-$ theoretical and…
Following recent theoretical results, it is suggested that positronium (Ps) might undergo spontaneous oscillations between two 4D spacetime sheets whenever subjected to constant irrotational magnetic vector potentials. We show that these…
We report the results of the analysis of the temperature broadening of the momentum distribution of delocalized Positronium (Ps) in Magnesium Fluoride in terms of optical deformation-potential scattering model (long-wavelength optical…
The scattering of ortho-positronium (Ps) by hydrogen atoms has been investigated in a five-state coupled-channel model allowing for Ps(1s)H(2s,2p) and Ps(2s,2p)H(1s) excitations using a recently proposed electron-exchange model potential.…
The excess energy emitted during the positronium (Ps) formation in condensed matter may be released as light. Spectroscopic analysis of this light can be a new method of studying the electronic properties of materials. We report the first…
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…
When recent experimental positronium (Ps) formation cross sections in noble gases have been compared with the most up-to date theoretical studies, the agreement is qualitative, but not quantitative. In this paper we re-examine this process…
The scattering of ortho positronium (Ps) by H$_2$ has been investigated using a three-Ps-state [Ps(1s,2s,2p)H$_2($X $^1\Sigma_g^+$)] coupled-channel model and using Born approximation for higher excitations and ionization of Ps and B…
The comparison of different models (the Ore, spur and blob models) of positronium (Ps) formation is presented. Because in molecular media Ps is formed in the terminal positron blob and not in an ordinary spur, the application of the blob…
Recent experimental advances in Positronium (Ps) physics have made it possible to produce dense Ps ensembles in which Ps-Ps interactions may occur, leading to the production of Ps$_2$ molecules and paving the way to the realization of a Ps…
The confined variational method in conjunction with the orthogonalizing pseudo-potential method and the stabilization method is used to study the low energy elastic scattering between two spin-polarized metastable positronium…
Bose-Einstein condensates (BECs) of positronium (Ps) have been of experimental and theoretical interest due to their potential application as the gain medium of a $\gamma$-ray laser. Ps BECs are intrinsically spinor due to the presence of…
Producing positronium (Ps) in the metastable $2^3\text{S}$ state is of interest for various applications in fundamental physics. We report here about an experiment in which Ps atoms are produced in this long-lived state by spontaneous…
The low-energy scattering of ortho positronium (Ps) by ortho Ps has been studied in a full quantum mechanical coupled-channel approach. In the singlet channel (total spin $s_T=0$) we find S- and P-wave resonances at 3.35 eV (width 0.02 eV)…
We investigate the modeling of positronium (Ps) states and their pick-off annihilation trapped at open volumes pockets in condensed molecular matter. Our starting point is the interacting many-body system of Ps and a He atom because it is…
Positronium and Muonium are purely leptonic atoms and hence free of an internal sub-structure. This qualifies them as potentially well suited systems to probe the existence of physics beyond the Standard Model. We hence carry out a…
We present the current status for the direct measurement of the positronium hyperfine structure using the $\text{2}^\text{3}\text{S}_\text{1} \rightarrow \text{2}^\text{1}\text{S}_\text{0}$ transition. This experiment, currently being…
The annihilation parameters of positrons with electrons in different shells of Argon, Iron and Copper atoms are calculated below the positronium (Ps) formation thresholds. Quite accurate ab initio calculations of the bound state…
Scattering of positronium (Ps) by helium atom has been investigated in a three-Ps-state coupled-channel model including Ps(1s,2s,2p) states using a recently proposed time-reversal-symmetric regularized electron-exchange model potential.…
We suggest that the observed large annihilation rates of ortho-positronium ($o$-Ps) in halogen gases are due to the process of dissociative Ps attachment, ${\rm Ps} + X_2 \to {\rm Ps}X + X$, where $X$ stands for a halogen atom. This process…