Natural and Unnatural Parity Resonance States in the Positron-Hydrogen System with Screened Coulomb Interactions

Ye, Ning; Zhou, Yan; Ho, Yew Kam

doi:10.3390/atoms4010003

Cited by 12 publications

(4 citation statements)

References 52 publications

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“…That is, at a large screening strength the lifetime of the resonance is elongated. This is because of the slower movements of particles in screening environments, which leads to narrowing of the resonance width as a consequence of the uncertainty principle [36,37]. For the second resonance, we note that it first decreases and then increases a little bit.…”

Section: Resultsmentioning

confidence: 86%

Resonances below the ${\rm{Ps}}(n=2)$ excitation threshold of the ${{\rm{e}}}^{+}-{\rm{He}}(1{\rm{s}}2{\rm{s}}{}^{3}{{\rm{S}}}^{{\rm{e}}})$ system interacting with screened potentials

Ghoshal

2017

J. Phys. B: At. Mol. Opt. Phys.

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We have investigated the resonances in the e He S 3 e -+ ( ) system interacting with screened potentials by using the stabilization method. Two types of screened potential have been considered: static screened Coulomb potential and exponential cosine-screened Coulomb potential. A model potential has been used to describe the interaction between the outer electron and the He + ionic core. We have found two resonances below the n Ps 2 He = -+ ( ) threshold. For the unscreened case, our results are in nice agreement with some of the most accurate results available in the literature.

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Section: Resultsmentioning

confidence: 86%

Resonances below the ${\rm{Ps}}(n=2)$ excitation threshold of the ${{\rm{e}}}^{+}-{\rm{He}}(1{\rm{s}}2{\rm{s}}{}^{3}{{\rm{S}}}^{{\rm{e}}})$ system interacting with screened potentials

Ghoshal

2017

J. Phys. B: At. Mol. Opt. Phys.

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“…If the thickness of the barrier diminishes, tunnelling life‐time is lessened leading to the widening of the width, and such phenomenon is termed as the tunnelling effect for shape resonances. [ 51 ] Out of the three above‐mentioned potentials, the repulsive centrifugal barrier is independent of the effect of screening. Static potential and polarization potential are affected by the effect of screening, though, of course, the polarization is a long‐range potential.…”

Section: Resultsmentioning

confidence: 99%

Helium atom embedded in non‐ideal classical plasmas: Doubly excited singlet S states

Das,

Ghoshal,

2024

Contrib. Plasma Phys

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The influence of the non‐ideality (NI) of the classical plasmas on the doubly excited singlet S states of the helium atom (He) embedded in the plasma has been investigated theoretically. A pseudopotential containing the Debye length and the non‐ideality parameter (NIP) as its characteristics is used to represent the screened interaction potentials in the plasma. Using a large wavefunction within the framework of the stabilization method, it has been possible to recognize six doubly excited singlet S states (five lying below the He+(2S) excitation threshold and one lying below the He+(3S) excitation threshold) for the plasma‐free case. The energies and the autoionization life‐times of those states are computed by fitting the density of states to the Lorentzian form. Convergence of the computed results is corroborated by increasing the number of terms in the employed wavefunction. For the plasma‐free case, these results are in excellent agreement with the established results in the literature. A comprehensive analysis has been made on changes induced on those doubly excited states by varying NI over a wide range. It has been observed that the energies of the states gradually approach the corresponding threshold energies with the increasing NI of the plasma, whereas the change in the life‐times (alternatively the widths of the states) of the states shows distinctive features depending on the angular momentum of an individual electron.

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“…CS calculations for pure Coulomb cases on model potentials for a positron-Na system and a positron-K system with some approximations have been reported in the literature [44,45]. CS calculations were carried out on a positron-H system with screened Coulomb potentials, where no model potentials are needed [46][47][48]. However, CS calculations on model potentials in screened Coulomb environments present some challenging problems, and to the best of our knowledge, such calculations have not been reported in the literature.…”

Section: Results Of Present Investigationmentioning

confidence: 99%

An Investigation on the He−(1s2s2 2S) Resonance in Debye Plasmas

Ghoshal

2017

Atoms

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Abstract:The effect of Debye plasma on the 1s2s 2 2 S resonance states in the scattering of electron from helium atom has been investigated within the framework of the stabilization method. The interactions among the charged particles in Debye plasma have been modelled by Debye-Huckel potential. The 1s2s excited state of the helium atom has been treated as consisting of a He + ionic core plus an electron moving around. The interaction between the core and the electron has then been modelled by a model potential. It has been found that the background plasma environment significantly affects the resonance states. To the best of our knowledge, such an investigation of 1s2s 2 2 S resonance states of the electron-helium system embedded in Debye plasma environment is the first reported in the literature.

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Natural and Unnatural Parity Resonance States in the Positron-Hydrogen System with Screened Coulomb Interactions

Cited by 12 publications

References 52 publications

Resonances below the ${\rm{Ps}}(n=2)$ excitation threshold of the ${{\rm{e}}}^{+}-{\rm{He}}(1{\rm{s}}2{\rm{s}}{}^{3}{{\rm{S}}}^{{\rm{e}}})$ system interacting with screened potentials

Resonances below the ${\rm{Ps}}(n=2)$ excitation threshold of the ${{\rm{e}}}^{+}-{\rm{He}}(1{\rm{s}}2{\rm{s}}{}^{3}{{\rm{S}}}^{{\rm{e}}})$ system interacting with screened potentials

Helium atom embedded in non‐ideal classical plasmas: Doubly excited singlet S states

An Investigation on the He−(1s2s2 2S) Resonance in Debye Plasmas

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