STUDY DATA FROM V.V. PARAZIAN AND CO-AUTHORS UPDATE KNOWLEDGE OF CONDENSED MATTER

Science Letter
May 19, 2009

"We investigate the angular distribution of positrons in the coherent
process electron-positron pair creation process by high-energy photons
in a periodically deformed single crystal with a complex base,"
researchers in Yerevan, Armenia report (see also Condensed Matter).

"The formula for the corresponding differential cross section is
derived for an arbitrary deformation field. The case is considered
in detail when the photon enters into the crystal at small angles
with respect to a crystallographic axis," wrote V.V. Parazian and
colleagues.

The researchers concluded: "The results of the numerical calculations
are presented for SiO2 and diamond single crystals and Moliere
parameterization of the screened atomic potentials in the case of
the deformation field generated by an acoustic wave of S-type."

Parazian and colleagues published their study in the Journal of
Physics – Condensed Matter (Angular distribution of positrons in
coherent pair production in deformed crystals. Journal of Physics –
Condensed Matter, 2009;21(18):85401).

For additional information, contact V.V. Parazian, Institute Applied
Problems Physics, 25 Nersessian St., Yerevan 0014, Armenia.

Publisher contact information for the Journal of Physics – Condensed
Matter is: IOP Publishing Ltd., Dirac House, Temple Back, Bristol
BS1 6BE, England.