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Physics Faculty Research & Creative Works

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Articles 1351 - 1380 of 1959

Full-Text Articles in Physical Sciences and Mathematics

Investigation Of Resonant Photoemission In Gd With X-Ray Linear Dichroism, Shubhra R. Mishra, Thomas K. Cummins, George Daniel Waddill, W. J. Gammon, Gerrit V. Van Der Laan, Kyle W. Goodman, James G. Tobin Jul 1999

Investigation Of Resonant Photoemission In Gd With X-Ray Linear Dichroism, Shubhra R. Mishra, Thomas K. Cummins, George Daniel Waddill, W. J. Gammon, Gerrit V. Van Der Laan, Kyle W. Goodman, James G. Tobin

Physics Faculty Research & Creative Works

The constructive summing of direct and indirect channels above the absorption threshold of a core level can cause a massive increase in the emission cross section, leading to a phenomenon called "resonant photoemission." Using novel magnetic linear dichroism in angular distribution photoelectron spectroscopy experiments and theoretical simulations, we have probed the nature of the resonant photoemission process in Gd metal. It now appears that temporal matching as well as energy matching is a requirement for true resonant photoemission.

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Influence Of Rare Regions On Magnetic Quantum Phase Transitions, Rajesh S. Narayanan, Thomas Vojta, Dietrich Belitz, Theodore R. Kirkpatrick Jun 1999

Influence Of Rare Regions On Magnetic Quantum Phase Transitions, Rajesh S. Narayanan, Thomas Vojta, Dietrich Belitz, Theodore R. Kirkpatrick

Physics Faculty Research & Creative Works

The effects of quenched disorder on the critical properties of itinerant quantum magnets are considered. Particular attention is paid to locally ordered rare regions that are formed in the presence of quenched disorder even when the bulk system is still in the nonmagnetic phase. It is shown that these local moments or instantons destroy the previously found critical fixed point in the case of antiferromagnets. In the case of itinerant ferromagnets, the critical behavior is unaffected by the rare regions due to an effective long-range interaction between the order parameter fluctuations.

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First Order Transitions And Multicritical Points In Weak Itinerant Ferromagnets, Dietrich Belitz, Theodore R. Kirkpatrick, Thomas Vojta Jun 1999

First Order Transitions And Multicritical Points In Weak Itinerant Ferromagnets, Dietrich Belitz, Theodore R. Kirkpatrick, Thomas Vojta

Physics Faculty Research & Creative Works

It is shown that the phase transition in low-Tc clean itinerant ferromagnets is generically of first order, due to correlation effects that lead to a nonanalytic term in the free energy. A tricritical point separates the line of first order transitions from Heisenberg critical behavior at higher temperatures. Sufficiently strong quenched disorder suppresses the first order transition via the appearance of a critical end point. A semiquantitative discussion is given in terms of recent experiments on MnSi, and predictions for other experiments are made.

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Effects Of Resonant Tunneling In Electromagnetic Wave Propagation Through A Polariton Gap, Lev I. Deych, Alexey Yamilov, Alexander A. Lisyansky May 1999

Effects Of Resonant Tunneling In Electromagnetic Wave Propagation Through A Polariton Gap, Lev I. Deych, Alexey Yamilov, Alexander A. Lisyansky

Physics Faculty Research & Creative Works

We consider tunneling of electromagnetic waves through a polariton band gap of a one-dimensional chain of atoms. We analytically show that a defect embedded in the structure gives rise to the resonance transmission at the frequency of a local polariton state associated with the defect. Numerical Monte Carlo simulations are used to examine properties of the electromagnetic band arising inside the polariton gap due to finite concen-tration of defects.

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Defect-Induced Resonant Tunneling Of Electromagnetic Waves Through A Polariton Gap, Lev I. Deych, Alexey Yamilov, Alexander A. Lisyansky May 1999

Defect-Induced Resonant Tunneling Of Electromagnetic Waves Through A Polariton Gap, Lev I. Deych, Alexey Yamilov, Alexander A. Lisyansky

Physics Faculty Research & Creative Works

We consider tunneling of electromagnetic waves through a polariton band gap of a 1-D chain of atoms. We analytically demonstrate that a defect embedded in the structure gives rise to the resonance transmission at the frequency of a local polariton state associated with the defect.

