Anomalous Annihilation of Positrons in Several Solid Hydrocarbons

Abstract

In previous experiments with positrons annihilating in liquid organic materials (Hogg et al.) the measurements of IN (intensity of the low momentum component from angular correlation data) and I2 (intensity of the long lived component from lifetime measurements) have resulted in IN = I2/3 within experimental error.For samples of CH4, C6H6, and C6H12 measurements in the liquid state yield the expected equality between IN and I2/3. However, in the solid state for these substances there is a marked disagreement between IN and I2/3. The value of IN, in all cases, is essentially zero suggesting that no positronium is formed, but the value of I2 remains large.