Physical Sciences and Mathematics | Open Access Articles

Large Contribution Of Virtual Delbrück Scattering To The Emission Of Photons By Relativistic Nuclei In Nucleus-Nucleus And Electron-Nucleus Collisions, Ilya F. Ginzburg, Ulrich D. Jentschura, Valery G. Serbo

Physics Faculty Research & Creative Works

Delbrück scattering is the elastic scattering of a photon in the Coulomb field of a nucleus via a virtual electron loop. The contribution of this virtual subprocess to the emission of a photon in the collision of ultra-relativistic nuclei, Z₁Z₂→Z₁Z ₂γ, is considered. We identify the incoming virtual photon as being generated by one of the relativistic nuclei involved in the binary collision and the scattered photon as being emitted in the process. The energy and angular distributions of the photons are calculated. The discussed process has no infrared divergence. The total cross …

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Investigating Many-Electron Exchange Effects In Electron-Heavy-Atom Scattering, S. Bellm, J. Lower, Z. Stegen, Don H. Madison, H. P. Saha

Physics Faculty Research & Creative Works

In a recent publication we presented measurements and distorted-wave Born approximation (DWBA) calculations for spin asymmetries resulting from the scattering of 148 eV spin-polarized electrons from ground-state xenon atoms. While achieving reasonably good agreement between theory and experiment by accounting for many-body exchange effects through a local exchange potential, sizable discrepancies remained in some cases. It was proposed that a more sophisticated treatment of exchange might be the key to obtaining better agreement. Here we present high-precision experimental results at a lower projectile-electron energy of 112 eV. Due to improvements made to our spectrometer, these data are of significantly-improved statistical …

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The Decomposition Of Yba₂Cu₃O₇₋Δ Doped Into Ba₂Yruo₆, H. A. Blackstead, William B. Yelon, M. Kornecki, M. P. Smylie, P. J. Mcginn, Jinbo Yang, Qingsheng Cai, William Joseph James

Physics Faculty Research & Creative Works

One of the persistent criticisms of claims for observation of superconductivity in Ba2YRu1−uCuuO6 (O6) is that the diamagnetism is actually due to the decomposition of the material into YBa2Cu3O7−delta and other phases. We report a series of experiments in which YBa2Cu3O7−delta is doped into Ba2YRuO6 and carried through a series of sintering steps which were followed by magnetization, neutron diffraction, and scanning electron microscopy/microprobe measurements. It was found that the dopant YBa2Cu3O7−delta decomposed and failed to reform with cooling. It is concluded that the O6 phase is the stable high-temperature phase. The Cu released from the Y123 decomposition doped the …

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Potential For Ultrafast Dynamic Chemical Imaging With Few-Cycle Infrared Lasers, Toru Morishita, Anh-Thu Le, Zhangjin Chen, C. D. Lin

Physics Faculty Research & Creative Works

We studied the photoelectron spectra generated by an intense few cycle infrared laser pulse. By focusing on the angular distributions of the back rescattered high energy photoelectrons, we show that accurate differential elastic scattering cross-sections of the target ion by free electrons can be extracted. Since the incident direction and the energy of the free electrons can be easily changed by manipulating the laser's polarization, intensity and wavelength, these extracted elastic scattering cross-sections, in combination with more advanced inversion algorithms, may be used to reconstruct the effective single-scattering potential of the molecule, thus opening up the possibility of using few-cycle …

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Charge Exchange And X-Ray Emission Cross Sections For Multiply Charged Ions Colliding With H₂O, Sebastian Otranto, Ronald E. Olson

Physics Faculty Research & Creative Works

Total and state selective nl-electron capture cross sections are presented for highly charged ions Z=4-10, 14, 18, and 26 colliding with water molecules. The energy range investigated was from 10 eV/amu (v=0.02 a.u.) to 100 keV/amu (v=2 a.u.). An initialization for the 1B1 and 3A1 orbitals of the water molecule is introduced based on the one center expansion of Moccia and compared to our previous studies based on a hydrogenic approximation within the microcanonical ensemble. The Z dependence of the calculated total cross sections is in reasonable agreement with the recent data of Mawhorter et al. [Phys. Rev. A 75, …

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Isotope Shift In The Dielectronic Recombination Of Three-Electron ANd⁵⁷⁺, Carsten Brandau, Ch Kozhuharov, Zoltan Harman, Alfred K. Muller, Stefan Schippers, S. Kozhedub, Dietrich Bernhardt, Stefan Bohm, J. Jacobi, Eric W. Schmidt, Paul H. Mokler, Fritz J. Bosch, Heinz Jurgen Kluge, Th H. Stohlker, Klaus Beckert, P. Beller, Fritz Nolden, Markus Steck, Alexandre Gumberidze, Regina Reuschl, Uwe Spillmann, Fred John Currell, I. I. Tupitsyn, Vladimir M. Shabaev, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

