Thermalization of positronium in decay rate measurements
A precision measurement of the orthopositronium (o-Ps) decay rate, performed in gases, disagrees with the QED theoretical prediction by 9{sigma}. The thermalization of o-Ps is an important systematic concern for such experiments since incompletely thermalized Ps could have an age-dependent collisional quenching rate with the gas molecules. An experiment is underway to directly measure the o-Ps thermalization rate using the same apparatus and gases. The doppler broadening of 2{gamma} annihilation radiation from magnetically quenched o-Ps is used to deduce the average energy as a function of its age. This experiment will also address the issue of positronium thermalization in a recent parapositronium decay rate measurement, also performed in gases.
- OSTI ID:
- 394198
- Report Number(s):
- CONF-9605105--; CNN: Grant PHY-9417854
- Journal Information:
- Bulletin of the American Physical Society, Journal Name: Bulletin of the American Physical Society Journal Issue: 3 Vol. 41; ISSN BAPSA6; ISSN 0003-0503
- Country of Publication:
- United States
- Language:
- English
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