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Classical electrodynamics (CED) and quantum electrodynamics (QED) are well
established theories and have been tested experimentally in different
regimes. However, there are still areas of CED and QED that deserve
theoretical and experimental investigation. In view of the increasingly
stronger available laser fields it is becoming feasible to employ them to test
CED and QED under the extreme conditions supplied by ultra-intense fields.
A fundamental problem in CED is the so-called ''radiation reaction'' problem: classically, when a charged particle (an electron, for definiteness) is accelerated by an external field, it emits radiation and this emission changes the motion of the electron. In the realm of CED, the so-called Landau-Lifshitz (LL) describes the motion of an electron by including the effects of radiation reaction [2] and it has not yet been tested experimentally. We explore a new regime of parameters in which, as predicted by the LL equation, the influence of radiation reaction on the electromagnetic spectra emitted by the electron is substantial [2]. What is the quantum analog of radiation reaction? In [3] we have answered this question and we have investigated the quantum radiation dominated regime, in which quantum recoil and radiation reaction effects both dominate the dynamics of the electron. In [4] we have shown that at the quantum level the interaction of the electron with its own electromagnetic field significantly alters the spin dynamics of the electron. We have indicated that an electron initially prepared in a definite spin state will undergo spin-flip while passing through a strong laser field only due to the interaction with its own electromagnetic field and even if it does not radiate photons. We have in addition shown that the classical expression of the electron quasi-momentum is also modified by quantum self-field effects. References [1] L. D. Landau and E. M. Lifshitz, The Classical Theory of Fields, (Elsevier, Oxford, 1975). [2] A. Di Piazza, Lett. Math. Phys. 83, 305 (2008); A. Di Piazza, K. Z. Hatsagortsyan, and C. H. Keitel, Phys. Rev. Lett. 102, 254802 (2009). [3] A. Di Piazza, K. Z. Hatsagortsyan, and C. H. Keitel, Phys. Rev. Lett. 105, 220403 (2010). [4] S. Meuren and A. Di Piazza, Phys. Rev. Lett. (in press). See also arXiv:1107.4531. |
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