Isotope shifts in dielectronic recombination spectra were studied for Li-like ^ANd⁵⁷⁺ ions with A = 142 and A = 150. From the displacement of resonance positions energy shifts δE^{142 150}(2s-2p_1/2) = 40.2(3)(6) meV [(stat)(sys)] and δE^{142 150}(2s - 2p_3/2) = 42.3(12)(20)meV of 2s - 2p_j transitions were deduced. An evaluation of these values within a full QED treatment yields a change in the mean-square charge radius of ^{142 150}δ⟨ r²⟩ = -1.36(1)(3) fm². The approach is conceptually new and combines the advantage of a …

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Quasiclassical Description Of Bremsstrahlung Accompanying Α Decay Including Quadrupole Radiation, Ulrich D. Jentschura, A. I. Milstein, Ivan S. Terekhov, H. Boie, Heiko Scheit, Dirk Schwalm

Physics Faculty Research & Creative Works

We present a quasiclassical theory of α decay accompanied by bremsstrahlung with a special emphasis on the case of ²¹⁰Po, with the aim of finding a unified description that incorporates both the radiation during the tunneling through the Coulomb wall and the finite energy E_γ of the radiated photon up to E_γ~Q_α | √/η, where Q_α is the α-decay Q-value and η is the Sommerfeld parameter. The corrections with respect to previous quasiclassical investigations are found to be substantial, and excellent agreement with a full quantum mechanical treatment is achieved. Furthermore, we find that …

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Reparameterization Invariance Of Nrqed Self-Energy Corrections And Improved Theory For Excited D States In Hydrogenlike Systems, Benedikt J. Wundt, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

Canonically, the quantum electrodynamic radiative corrections in bound systems have been evaluated in photon energy regularization, i.e., using a noncovariant overlapping parameter that separates the high-energy relativistic scales of the virtual quanta from the nonrelativistic domain. Here, we calculate the higher-order corrections to the one-photon self-energy calculation with three different overlapping parameters (photon energy, photon mass and dimensional regularization) and demonstrate the reparameterization invariance of nonrelativistic quantum electrodynamics (NRQED) using this particular example. We also present new techniques for the calculation of the low-energy part of this correction, which lead to results for the Lamb shift of highly excited states …

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Projectile Angular-Differential Cross Sections For Transfer And Transfer Excitation In Proton Collisions With Helium, M. Zapukhlyak, T. Kirchner, Ahmad Hasan, B. Tooke, Michael Schulz

Physics Faculty Research & Creative Works

Projectile angular-differential cross sections for single-transfer and transfer excitation have been calculated with the two-center extension of the nonperturbative basis generator method for 5-200 keV proton-helium collisions. The calculations are based on the independent electron model, and the eikonal approximation has been used to extract angular-differential cross sections from impact-parameter-dependent transition amplitudes. The present results are compared with experimental and previous theoretical data where available. In particular, we consider the ratio of transfer excitation to single capture versus double excitation to single excitation at intermediate energies. An experimentally observed structure in this ratio at a scattering angle about 0.5 mrad …

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Accurate Retrieval Of Structural Information From Laser-Induced Photoelectron And High-Order Harmonic Spectra By Few-Cycle Laser Pulses, Toru Morishita, Anh-Thu Le, Zhangjin Chen, C. D. Lin

Physics Faculty Research & Creative Works

By analyzing accurate theoretical results from solving the time-dependent Schrödinger equation of atoms in few-cycle laser pulses, we established the general conclusion that laser-generated high-energy electron momentum spectra and high-order harmonic spectra can be used to extract accurate differential elastic scattering and photo-recombination cross sections of the target ion with free electrons, respectively. Since both electron scattering and photoionization (the inverse of photo-recombination) are the conventional means for interrogating the structure of atoms and molecules, this result implies that existing few-cycle infrared lasers can be implemented for ultrafast imaging of transient molecules with temporal resolution of a few femtoseconds.

