# Strong field atomic ionization: Origin of high-energy structures in photoelectron spectra

 Title Strong field atomic ionization: Origin of high-energy structures in photoelectron spectra Publication Type Journal Article Year of Publication 2003 Wassaf, J, Veniard, V, Taieb, R, Maquet, A Journal PHYSICAL REVIEW LETTERS Volume 90 Issue 1 Date Published JAN 10 ISSN 0031-9007 Keywords paper Abstract Two distinct interpretations have been proposed to account for conspicuous enhancements of the ionization peaks in the high energy part of above-threshold ionization spectra. One of them ascribes the enhancement to a multiphoton resonance involving an excited state, while other analysis performed for zero-range model potential link it to channel closings,  i.e., to the change in the number of photons needed to ionize the atom when the laser intensity increases. We report the results of model calculations that confirm the existence of a resonant process in atoms and shed light on why short-range potential models can mimic the experimental observations. DOI 10.1103/PhysRevLett.90.013003 Full Text