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## Full-Text Articles in Physical Sciences and Mathematics

Following Coherent Multichannel Nuclear Wave Packets In Pump-Probe Studies Of O₂ With Ultrashort Laser Pulses, S. Xue, H. Du, B. Hu, C. D. Lin, Anh-Thu Le

#### Following Coherent Multichannel Nuclear Wave Packets In Pump-Probe Studies Of O₂ With Ultrashort Laser Pulses, S. Xue, H. Du, B. Hu, C. D. Lin, Anh-Thu Le

*Physics Faculty Research & Creative Works*

We reexamine the recent pump-probe experiment with O₂ using short intense infrared laser pulses theoretically. Using parameters that closely mimic the experimental conditions and taking into account the angle-dependent population redistribution due to resonant coupling between the relevant states, we show that the observed kinetic energy release spectra, including the energy-dependent structure and the quantum beat frequencies, can be accurately reproduced. Our results reveal additional important channels that were missed earlier. In particular, the strong contributions from O₂+a^{4}Π_{u} and b^{4}Σ_{b}- states lead to the possibility of observing the interchannel beating. We further demonstrate ...

Virtual Resonant Emission And Oscillatory Long-Range Tails In Van Der Waals Interactions Of Excited States: Qedtreatment And Applications, Ulrich D. Jentschura, Chandra Mani Adhikari, Vincent Debierre

#### Virtual Resonant Emission And Oscillatory Long-Range Tails In Van Der Waals Interactions Of Excited States: Qedtreatment And Applications, Ulrich D. Jentschura, Chandra Mani Adhikari, Vincent Debierre

*Physics Faculty Research & Creative Works*

We report on a quantum electrodynamic (QED) investigation of the interaction between a ground state atom with another atom in an excited state. General expressions, applicable to any atom, are indicated for the long-range tails that are due to virtual resonant emission and absorption into and from vacuum modes whose frequency equals the transition frequency to available lower-lying atomic states. For identical atoms, one of which is in an excited state, we also discuss the mixing term that depends on the symmetry of the two-atom wave function (these evolve into either the gerade or the ungerade state for close approach ...

Dirac Hamiltonian And Reissner-Nordström Metric: Coulomb Interaction In Curved Space-Time, J. H. Noble, Ulrich D. Jentschura

#### Dirac Hamiltonian And Reissner-Nordström Metric: Coulomb Interaction In Curved Space-Time, J. H. Noble, Ulrich D. Jentschura

*Physics Faculty Research & Creative Works*

We investigate the spin-1/2 relativistic quantum dynamics in the curved space-time generated by a central massive charged object (black hole). This necessitates a study of the coupling of a Dirac particle to the Reissner-Nordström space-time geometry and the simultaneous covariant coupling to the central electrostatic field. The relativistic Dirac Hamiltonian for the Reissner-Nordström geometry is derived. A Foldy-Wouthuysen transformation reveals the presence of gravitational and electrogravitational spin-orbit coupling terms which generalize the Fokker precession terms found for the Dirac-Schwarzschild Hamiltonian, and other electrogravitational correction terms to the potential proportional to α^{n}G, where α is the fine-structure constant ...

Muonic Bound Systems, Virtual Particles, And Proton Radius, Ulrich D. Jentschura

#### Muonic Bound Systems, Virtual Particles, And Proton Radius, Ulrich D. Jentschura

*Physics Faculty Research & Creative Works*

The proton radius puzzle questions the self-consistency of theory and experiment in light muonic and electronic bound systems. Here we summarize the current status of virtual particle models as well as Lorentz-violating models that have been proposed in order to explain the discrepancy. Highly charged one-electron ions and muonic bound systems have been used as probes of the strongest electromagnetic fields achievable in the laboratory. The average electric field seen by a muon orbiting a proton is comparable to hydrogenlike uranium and, notably, larger than the electric field in the most advanced strong-laser facilities. Effective interactions due to virtual annihilation ...

