Search for electron-positron pair production by non-relativistic heavy charged particles

Coulomb distortion effects in electron positron pair production near threshold

“…Discrepancies between experimental results [2,3] and the calculation of Heitler and Nordheim appeared. For this reason we had repeated the calculation [5].…”

“…In order to analyze the reasons for this disagreement we included non perturbative effects (i.e. Coulomb distortion of initial and final state wave functions) into our previous calculation with special regard to the projectile energy and the charge of target and projectile in the experiments mentioned [2,3] (Ta(p,p'e+e-), Ekin<l.8MeV; W(p,p' e+ e-), Eki n < 2.5 MeV).…”

Electron-positron pair production by collisions of non-relativistic charged particles

“…The result for the amplitude conforms with that given in Eq. (100.8) of [6], but differs from the result of [1], which has been used in the calculation of the integrated cross-section in [2,3]. The result of [lJ is obtained from Eq.…”

“…For this reason we have redone the calculation. We noticed that Heitler and Nordheim in their approximation neglected a contribution which turns out to be important and which has been neglected also in previous calculations [- [2][3][4][5] of the cross-section, although the correct formula -at least for the differential cross-section -is given in the book of Landau and Lifschitz [-6]. Recently positron emission in heavy ion collisions has been the subject of much experimental and theoretical work.…”

“…During the last 25 years the interest in such processes has been renewed. Both, experimental [2,3] and theoretical work [-4, 5] has been performed on the pair production by collisions of protons or c~-particles on heavy nuclei. Some discrepancies between experiments and the calculation of Heitler and Nordheim appeared.…”