Results 21 to 30 of about 2,347 (133)

Collective Electron-Positron Annihilation [PDF]

International Astronomical Union Colloquium, 1992
AbstractThe phenomenon of collective spontaneous annihilation of a magnetized electron-positron plasma is predicted. Like the superradiance in systems with discrete energy spectra, collective annihilation leads to the generation of powerful coherent radiation with the rate of this process considerably exceeding the spontaneous annihilation and ...
A. A. Belyanin, V. V. Kocharovskii, Vl. V. Kocharovskii   +2 more
openaire   +1 more source

On electron-positron annihilation into nucleon-antinucleon pairs [PDF]

New Journal of Physics, 2002
We discuss the puzzling experimental results on baryon-antibaryon production in e+e- annihilation close to the threshold, in particular the fact that sigma(e+e- --> nbar n) >~ sigma(e+e- --> pbar p). We discuss an interpretation in terms of a two-step process, via an intermediate coherent isovector state serving as an intermediary between e+e-
Ellis, John, Karliner, Marek
openaire   +2 more sources

Electron-positron annihilation above charm threshold [PDF]

Physics Letters B, 1975
Abstract A firsr exploratory attempt is made of quantitatively describing in the charm scheme the behaviour of σ (e+e− → hadrons) in the region above charm threshold. Indications are given for the important role of ψ′' and possibly of ψ ‴, second and third radial excitations of ψ.
Barbieri, Riccardo, Kögerler, Reinhart, Kunszt, Z., Gatto, Raoul   +3 more
openaire   +1 more source

Positron annihilation induced Auger electron spectroscopy [PDF]

AIP Conference Proceedings, 1991
A review is given on the results of PAES (positron annihilation induced Auger Electron Spectroscopy) studies to data, with a concentration on those results obtained at the University of Texas at Arlington. Low energy positions, trapped in a surface localized state annihilate with core electrons resulting in the emission of Auger electrons.
openaire   +1 more source

Electron-positron annihilation into hadron-antihadron pairs [PDF]

Physical Review C, 2005
The reactions of electron-positron to nucleon-antinucleon pairs are studied in a non-perturbative quark model. The work suggests that the two-step process, in which the primary quark-antiquark pair forms first a vector meson which in turn decays into a hadron pair, is dominant over the one-step process in which the primary quark-antiquark pair is ...
Y., Yan, P., Suebka, C., Kobdaj, Z.M. Zheng,, Amand, Faessler, V.E. Lyubovitskij, Th. Gutsche   +6 more
openaire   +2 more sources

Ion Concentration and Voltage Imaging With Fluorescent Nanodiamonds

Advanced Materials, EarlyView.
We demonstrate reversible switching between the fluorescent NV0 and the dark NV+ state, in sub‐30 nm FNDs via surface oxidation and hydrogenation, respectively. In an electrochemical cell, we show that the fluorescence from hydrogenated particles enables all‐optical imaging of voltages and ion concentrations at the micrometer scale.
Patrick Voorhoeve, Alessandro Mameli, Hiroshi Abe, Takeshi Ohshima, Qiang Sun, Anita Quigley, Rob Kapsa, Nikolai Dontschuk, Philipp Reineck   +8 more
wiley   +1 more source

Structural and Compositional Effects on the Scintillation Properties of Fast Emitting Metal‐Organic Frameworks

Advanced Science, EarlyView.
The crystalline structure, the atomic numbers of the constituent elementsand the size of MOF crystals each influence their photoluminescence and scintillation properties in distinct ways. Together, these factors provide valuable guidelines for designing systems with optimized performance and tunable timing characteristics, arising from the synergistic ...
Francesca Cova, Jacopo Perego, Biplab Joarder, Nobuhiro Yanai, Anna Vedda, Silvia Bracco, Angiolina Comotti, Angelo Monguzzi, Irene Villa   +8 more
wiley   +1 more source

Electron Interaction and Positron Annihilation in Electron Gases [PDF]

Progress of Theoretical Physics, 1965
An intuitive many-body treatment is presented of the distribution in the total momentum of two gamma rays emitted in annihilation of positrons in a gas of interacting electrons. This treatment results in a momentum distribution of photon pairs which is very close to that of the ideal Fermi distribution of quasi-electrons in the electron gas. This seems
Akira Hatano, Hideo Kanazawa, Yukio Mizuno   +2 more
openaire   +1 more source

Self‐Assembled Telecom Color Centers in Silicon and Their Growth Environment

Advanced Physics Research, EarlyView.
Influence of the growth pressure during the formation of self‐assembled color centers in silicon grown by molecular beam epitaxy at ultra‐low temperatures on the color center's photoluminescence spectral signature. The growth pressure crucially determines color center selectivity, as evidenced by G‐centers, W‐centers, and T‐centers, matrix purity, and ...
Jacqueline Marböck, Enrique Prado Navarrete, Merve Karaman, Oliver E. Lang, S. Mijatovic, Thomas Fromherz, Maciej O. Liedke, Andreas Wagner, Moritz Brehm, Johannes Aberl   +9 more
wiley   +1 more source

Recent Progress of Biomass‐Derived Nitrogen‐Doped Carbon Materials as Electrocatalysts: Carbonization, Functionalization, and Applications

Carbon Energy, EarlyView.
Integrating renewable energy with electrochemical conversion and storage is crucial for sustainable energy solutions. Nitrogen‐doped biomass‐derived carbon materials have emerged as effective catalysts for key reactions such as ORR, HER, and CO2RR. This review explores their synthesis, functionalization, characterization, and catalytic applications ...
Shilong Fu, Haiping Yang, Wiebren de Jong, Ruud Kortlever   +3 more
wiley   +1 more source