We succeeded in extracting intrinsic momentum profiles of positrons $\left(e^{+}\right)$, parapositronium ($p$-Ps), and orthopositronium ($o$-Ps) in polymers. Unexpectedly, the $e^{+}$ profiles extend beyond $30\times {10}^{-3}{m}_{0}c$ and cannot be approximated by either a single Gaussian or the sum of Gaussians, implying that different electron states contribute to the momentum distributions. The $e^{+}$ profiles are narrower in the order of carbon-, oxygen-, and fluorine-containing polymer groups ($\mathrm{C}$, $\mathrm{O}$, and $\mathrm{F}$ groups). The $p$-Ps profile in the $\mathrm{F}$ group is 1.4 times as broad as those of the $\mathrm{C}$ and $\mathrm{O}$ groups, whereas $o$-Ps profiles are essentially identical in the three polymer groups.

• Received 16 September 2004

DOI:https://doi.org/10.1103/PhysRevB.71.012201