Search for resonances in the electron-positron annihilation-in-flight cross section between 1 and 4 MeV

Autor:	P. Skensved, W. McLatchie, G. C. Ball, T. J. Radcliffe, A. T. Stewart, H. B. Mak, J. R. Leslie, Hal Evans, T. K. Alexander
Rok vydání:	1990
Předmět:	Nuclear reaction Physics Nuclear and High Energy Physics Annihilation Computer Science::Information Retrieval Electron–positron annihilation Hadron Coulomb barrier Electron Nuclear physics Positron Bound state High Energy Physics::Experiment Atomic physics Nuclear Experiment
Zdroj:	Physical Review C. 42:R2275-R2278
ISSN:	1089-490X 0556-2813
Popis:	The observation of narrow, correlated structures in electron and positron spectra from heavy-ion collisions near the Coulomb barrier have prompted speculations that they may be due to the decay of an exotic bound state of the {ital e}{sup +}{ital e}{sup {minus}} system with an invariant mass of between 1.5 and 2.0 MeV. Many experiments have been carried out to detect the effects of such a bound state on the decay of nuclear states and in {ital e}{sup +}{ital e}{sup {minus}} elastic (Bhabha) scattering. We have made a measurement of the annihilation-in-flight cross section of positrons in germanium with energies between 1 and 4 MeV using a tagged-positron'' technique. Our limits on the strength of possible resonances decaying to two {gamma}'s are between 15 and 50 meV. Special attention has been paid in the analysis to the effect of the response function of the detector system on the derived strength limit.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e1c5c1ee19ae5a89a92f1f9c8a87b9b1 https://doi.org/10.1103/physrevc.42.r2275 Zobrazit plný text záznamu