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Binary Nucleation Kinetics. Iv. Directional Properties And Cluster Concentrations At The Saddle Point, Gerald Wilemski Apr 1999

Binary Nucleation Kinetics. Iv. Directional Properties And Cluster Concentrations At The Saddle Point, Gerald Wilemski

Physics Faculty Research & Creative Works

Using a new approach, Stauffer's expression for the rate of steady state binary nucleation and Trinkaus's expression for the steady state cluster concentrations f are derived directly from the diffusion equation that governs the evolution of f in composition space. The behavior of φ (≡f/N, where N is the equilibrium cluster concentration) is explored since this function provides a characterization of the nucleating binary system that, to lowest order, is independent of the actual composition of the mother phase. The angle ω that describes the direction of ▽ φ at the saddle point differs, in general, from the angle φ …

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Geometrodynamical Formulation Of Two-Dimensional Dilaton Gravity, Marco Cavaglia Mar 1999

Geometrodynamical Formulation Of Two-Dimensional Dilaton Gravity, Marco Cavaglia

Physics Faculty Research & Creative Works

Two-dimensional matterless dilaton gravity with an arbitrary dilatonic potential can be discussed in a unitary way, both in the Lagrangian and canonical frameworks, by introducing suitable field redefinitions. The new fields are directly related to the original spacetime geometry and in the canonical picture they generalize the well-known geometrodynamical variables used in the discussion of the Schwarzschild black hole. So the model can be quantized using the techniques developed for the latter case. The resulting quantum theory exhibits the Birkhoff theorem at the quantum level.

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Impact Parameter Related Final N-Level Splitting Observed In Aligned Ion-Rydberg Collisions, K. R. Cornelius, Ronald E. Olson Jan 1999

Impact Parameter Related Final N-Level Splitting Observed In Aligned Ion-Rydberg Collisions, K. R. Cornelius, Ronald E. Olson

Physics Faculty Research & Creative Works

The classical trajectory Monte Carlo method has been used to calculate the final product principal quantum state n f-distributions in electron capture collisions involving a proton incident on a Rydberg hydrogen atom in an ni = 25 state. The generalized eccentricity, defined by orienting the classical eccentricity of the electron's orbit relative to the incident ion, was varied to show how the final state n f-levels depended on this quantity over the range of reduced collision speeds v* = vp/ve = 1.0-2.4. Plots of the final product n f-distributions at low reduced velocities show a resonance peak near n f …

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Calculation Of The Electron Self-Energy For Low Nuclear Charge, Ulrich D. Jentschura, Peter J. Mohr, Gerhard Soff Jan 1999

Calculation Of The Electron Self-Energy For Low Nuclear Charge, Ulrich D. Jentschura, Peter J. Mohr, Gerhard Soff

Physics Faculty Research & Creative Works

We present a nonperturbative numerical evaluation of the one-photon electron self-energy for hydrogenlike ions with low nuclear charge numbers Z = 1 to 5. Our calculation for the 1S state has a numerical uncertainty of 0.8 Hz for hydrogen and 13 Hz for singly ionized helium. Resummation and convergence acceleration techniques that reduce the computer time by about 3 orders of magnitude were employed in the calculation. The numerical results are compared to results based on known terms in the expansion of the self-energy in powers of Zα.

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X-Ray Absorption, Neutron Diffraction, And Mössbauer Effect Studies Of Mnzn-Ferrite Processed Through High-Energy Ball Milling, D. J. Fatemi, V. G. Harris, Mingxing Chen, Satish K. Malik, William B. Yelon, Gary J. Long, Amitabh Mohan Jan 1999

X-Ray Absorption, Neutron Diffraction, And Mössbauer Effect Studies Of Mnzn-Ferrite Processed Through High-Energy Ball Milling, D. J. Fatemi, V. G. Harris, Mingxing Chen, Satish K. Malik, William B. Yelon, Gary J. Long, Amitabh Mohan