Classical Description Of H(1s) And H* (N=2) For Cross-Section Calculations Relevant To Charge-Exchange Diagnostics, N. D. Cariatore, Sebastian Otranto, Ronald E. Olson

#### Classical Description Of H(1s) And H* (N=2) For Cross-Section Calculations Relevant To Charge-Exchange Diagnostics, N. D. Cariatore, Sebastian Otranto, Ronald E. Olson

*Physics Faculty Research & Creative Works*

In this work, we introduce a classical trajectory Monte Carlo (CTMC) methodology, specially conceived to provide a more accurate representation of charge-exchange processes between highly charged ions and H(1s) and H* (n=2). These processes are of particular relevance in power fusion reactor programs, for which charge-exchange spectroscopy has become a useful plasma diagnostics tool. To test the methodology, electron-capture reactions from these targets by C^{6+},N^{7+}, and O^{8+} are studied at impact energies in the 10-150keV/amu range. State-selective cross sections are contrasted with those predicted by the standard microcanonical formulation of the CTMC method ...

Long-Range Atom-Wall Interactions And Mixing Terms: Metastable Hydrogen, Ulrich D. Jentschura

#### Long-Range Atom-Wall Interactions And Mixing Terms: Metastable Hydrogen, Ulrich D. Jentschura

*Physics Faculty Research & Creative Works*

We investigate the interaction of metastable 2S hydrogen atoms with a perfectly conducting wall, including parity-breaking S-P mixing terms (with full account of retardation). The neighboring 2P_{1/2} and 2P_{3/2} levels are found to have a profound effect on the transition from the short-range, nonrelativistic regime, to the retarded form of the Casimir-Polder interaction. The corresponding P state admixtures to the metastable 2S state are calculated. We find the long-range asymptotics of the retarded Casimir-Polder potentials and mixing amplitudes for general excited states, including a fully quantum electrodynamic treatment of the dipole-quadrupole mixing term. The decay width ...

Fine-Structure Constant For Gravitational And Scalar Interactions, Ulrich D. Jentschura

#### Fine-Structure Constant For Gravitational And Scalar Interactions, Ulrich D. Jentschura

*Physics Faculty Research & Creative Works*

Starting from the coupling of a relativistic quantum particle to the curved Schwarzschild space time, we show that the Dirac-Schwarzschild problem has bound states and calculate their energies including relativistic corrections. Relativistic effects are shown to be suppressed by the gravitational fine-structure constant α_{G}=Gm_{1}m_{2}/(ℏ*c*), where G is Newton's gravitational constant, c is the speed of light, and m_{1} and m_{2} ≫ m_{1} are the masses of the two particles. The kinetic corrections due to space-time curvature are shown to lift the familiar (n,j) degeneracy of the energy levels of the ...

Evidence For Magnetic Clusters In Ni₁₋ₓVₓ Close To The Quantum Critical Concentration, R. Wang, S. Ubaid-Kassis, A. Schroeder, P. J. Baker, F. L. Pratt, S. J. Blundell, T. Lancaster, I. Franke, J. S. Möller, Thomas Vojta

#### Evidence For Magnetic Clusters In Ni₁₋ₓVₓ Close To The Quantum Critical Concentration, R. Wang, S. Ubaid-Kassis, A. Schroeder, P. J. Baker, F. L. Pratt, S. J. Blundell, T. Lancaster, I. Franke, J. S. Möller, Thomas Vojta

*Physics Faculty Research & Creative Works*

The d-metal alloy Ni_{1-x}V_{x} undergoes a quantum phase transition from a ferromagnetic ground state to a paramagnetic ground state as the vanadium concentration x is increased. We present magnetization, ac-susceptibility and muon-spin relaxation data at several vanadium concentrations near the critical concentration x_{c} ~ 11.6 % at which the onset of ferromagnetic order is suppressed to zero temperature. Below x_{c}, the muon data reveal a broad magnetic field distribution indicative of a long-range ordered ferromagnetic state with spatial disorder. We show evidence of magnetic clusters in the ferromagnetic phase and close to the phase boundary in ...