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Higher-Order Contributions Observed In Three-Dimensional (E,2e) Cross-Section Measurements At 1-Kev Impact Energy, M. Dürr, C. Dimopoulou, B. Najjari, A. Dorn, K. Bartschat, I. Bray, D. V. Fursa, Zhangjin Chen, Don H. Madison, J. Ullrich

Physics Faculty Research & Creative Works

We present experimental and theoretical fully differential cross sections for single ionization by fast, 1-keV (v=8.6 a.u.) electron impact. The cross sections were measured using a momentum imaging technique for electrons and ions (reaction microscope), which covers a large fraction of the emission angles for emitted low-energy electrons (EeV) and a wide range of scattering angles. Therefore comprehensive data sets are obtained for ionizing collisions at small relative momentum and energy transfer from the projectile to the target system. The experimental data are compared with predictions from several state-of-the-art theoretical calculations. At this high impact energy the calculated cross section …

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Dominance Of Virtual Delbrück Scattering For The Photon Emission By Nuclei In Relativistic Electron-Nucleus And Nucleus-Nucleus Collisions, Ilya F. Ginzburg, Ulrich D. Jentschura, Valery G. Serbo

Physics Faculty Research & Creative Works

We consider the contribution of virtual Delbrück scattering to the photon emission by nuclei in the collision of two ultra-relativistic nuclei Z₁ Z₂ → Z₁ Z₂ γ and electron-nucleus collisions e Z → e Z γ, in the photon energy range m ≪ E_γ ≪ m γ, where m is the electron mass and γ is the Lorentz factor of the colliding nucleus. The discussed process has no infrared divergence. The total cross section is 50 barn for the Pb-Pb collisions at the LHC collider. The spectral distribution obtained is considerably larger than for ordinary …

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Full-Text Articles in Physical Sciences and Mathematics

Large Contribution Of Virtual Delbrück Scattering To The Emission Of Photons By Relativistic Nuclei In Nucleus-Nucleus And Electron-Nucleus Collisions, Ilya F. Ginzburg, Ulrich D. Jentschura, Valery G. Serbo

Physics Faculty Research & Creative Works

Investigating Many-Electron Exchange Effects In Electron-Heavy-Atom Scattering, S. Bellm, J. Lower, Z. Stegen, Don H. Madison, H. P. Saha

Physics Faculty Research & Creative Works

The Decomposition Of Yba₂Cu₃O₇₋Δ Doped Into Ba₂Yruo₆, H. A. Blackstead, William B. Yelon, M. Kornecki, M. P. Smylie, P. J. Mcginn, Jinbo Yang, Qingsheng Cai, William Joseph James

Physics Faculty Research & Creative Works

Potential For Ultrafast Dynamic Chemical Imaging With Few-Cycle Infrared Lasers, Toru Morishita, Anh-Thu Le, Zhangjin Chen, C. D. Lin

Physics Faculty Research & Creative Works

Charge Exchange And X-Ray Emission Cross Sections For Multiply Charged Ions Colliding With H₂O, Sebastian Otranto, Ronald E. Olson

Physics Faculty Research & Creative Works

Physics Faculty Research & Creative Works

Quasiclassical Description Of Bremsstrahlung Accompanying Α Decay Including Quadrupole Radiation, Ulrich D. Jentschura, A. I. Milstein, Ivan S. Terekhov, H. Boie, Heiko Scheit, Dirk Schwalm

Physics Faculty Research & Creative Works

Reparameterization Invariance Of Nrqed Self-Energy Corrections And Improved Theory For Excited D States In Hydrogenlike Systems, Benedikt J. Wundt, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

Projectile Angular-Differential Cross Sections For Transfer And Transfer Excitation In Proton Collisions With Helium, M. Zapukhlyak, T. Kirchner, Ahmad Hasan, B. Tooke, Michael Schulz

Physics Faculty Research & Creative Works

Accurate Retrieval Of Structural Information From Laser-Induced Photoelectron And High-Order Harmonic Spectra By Few-Cycle Laser Pulses, Toru Morishita, Anh-Thu Le, Zhangjin Chen, C. D. Lin

Physics Faculty Research & Creative Works

Higher-Order Contributions Observed In Three-Dimensional (E,2e) Cross-Section Measurements At 1-Kev Impact Energy, M. Dürr, C. Dimopoulou, B. Najjari, A. Dorn, K. Bartschat, I. Bray, D. V. Fursa, Zhangjin Chen, Don H. Madison, J. Ullrich

Physics Faculty Research & Creative Works

Dominance Of Virtual Delbrück Scattering For The Photon Emission By Nuclei In Relativistic Electron-Nucleus And Nucleus-Nucleus Collisions, Ilya F. Ginzburg, Ulrich D. Jentschura, Valery G. Serbo

Physics Faculty Research & Creative Works