Recent results on electron-positron production in heavy ion collisions
The positron and positron-electron line phenomena in heavy ion collisions have been investigated with a new device - APEX - specifically designed for this purpose. Earlier work reporting the observation of line structure in the spectra of positrons and sharp lines in sum-energy spectra of coincident positrons and electrons, produced in low-energy collisions of very heavy nuclei, has provided a persistent puzzle. New data obtained with APEX for {sup 238}U + {sup 181}Ta and {sup 238}U + {sup 232}Th, measured under similar conditions to the previous experiments, do not show evidence for the reported lines. In the specific case of the isolated two-body decay of a neutral object, the cross section limits obtained are far below those implied by the previous results. A measurement of internal pair conversion from a 1.84 MeV transition in {sup 206}Pb was used to verify the correct functioning of APEX.
- OSTI ID:
- 255594
- Report Number(s):
- CONF-9510116--
- Journal Information:
- Bulletin of the American Physical Society, Journal Name: Bulletin of the American Physical Society Journal Issue: 10 Vol. 40; ISSN BAPSA6; ISSN 0003-0503
- Country of Publication:
- United States
- Language:
- English
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