Universality Of Returning Electron Wave Packet In High-Order Harmonic Generation With Midinfrared Laser Pulses, Anh-Thu Le, Hui Wei, Cheng Jin, Vu Ngoc Tuoc, Toru Morishita, C. D. Lin

#### Universality Of Returning Electron Wave Packet In High-Order Harmonic Generation With Midinfrared Laser Pulses, Anh-Thu Le, Hui Wei, Cheng Jin, Vu Ngoc Tuoc, Toru Morishita, C. D. Lin

*Physics Faculty Research & Creative Works*

We show that a returning electron wave packet in high-order harmonic generation (HHG) with midinfrared laser pulses converges to a universal limit for a laser wavelength above about 3µm. The results are consistent among the different methods: a numerical solution of the time-dependent Schrödinger equation, the strong-field approximation, and the quantum orbits theory. We further analyze how the contribution from different electron "trajectories" survives the macroscopic propagation in the medium. Our result thus provides a new framework for investigating the wavelength scaling law for the HHG yields.

Criticality And Quenched Disorder: Harris Criterion Versus Rare Regions, Thomas Vojta, José A. Hoyos

#### Criticality And Quenched Disorder: Harris Criterion Versus Rare Regions, Thomas Vojta, José A. Hoyos

*Physics Faculty Research & Creative Works*

We employ scaling arguments and optimal fluctuation theory to establish a general relation between quantum Griffiths singularities and the Harris criterion for quantum phase transitions in disordered systems. If a clean critical point violates the Harris criterion, it is destabilized by weak disorder. At the same time, the Griffiths dynamical exponent z' diverges upon approaching the transition, suggesting unconventional critical behavior. In contrast, if the Harris criterion is fulfilled, power-law Griffiths singularities can coexist with clean critical behavior, but z' saturates at a finite value. We present applications of our theory to a variety of systems including quantum spin chains ...

Dynamical (E,2e) Studies Of Tetrahydropyran And 1,4-Dioxane, J. D. Builth-Williams, G. Da Silva, L. Chiari, D. B. Jones, Hari Chaluvadi, Don H. Madison, M. J. Brunger

#### Dynamical (E,2e) Studies Of Tetrahydropyran And 1,4-Dioxane, J. D. Builth-Williams, G. Da Silva, L. Chiari, D. B. Jones, Hari Chaluvadi, Don H. Madison, M. J. Brunger

*Physics Faculty Research & Creative Works*

We present experimental and theoretical results for the electron-impact ionization of the highest occupied molecular orbitals of tetrahydropyran and 1,4-dioxane. Using an (e,2e) technique in asymmetric coplanar kinematics, angular distributions of the slow ejected electron, with an energy of 20 eV, are measured when incident electrons at 250 eV ionize the target and scatter through an angle of either -10° or -15°. The data are compared with calculations performed at the molecular 3-body distorted wave level. Fair agreement between the theoretical model and the experimental measurements was observed. The similar structures for these targets provide key insights for ...

Gravitationally Coupled Dirac Equation For Antimatter, Ulrich D. Jentschura

#### Gravitationally Coupled Dirac Equation For Antimatter, Ulrich D. Jentschura

*Physics Faculty Research & Creative Works*

The coupling of antimatter to gravity is of general interest because of conceivable cosmological consequences ("surprises") related to dark energy and the cosmological constant. Here, we revisit the derivation of the gravitationally coupled Dirac equation and find that the prefactor of a result given previously by Brill and Wheeler [Rev. Mod. Phys. 29, 465 (1957)] for the affine connection matrix is in need of a correction. We also discuss the conversion of the curved-space Dirac equation from the so-called "East-Coast" to the "West-Coast" convention, in order to bring the gravitationally coupled Dirac equation to a form where it can easily ...

Self-Energy Correction To The Hyperfine Splitting For Excited States, Benedikt J. Wundt, Ulrich D. Jentschura

#### Self-Energy Correction To The Hyperfine Splitting For Excited States, Benedikt J. Wundt, Ulrich D. Jentschura

*Physics Faculty Research & Creative Works*

The self-energy corrections to the hyperfine splitting is evaluated for higher excited states in hydrogenlike ions using an expansion in the binding parameter Zα, where Z is the nuclear-charge number and α is the fine-structure constant. We present analytic results for D, F, and G states, and for a number of highly excited Rydberg states, with principal quantum numbers in the range 13≤n≤16, and orbital angular momenta =n-2 and =n-1. A closed-form analytic expression is derived for the contribution of high-energy photons, valid for any state with ≥2 and arbitrary n, , and total angular momentum j. The low-energy ...

