☆ 4.6 Article

Calculation of electron-positron production in supercritical uranium-uranium collisions near the Coulomb barrier

PHYSICAL REVIEW A (2008)

Journal

PHYSICAL REVIEW A

Volume 78, Issue 6, Pages -

Publisher

AMER PHYSICAL SOC

DOI: 10.1103/PhysRevA.78.062711

Keywords

Dirac equation; electron pair production; heavy ion-nucleus reactions; nuclear energy levels; nuclei with mass number 220 or higher; positrons; quantum electrodynamics

Categories

Optics Physics, Atomic, Molecular & Chemical

Funding

NSERC Canada
Shared Hierarchical Academic Research Computing Network (SHARCNET)

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Abstract

The time-dependent Dirac equation was solved for zero-impact-parameter bare U-U collisions in the monopole approximation using a mapped Fourier grid matrix representation. A total of 2048 states including bound, as well as positive- and negative-energy states for an N=1024 spatial grid were propagated to generate occupation amplitudes as a function of internuclear separation. From these amplitudes spectra were calculated for total inclusive positron and electron production, and also the correlated spectra for (e(+),e(-)) pair production. These were analyzed as a function of nuclear sticking time in order to establish signatures of spontaneous pair creation, i.e., QED vacuum decay. Subcritical Fr-Fr and highly supercritical Db-Db collisions both at the Coulomb barrier were also studied and contrasted with the U-U results.

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