Multiphoton Ionization of Metastable Hydrogen Atom by Electron and Positron Impact

Sinha, Chittaranjan; Biswas, Akash; Deb, Sanjoy

doi:10.1088/1742-6596/388/11/112006

Cited by 1 publication

(1 citation statement)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In particular, the ionization processes have been widely investigated in the literature by several authors [7][8][9]. Regarding the theoretical situation, low energy positron-impact ionization of hydrogen atom in the presence of a laser field has often been discussed in several articles [10][11][12][13][14]. Most of these studies have formulated explicit expressions for the laser-assisted triple differential cross-sections (TDCS) by assuming a weak laser electric field compared with the characteristic inter-atomic field and a laser frequency much lower than any of the transition frequencies of the hydrogen atom.…”

Section: Introductionmentioning

confidence: 99%

Laser-Assisted Positron-Impact Ionization of Hydrogen Atoms

et al. 2019

View full text Add to dashboard Cite

The theory of triple differential cross-sections, developed previously within the framework of nonrelativistic Schrödinger formalism, is extended to the relativistic treatment by using the Dirac-Volkov formalism. At high energies, the colliding particles lose their Coulomb character and the channel of the symmetric coplanar geometry is opened. In the first Born approximation, we have studied theoretically the laser-assisted relativistic ionization of hydrogen atoms by positron impact in this geometry. Triple differential cross-sections are calculated by using two approaches: (i) RPWSG to describe relativistic plane wave in the symmetric geometry, (ii) DVPWSG (Dirac-Volkov plane wave in the symmetric geometry) in which we take full account of the relativistic dressing effects, has been proposed to study the influence of laser field on the colliding particles. To check the consistency of our model, we have used, for comparison, the nonrelativistic approach: nonrelativistic plane wave in the symmetric geometry. Numerical results for the variation of relativistic triple differential cross-sections and their dependences on laser field parameters (intensity, frequency) and incident positron energy are also presented. As for the laser modifications, by summing over a very large number of exchanged photons, the laser-assisted triple differential cross-sections usually tends to approach the laser-free triple differential cross-sections, obeying the famous Kroll-Watson sum rule for positron projectile. In the absence, of any experimental data at high energies for this particular ionization process, we are not in a position to compare the present results with the experimental findings.

show abstract