Time delay in atomic and molecular collisions and photoionisation/photodetachment

Deshmukh, P. C.; Banerjee, S.

doi:10.1080/0144235x.2021.1838805

Cited by 13 publications

(8 citation statements)

References 122 publications

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“…Since only the final state involves a scattering eigenstate, photoionization can be regarded, in some sense, as a 'half' scattering process. The EWS time delay formalism has been extended to include photoionization and photodetachment by Deshmukh et al [22,23] in a treatment that uses the time-reversal conjugate symmetry between incoming-and outgoing-wave solutions. Apparently contesting that point of view, a recent preprint by Fetić et al [24] asserts that the Wigner time delay cannot be inferred from the liberated particle wavefunction, through its phaseshift, and hence cannot be measured in a photoionization setup.…”

Section: Introductionmentioning

confidence: 99%

Wigner time delay in photoionization: a 1D model study

Elghazawy,

Greene

2023

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

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In scattering theory, the Wigner-Smith time delay, calculated through a phaseshift derivative or its multichannel generalization, has been demonstrated to measure the amount of delay or advance experienced by colliding particles during their interaction with the scattering potential. Fetic, Becker, and Milosevic argue that this concept cannot be extended to include photoionization, viewed as a half-scattering experiment. Their argument is based on the lack of information about scattering phaseshifts in the part of the wavefunction (satisfying the ingoing-wave boundary condition) going to the detector. This article aims to test this claim by examining a photodetachment process in a simple 1D model with a short-range symmetrical potential. Using time-dependent perturbation theory with a dipole interaction, the relevant wavepacket of the outgoing particle is analyzed and compared to the free wavepacket as a reference. Our findings confirm that, indeed, a time delay arises in the liberated fragmentation wavepacket, which is expressed as an energy derivative of the scattering phaseshift. Our study highlights that the source of the phaseshift content in the wavepacket arriving at the detector is the dipole matrix element, which is a direct consequence of imposing the ingoing-wave boundary condition. We illustrate our results through numerical simulations of both the non-free and free wavepackets. The amount of the observed time delay is found to be half of that appearing in a typical scattering experiment.

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Section: Introductionmentioning

confidence: 99%

Wigner time delay in photoionization: a 1D model study

Elghazawy,

Greene

2023

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

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“…In the defining work, the time delay was angle-independent and expressed as the energy derivative of the scattering phase shift [47,48]. Note that the scattering phase shift concerned a particular partial wave and hence was denoted as δ , which is independent of the scattering angle.…”

Section: Introductionmentioning

confidence: 99%

An Investigation of the Resonant and Non-Resonant Angular Time Delay of e-C60 Elastic Scattering

Aiswarya

Jose

2022

Atoms

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Time delay in electron scattering depends on both the scattering angle θ and scattered electron energy E. A study on the angular time delay of e-C60 elastic scattering was carried out in the present work. We employed the annular square well (ASW) potential to simulate the C60 environment. The contribution from different partial waves to the total angular time delay profile was examined in detail. The investigation was performed for both resonant and non-resonant energies, and salient characteristics in the time delay profile for each case were studied.

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“…In particular, Equation (1) serves as the basis for describing the temporal picture of atomic photoionization processes [17][18][19][20][21][22][23][24][25]. Equation (1) in this case needs not to be modified to exclude θ = 0 as the problem of the interference with the unscattered wave does not exist in the case of photoionization.…”

Section: Introductionmentioning

confidence: 99%

“…The time delay (4) at some electron emission angles θ was studied in the series of works on photoionization [19][20][21][22][23][24]. To the best of our knowledge, the angular dependence of the time delay in elastic electron scattering (1) has received no attention so far.…”

Section: Introductionmentioning

confidence: 99%

Time Delay in Electron Collision with a Spherical Target as a Function of the Scattering Angle

Amusia

Baltenkov

Woiciechowski

2021

Atoms

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We have studied the angular time delay in slow-electron elastic scattering by spherical targets as well as the average time delay of electrons in this process. It is demonstrated how the angular time delay is connected to the Eisenbud–Wigner–Smith (EWS) time delay. The specific features of both angular and energy dependencies of these time delays are discussed in detail. The potentialities of the derived general formulas are illustrated by the numerical calculations of the time delays of slow electrons in the potential fields of both absolutely hard-sphere and delta-shell potential well of the same radius. The conducted studies shed more light on the specific features of these time delays.

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Time delay in atomic and molecular collisions and photoionisation/photodetachment

Cited by 13 publications

References 122 publications

Wigner time delay in photoionization: a 1D model study

Wigner time delay in photoionization: a 1D model study

An Investigation of the Resonant and Non-Resonant Angular Time Delay of e-C60 Elastic Scattering

Time Delay in Electron Collision with a Spherical Target as a Function of the Scattering Angle

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