Fundamental Constants And Tests Of Theory In Rydberg States Of Hydrogenlike Ions, Ulrich D. Jentschura, Peter J. Mohr, Joseph Tan, Benedikt J. Wundt

#### Fundamental Constants And Tests Of Theory In Rydberg States Of Hydrogenlike Ions, Ulrich D. Jentschura, Peter J. Mohr, Joseph Tan, Benedikt J. Wundt

*Physics Faculty Research & Creative Works*

A comparison of precision frequency measurements to quantum electrodynamics (QED) predictions for Rydberg states of hydrogenlike ions can yield information on values of fundamental constants and test theory. With the results of a calculation of a key QED contribution reported here, the uncertainty in the theory of the energy levels is reduced to a level where such a comparison can yield an improved value of the Rydberg constant.

Relativistic Calculation Of The Two-Photon Decay Rate Of Highly Excited Ionic States, Ulrich D. Jentschura, Andrey S. Surzhykov

#### Relativistic Calculation Of The Two-Photon Decay Rate Of Highly Excited Ionic States, Ulrich D. Jentschura, Andrey S. Surzhykov

*Physics Faculty Research & Creative Works*

Based on quantum electrodynamics, we reexamine the two-photon decay of one-electron atoms. Special attention is paid to the calculation of the (two-photon) total decay rates which can be viewed as the imaginary part of the two-loop self-energy. We argue that our approach can be easily applied to the cases with a virtual state having an intermediate energy between the initial and the final state of the decay process leading, thus, to the resonance peaks in the two-photon energy distribution. In order to illustrate our approach, we obtain fully relativistic results, resolved into electric and magnetic multipole components, for the two-photon ...

Zeeman Splitting And G Factor Of The 1s²2s²2p ²P_{3/2} And ²P_{1/2} Levels In Ar¹³⁺, R. Soria Orts, Jose R. Crespo Lopez-Urrutia, Hjalmar Bruhns, Antonio J. Gonzalez, Zoltan Harman, Ulrich D. Jentschura, Christoph H. Keitel, Alain Lapierre, Hiroyuki Tawara, I. I. Tupitsyn, Joachim Hermann Ullrich, Andrey V. Volotka

#### Zeeman Splitting And G Factor Of The 1s²2s²2p ²P3/2 And ²P1/2 Levels In Ar¹³⁺, R. Soria Orts, Jose R. Crespo Lopez-Urrutia, Hjalmar Bruhns, Antonio J. Gonzalez, Zoltan Harman, Ulrich D. Jentschura, Christoph H. Keitel, Alain Lapierre, Hiroyuki Tawara, I. I. Tupitsyn, Joachim Hermann Ullrich, Andrey V. Volotka

*Physics Faculty Research & Creative Works*

The Zeeman line components of the magnetic-dipole (M1) 1s^{2} 2s^{2} ^{2} P_{1/2} -^{2}P_{3/2} transition in boronlike Ar^{13+} were experimentally resolved by high-precision emission spectroscopy using the Heidelberg electron beam ion trap. We determined the gyromagnetic (g) factors of the ground and first-excited levels to be g_{1/2} =0.663(7) and g_{3/2} =1.333(2), respectively. This corresponds to a measurement of the g factor of a relativistic electron in a bound non- S state of a multielectron ion with a 1.5 parts-per-thousand accuracy. The results are compared ...

