STRONG SUPPRESSION OF COULOMB CORRECTIONS TO THE e⁺e^- PAIR PRODUCTION CROSS SECTION IN ULTRARELATIVISTIC NUCLEAR COLLISIONS
Lee R.N., Milstein A.I.

Received: August 6, 2009

PACS: 25.75.Dw, 12.20.-m, 25.20.Lj, 34.90.+q

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The Coulomb corrections to the e⁺e^- pair production cross section in ultrarelativistic nuclear collisions are calculated in the next-to-leading approximation with respect to the parameter , where γ_A,B are the Lorentz factors of colliding nuclei. We find considerable reduction of the Coulomb corrections even for large γ_Aγ_B due to the suppression of the e⁺e^- pair production with the total energy of the order of a few electron masses in the rest frame of one of the nuclei. Our result explains why the deviation from the Born result was not observed in the SPS experiment [Vane1994,Vane1997].