Complete QED Theory of Multiphoton Trident Pair Production in Strong Laser Fields

Abstract

Electron-positron pair creation by multiphoton absorption in the collision of a relativistic electron with a strong laser beam is calculated within laser-dressed quantum electrodynamics. Total production rates, positron spectra, and relative contributions of different reaction channels are obtained in various interaction regimes. We study the process in a manifestly nonperturbative domain which is shown accessible to future experiments utilizing the electron beam lines at novel x-ray laser facilities or all-optical setups based on laser acceleration. Our theory moreover allows us to add further insights into the experimental data from SLAC [D. Burke, Phys. Rev. Lett. 79, 1626 (1997).].

Analytical model for electromagnetic cascades in rotating electric field

“…[15]. As opposed to [14], the finite pulse durations were allowed, while the laser fields were still treating nonperturbatively in strong-field QED. The individual contributions of the one-step and two-step processes were explicitely identified.…”

“…In Ref. [14] multiphoton trident pair production in strong laser field was studied in a manifestly nonperturbative domain in the periodic plane wave approximation. In addition, the energy spectrum of positrons produced in collision of strong laser pulse with high-energy electron beam was calculated.…”

Analytical solution for the Klein-Gordon equation and action function of the solution for the Dirac equation in counterpropagating laser waves

“…For example, the SLAC E-144 experiment with ξ ≈ 0.3 found a electron-positron-pairproduction rate scaling of R ∼ ξ 10 [2] and in the perturbative theory this would be interpreted as the typical ξ 2N0 dependence with N 0 = 5 photon absorption. However, the calculation [3] reveals that on average more than 6 photons are absorbed in the process, and thus demonstrates the onset of nonperturbative effects on the experiment. It is also found by calculation that if the intensity of the laser field in the above experiment is enhanced that ξ ∼ 1, photon orders up to N ≈ 50 give significant contributions to the total rate and thus the process enters the fully nonperturbative regime.…”

“…By using such laserdressed state the particle-laser interaction has been taken into account to all orders, and the remaining interaction between the laser-dressed particle and the QED vacuum is weak, thus allowing calculations in a perturbative scheme similar to the conventional QED. Various strongfield QED processes in a plane-wave field (or an approximated plane-wave field with the spot radius of the laser beam being much larger than the laser central wavelength [10]) have been investigated by this method, including laser-assisted bremsstrahlung [11], multi-photon Compton scattering [7,12,13], electron-positron pair production [3,14,15] and so on.…”

Electron-positron pair creation induced by quantum-mechanical tunneling

“…The pioneering experiment at SLAC [8] has observed pair-production process triggered from collisions of an electron beam with an intense laser pulse. While this experiment was operated essentially in the perturbation domain, it did observe the onset of nonperturbative signatures [9,10]. Beginning in the 1980's it was attempted to create a supercritical field via two overlapping Coulomb fields associated with colliding heavy ions [11,12].…”