Le 23 octobre 2015De 10h30 à 12h00
Antonino Di Piazza
Max-Planck-Institut fur Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany
Classical electrodynamics (CED) and quantum electrodynamics (QED) are well established physical theories and their predictions have been conrmed experimentally in various regimes and with extremely high accuracy. However, there are still areas of CED and of QED that deserve theoretical and experimental investigation, especially when physical processes occur in the presence of strong background electromagnetic elds, i.e., of the order of the so-called \critical” eld of QED [1]. In the presence of electromagnetic elds of such a high strength even the vacuum becomes unstable and electron-positron pair production spontaneously occurs. In view of the increasingly stronger available laser elds it is becoming feasible to employ them to test CED and QED under the extreme conditions supplied by intense elds [1].
After a broad introduction on CED and QED, I describe dierent regimes of laser-matter interaction at ultra-high laser intensities and introduce present and upcoming experimental eorts to test the two theories under such extreme conditions. As a prominent theoretical example of open problems which can be addressed also experimentally, I focus on the so-called \radiation reaction” problem both classically [2] and quantum mechanically [3]. Finally, I describe recent experimental results on the laser-based generation of high-energy, collimated positron [4] and electron-positron [5] beams and their relevance for astrophysics.
[1] A. Di Piazza, C. Muller, K. Z. Hatsagortsyan, and C. H. Keitel, Rev. Mod. Phys. 84, 1177 (2012).
[2] A. Di Piazza, K. Z. Hatsagortsyan, and C. H. Keitel, Phys. Rev. Lett. 102, 254802 (2009); M. Tamburini
et al., New J. Phys. 12, 123005 (2010).
[3] A. Di Piazza, K. Z. Hatsagortsyan, and C. H. Keitel, Phys. Rev. Lett. 105, 220403 (2010); F. Mackenroth
and A. Di Piazza, Phys. Rev. Lett. 110, 070402 (2013); N. Neitz and A. Di Piazza, Phys. Rev. Lett.
111, 054802 (2013).
[4] G. Sarri, W. Schumaker, A. Di Piazza, M. Vargas, B. Dromey, M. E. Dieckmann, V. Chvykov, A.
Maksimchuk, V. Yanovsky, Z. H. He, B. X. Hou, J. A. Nees, A. G. R. Thomas, C. H. Keitel, M. Zepf,
and K. Krushelnick, Phys. Rev. Lett. 110, 255002 (2013).
[5] G. Sarri, K. Poder, J. M. Cole, W. Schumaker, A. Di Piazza, B. Reville, T. Dzelzainis, D. Doria, L. A.
Gizzi, G. Grittani, S. Kar, C. H. Keitel, K. Krushelnick, S. Kuschel, S. P. D. Mangles, Z. Najmudin, N.
Shukla, L. O. Silva, D. Symes, A. G. R. Thomas, M. Vargas, J. Vieira, and M. Zepf, Nature Commun.
6, 6747 (2015).