Analysis Of Experimental Data For Ion-Impact Single Ionization Of Helium With Monte Carlo Event Generators Based On Quantum Theory, M. Dürr, B. Najjari, Michael Schulz, A. Dorn, R. Moshammer, A. B. Voitkiv, J. Ullrich

#### Analysis Of Experimental Data For Ion-Impact Single Ionization Of Helium With Monte Carlo Event Generators Based On Quantum Theory, M. Dürr, B. Najjari, Michael Schulz, A. Dorn, R. Moshammer, A. B. Voitkiv, J. Ullrich

*Physics Faculty Research & Creative Works*

Recent multiply differential experimental data taken with reaction microscopes severely challenge predictions of quantum mechanical few-body models. Here, we report on a thorough analysis of all known possible experimental resolution effects and their influence on the extracted cross sections. Using a Monte Carlo event generator to simulate true events on the basis of quantum calculations allows us to consistently incorporate all aspects of the experimental resolution of the reaction microscope. We study the effect of the instrumental function in single ionization of helium by 3.6 MeV/u Au53+ and 100 MeV/u C6+ ions and find it to significantly ...

Bremsstrahlung In Α Decay Reexamined, H. Boie, Heiko Scheit, Ulrich D. Jentschura, F. Kock, M. Lauer, A. I. Milstein, Ivan S. Terekhov, Dirk Schwalm

#### Bremsstrahlung In Α Decay Reexamined, H. Boie, Heiko Scheit, Ulrich D. Jentschura, F. Kock, M. Lauer, A. I. Milstein, Ivan S. Terekhov, Dirk Schwalm

*Physics Faculty Research & Creative Works*

A high-statistics measurement of bremsstrahlung emitted in the α decay of ^{210}Po has been performed, which allows us to follow the photon spectra up to energies of ~500keV. The measured differential emission probability is in good agreement with our theoretical results obtained within the quasiclassical approximation as well as with the exact quantum mechanical calculation. It is shown that, due to the small effective electric dipole charge of the radiating system, a significant interference between the electric dipole and quadrupole contributions occurs, which is altering substantially the angular correlation between the α particle and the emitted photon.

Two-Loop Bethe Logarithms For Non- S Levels, Ulrich D. Jentschura

#### Two-Loop Bethe Logarithms For Non- S Levels, Ulrich D. Jentschura

*Physics Faculty Research & Creative Works*

Two-loop Bethe logarithms are calculated for excited P and D states in hydrogenlike systems, and estimates are presented for all states with higher angular momenta. These results complete our knowledge of the P and D energy levels in hydrogen at the order of α^{8} m_{e}c^{2}, where me is the electron mass and c is the speed of light, and scale as Z^{6}, where Z is the nuclear charge number. Our analytic and numerical calculations are consistent with the complete absence of logarithmic terms of order (απ)^{2} (Zα)^{6} ln [(Zα)^{-2}] m_{e}c ...

Quantum Electrodynamic Corrections To The Hyperfine Structure Of Excited S States, Ulrich D. Jentschura, Vladimir A. Yerokhin

#### Quantum Electrodynamic Corrections To The Hyperfine Structure Of Excited S States, Ulrich D. Jentschura, Vladimir A. Yerokhin

*Physics Faculty Research & Creative Works*

State-dependent quantum electrodynamic corrections are evaluated for the hyperfine splitting of nS states for arbitrary principal quantum number n. The calculations comprise both the self-energy and the vacuum-polarization correction of order α(Zα) 2 EF and the recoil correction of order (Zα)^{2} (m/M) E_{F}. Higher-order corrections are summarized and partly reevaluated as well. Accurate predictions for hydrogen hyperfine splitting intervals of nS states with n=2,...,8 are presented. The results obtained are important due to steady progress in hydrogen spectroscopy for transitions involving highly excited S states.

Two-Photon Excitation Dynamics In Bound Two-Body Coulomb Systems Including Ac Stark Shift And Ionization, Martin K. Haas, Ulrich D. Jentschura, Christoph H. Keitel, Nikolai N. Kolachevsky, Maximilian Herrmann, Peter Fendel, Marc P. Fischer, Th H. Udem, Ronald Holzwarth, Theodor Wolfgang Hansch, Marlan O. Scully, Girish S. Agarwal