Physics Faculty Research & Creative Works

MnZn-ferrite has been prepared via high-energy ball milling of elemental oxides MnO, ZnO, and α-Fe2O3. Neutron diffraction measurements suggest a high density of vacancies in a spinel structure. The spinel phase appears to comprise 99.8 wt % of the material in the sample milled for 40 h, with the remainder attributable to unreacted α-Fe2O3. The x-ray absorption near-edge structure was analyzed to provide an understanding of the charge state of the constituent Fe ions. This analysis reveals about 2/3 of Fe cations to be trivalent, increasing to about 3/4 after a 5 …

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Magnetic And Crystallographic Properties Of Lani₅₋ₓfex, C. Tan, Oran Allan Pringle, Mingxing Chen, William B. Yelon, J. Gebhardt, Naushad Ali, C. Y. Tai, G. K. Marasinghe, George Daniel Waddill, William Joseph James Jan 1999

Magnetic And Crystallographic Properties Of Lani₅₋ₓfex, C. Tan, Oran Allan Pringle, Mingxing Chen, William B. Yelon, J. Gebhardt, Naushad Ali, C. Y. Tai, G. K. Marasinghe, George Daniel Waddill, William Joseph James

Physics Faculty Research & Creative Works

No abstract provided.

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Double Electron Removal And Fragmentation Model Of The [Formula Presented] Molecule By Highly Charged Ions, C. J. Wood, Ronald E. Olson Jan 1999

Double Electron Removal And Fragmentation Model Of The [Formula Presented] Molecule By Highly Charged Ions, C. J. Wood, Ronald E. Olson

Physics Faculty Research & Creative Works

A five-body classical trajectory Monte Carlo model has been developed to study double electron removal from H2 by collisions with highly charged ions at impact energies ranging from 1 eV/u to 1 GeV/u. The longitudinal and transverse final-state correlation between ejected electrons is calculated for double ionization of H2 by impact of Se28+ at 3.6 MeV/u and U92+ at 1 GeV/u; the electron-electron interaction is dynamically included during the collision when one of the electron’s total energy becomes positive. Relativistic corrections are incorporated to reflect the Lorentz contraction of the projectile’s electric field. The cross-section dependence …

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Spin Dependent Tunneling, Peter M. Levy, Shufeng Zhang Jan 1999

Spin Dependent Tunneling, Peter M. Levy, Shufeng Zhang

Physics Faculty Research & Creative Works

During the past four years, researchers made significant advances in fabricating magnetic tunnel junctions with reproducible magnetic and magneto transport properties. Important developments include optimization of oxidation processes, discovery of new class of magnetic tunnel junctions, combination of spin dependent tunneling with the Coulomb blockade effect, and a better theoretical understanding of the I-V characteristics of magnetic tunnel junctions. These developments make them promising candidates for magnetic random-access memories. © Elsevier Science Ltd.

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Five-Body Calculations Of [Formula Presented] Fragmentation By [Formula Presented] Impact, C. R. Feeler, Ronald E. Olson, Robert D. Dubois, T. Schlathölter, O. Hadjar, R. Hoekstra, R. Morgenstern Jan 1999

Five-Body Calculations Of [Formula Presented] Fragmentation By [Formula Presented] Impact, C. R. Feeler, Ronald E. Olson, Robert D. Dubois, T. Schlathölter, O. Hadjar, R. Hoekstra, R. Morgenstern

Physics Faculty Research & Creative Works

A five-body classical trajectory Monte Carlo model has been developed to study fragmentation of diatomic molecules after double electron removal by highly charged ion impact. A systematic study of the final-state deuteron energy and momentum spectra has been conducted for Xe19+ + D2 collisions at impact energies ranging from 1 eV/u to 100 keV/u. At the highest projectile energies, the fragment energies and momenta are determined by the Coulomb explosion of the doubly ionized molecule via the known Franck-Condon transition for the isolated molecule. The deuterons are emitted back-to-back with nearly equal energies. At the lowest projectile energies, …

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Production Of Bound Μ⁺Μˉ Systems In Relativistic Heavy Ion Collisions, Ilya F. Ginzburg, Ulrich D. Jentschura, Savely Karshenboim, Frank Krauss, Valery G. Serbo, Gerhard Soff Dec 1998

Production Of Bound Μ⁺Μˉ Systems In Relativistic Heavy Ion Collisions, Ilya F. