Electron-Positron Pair Creation in Relativistic Heavy-Ion Collisions

3 Electron-Positron Pair Creation in Relativistic Heavy-Ion Collisions 

Basically, one distinguishes between pair creation, where the electron and positron are produced in free (continuum) states and pair creation with an electron in a bound state of one of the ions, for example, in a K-shell state. The latter process is also called bound-free pair production. Pair creation with electron capture into a bound state of the ion changes the charge state of the ion represents one of the major loss processes affecting the stability of ion beams in relativistic heavy-ion colliders. The corresponding cross-section for electron capture is of the order of 100 bam for RHIC energies in U92+(100 GeV/u) -I- U92+(100 GeV/u) collisions and determines the lifetime of ionic charge states in the beam and then the luminosity. 

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