#### Two-Photon Excitation Dynamics In Bound Two-Body Coulomb Systems Including Ac Stark Shift And Ionization, Martin K. Haas, Ulrich D. Jentschura, Christoph H. Keitel, Nikolai N. Kolachevsky, Maximilian Herrmann, Peter Fendel, Marc P. Fischer, Th H. Udem, Ronald Holzwarth, Theodor Wolfgang Hansch, Marlan O. Scully, Girish S. Agarwal

*Physics Faculty Research & Creative Works*

One of the dominant systematic effects that shift resonance lines in high-precision measurements of two-photon transitions is the dynamic (ac) Stark shift. For suitable laser frequencies, the ac Stark shift acquires an imaginary part which corresponds to the rate of resonant one-photon ionization of electrons into a continuum state. At the current level of spectroscopic accuracy, the underlying time-dependent quantum dynamics governing the atomic two-photon excitation process must be well understood, and related considerations are the subject of the present paper. In order to illustrate the basic mechanisms in the transient regime, we investigate an analytically solvable model scenario for ...

Benchmarking High-Field Few-Electron Correlation And Qed Contributions In Hg⁷⁵⁺ To Hg⁷⁸⁺ Ions. Ii. Theory, Zoltan Harman, I. I. Tupitsyn, Anton N. Artemyev, Ulrich D. Jentschura, Christoph H. Keitel, Jose R. Crespo Lopez-Urrutia, Antonio J. Gonzalez, Hiroyuki Tawara, Joachim Hermann Ullrich

#### Benchmarking High-Field Few-Electron Correlation And Qed Contributions In Hg⁷⁵⁺ To Hg⁷⁸⁺ Ions. Ii. Theory, Zoltan Harman, I. I. Tupitsyn, Anton N. Artemyev, Ulrich D. Jentschura, Christoph H. Keitel, Jose R. Crespo Lopez-Urrutia, Antonio J. Gonzalez, Hiroyuki Tawara, Joachim Hermann Ullrich

*Physics Faculty Research & Creative Works*

Theoretical resonance energies for KLL dielectronic recombination into He-, Li-, Be-, and B-like Hg ions are calculated by various means and discussed in detail. We apply the multiconfiguration Dirac-Fock and the configuration interaction Dirac-Fock-Sturmian methods, and quantum electrodynamic many-body theory. The different contributions such as relativistic electron interaction, quantum electrodynamic contributions, and finite nuclear size and mass corrections are calculated and their respective theoretical uncertainties are estimated. Our final results are compared to experimental data from the preceding paper. The comparison of theoretical values with the experimental energies shows a good overall agreement for most transitions and illustrates the significance ...

Benchmarking High-Field Few-Electron Correlation And Qed Contributions In Hg⁷⁵⁺ To Hg⁷⁸⁺ Ions. I. Experiment, Antonio J. Gonzalez, Jose R. Crespo Lopez-Urrutia, Jean Pierre Braun, Gunter Brenner, Hjalmar Bruhns, Alain Lapierre, Vladimir Sergeyevich Mironov, R. Soria Orts, Hiroyuki Tawara, Michael Trinczek, Joachim Hermann Ullrich, Anton N. Artemyev, Zoltan Harman, Ulrich D. Jentschura, Christoph H. Keitel, James H. Scofield, I. I. Tupitsyn

#### Benchmarking High-Field Few-Electron Correlation And Qed Contributions In Hg⁷⁵⁺ To Hg⁷⁸⁺ Ions. I. Experiment, Antonio J. Gonzalez, Jose R. Crespo Lopez-Urrutia, Jean Pierre Braun, Gunter Brenner, Hjalmar Bruhns, Alain Lapierre, Vladimir Sergeyevich Mironov, R. Soria Orts, Hiroyuki Tawara, Michael Trinczek, Joachim Hermann Ullrich, Anton N. Artemyev, Zoltan Harman, Ulrich D. Jentschura, Christoph H. Keitel, James H. Scofield, I. I. Tupitsyn

*Physics Faculty Research & Creative Works*

The photorecombination of highly charged few-electron mercury ions Hg^{75+} to Hg^{78+} has been explored with the Heidelberg electron beam ion trap. By monitoring the emitted x rays (65-76 keV) and scanning the electron beam energy (45-54 keV) over the KLL dielectronic recombination (DR) region, the energies of state-selected DR resonances were determined to within ±4 eV (relative) and ±14 eV (absolute). At this level of experimental accuracy, it becomes possible to make a detailed comparison to various theoretical approaches and methods, all of which include quantum electrodynamic (QED) effects and finite nuclear size contributions (for a 1s electron ...

Nonrelativistic Qed Approach To The Lamb Shift, Ulrich D. Jentschura, Andrzej Czarnecki, Krzysztof Pachucki

#### Nonrelativistic Qed Approach To The Lamb Shift, Ulrich D. Jentschura, Andrzej Czarnecki, Krzysztof Pachucki

*Physics Faculty Research & Creative Works*

We calculate the one- and two-loop corrections of order α(Zα)^{6} and α^{2}(Zα)^{6}, respectively, to the Lamb shift in hydrogenlike systems using the formalism of nonrelativistic quantum electrodynamics. We obtain general results valid for all hydrogenic states with nonvanishing orbital angular momentum and for the normalized difference of S states. These results involve the expectation value of local effective operators and relativistic corrections to Bethe logarithms. The one-loop correction is in agreement with previous calculations for the particular cases of S, P, and D states. The two-loop correction in the order α^{2}(Zα)^{6} includes ...

Calculation Of The One- And Two-Loop Lamb Shift For Arbitrary Excited Hydrogenic States, Andrzej Czarnecki, Ulrich D. Jentschura, Krzysztof Pachucki

#### Calculation Of The One- And Two-Loop Lamb Shift For Arbitrary Excited Hydrogenic States, Andrzej Czarnecki, Ulrich D. Jentschura, Krzysztof Pachucki

*Physics Faculty Research & Creative Works*

General expressions for quantum electrodynamic corrections to the one-loop self-energy [of order α(Zα)^{6}] and for the two-loop Lamb shift [of order α^{2}(Zα)^{6}] are derived. The latter includes all diagrams with closed fermion loops. The general results are valid for arbitrary excited non-S hydrogenic states and for the normalized Lamb shift difference of S states, defined as Δ_{n}=n^{3}ΔE(nS)-ΔE(1S). We present numerical results for one-loop and two-loop corrections for excited S, P, and D states. In particular, the normalized Lamb shift difference of S states is calculated with an uncertainty ...

Precise Calculation Of Transition Frequencies Of Hydrogen And Deuterium Based On A Least-Squares Analysis, Ulrich D. Jentschura, Svetlana A. Kotochigova, Eric Olivier Le Bigot, Peter J. Mohr, Barry N. Taylor

#### Precise Calculation Of Transition Frequencies Of Hydrogen And Deuterium Based On A Least-Squares Analysis, Ulrich D. Jentschura, Svetlana A. Kotochigova, Eric Olivier Le Bigot, Peter J. Mohr, Barry N. Taylor

*Physics Faculty Research & Creative Works*

We combine a limited number of accurately measured transition frequencies in hydrogen and deuterium, recent quantum electrodynamics (QED) calculations, and, as an essential additional ingredient, a generalized least-squares analysis, to obtain precise and optimal predictions for hydrogen and deuterium transition frequencies. Some of the predicted transition frequencies have relative uncertainties more than an order of magnitude smaller than that of the g factor of the electron, which was previously the most accurate prediction of QED.

Relativistic Electron Correlation, Quantum Electrodynamics, And The Lifetime Of The 1s²2s²2p²P^{O}_{3/2} Level In Boronlike Argon, Alain Lapierre, Ulrich D. Jentschura, Jose R. Crespo Lopez-Urrutia, Jean Pierre Braun, Gunter Brenner, Hjalmar Bruhns, Daniel A. Fischer, Antonio J. Gonzalez, Zoltan Harman, Walter Johnson, Christoph H. Keitel, Vladimir Sergeyevich Mironov, C. J. Osborne, Guenther Sikler, R. Soria Orts, Vladimir M. Shabaev, Hiroyuki Tawara, I. I. Tupitsyn, Joachim Hermann Ullrich, Andrey V. Volotka

#### Relativistic Electron Correlation, Quantum Electrodynamics, And The Lifetime Of The 1s²2s²2p²PO3/2 Level In Boronlike Argon, Alain Lapierre, Ulrich D. Jentschura, Jose R. Crespo Lopez-Urrutia, Jean Pierre Braun, Gunter Brenner, Hjalmar Bruhns, Daniel A. Fischer, Antonio J. Gonzalez, Zoltan Harman, Walter Johnson, Christoph H. Keitel, Vladimir Sergeyevich Mironov, C. J. Osborne, Guenther Sikler, R. Soria Orts, Vladimir M. Shabaev, Hiroyuki Tawara, I. I. Tupitsyn, Joachim Hermann Ullrich, Andrey V. Volotka

*Physics Faculty Research & Creative Works*

The lifetime of the Ar^{13+} 1s^{2}2s^{2}2p^{2}P^{o}_{3/2} metastable level was determined at the Heidelberg Electron Beam Ion Trap to be 9.573(4)(5)ms(stat)(syst). The accuracy level of one per thousand makes this measurement sensitive to quantum electrodynamic effects like the electron anomalous magnetic moment (EAMM) and to relativistic electron-electron correlation effects like the frequency-dependent Breit interaction. Theoretical predictions, adjusted for the EAMM, cluster about a lifetime that is approximately 3σ shorter than our experimental result.

Complete Two-Loop Correction To The Bound-Electron Factor, Krzysztof Pachucki, Andrzej Czarnecki, Ulrich D. Jentschura, Vladimir A. Yerokhin

#### Complete Two-Loop Correction To The Bound-Electron Factor, Krzysztof Pachucki, Andrzej Czarnecki, Ulrich D. Jentschura, Vladimir A. Yerokhin

*Physics Faculty Research & Creative Works*

Within a systematic approach based on dimensionally regularized nonrelativistic quantum electrodynamics, we derive a complete result for the two-loop correction to order ( α/ π )^{2} ( Zα )^{4} for the g factor of an electron bound in an nS state of a hydrogenlike ion. The results obtained significantly improve the accuracy of the theoretical predictions for the hydrogenlike carbon and oxygen ions and influence the value of the electron mass inferred from g-factor measurements. D

Calculation Of Hydrogenic Bethe Logarithms For Rydberg States, Ulrich D. Jentschura, Peter J. Mohr

#### Calculation Of Hydrogenic Bethe Logarithms For Rydberg States, Ulrich D. Jentschura, Peter J. Mohr

*Physics Faculty Research & Creative Works*

We describe the calculation of hydrogenic (one-loop) Bethe logarithms for all states with principal quantum numbers 200. While, in principle, the calculation of the Bethe logarithm is a rather easy computational problem involving only the nonrelativistic (Schrdinger) theory of the hydrogen atom, certain calculational difficulties affect highly excited states, and in particular states for which the principal quantum number is much larger than the orbital angular momentum quantum number. Two evaluation methods are contrasted. One of these is based on the calculation of the principal value of a specific integral over a virtual photon energy. The other method relies directly ...

Relativistic And Radiative Corrections To The Mollow Spectrum, Jorg Evers, Ulrich D. Jentschura, Christoph H. Keitel

#### Relativistic And Radiative Corrections To The Mollow Spectrum, Jorg Evers, Ulrich D. Jentschura, Christoph H. Keitel

*Physics Faculty Research & Creative Works*

The incoherent inelastic part of the resonance fluorescence spectrum of a laser-driven atom is known as the Mollow spectrum [B. R. Mollow, Phys. Rev. 188, 1969 (1969)]. Starting from this level of description, we discuss theoretical foundations of high-precision spectroscopy using the resonance fluorescence light of strongly laser-driven atoms. Specifically, we evaluate the leading relativistic and radiative corrections to the Mollow spectrum, up to the relative orders of ( Z α )^{2} and α ( Z α )^{2} , respectively, and Bloch-Siegert shifts as well as stimulated radiative corrections involving off-resonant virtual states. Complete results are provided for the hydrogen 1 S - 2 ...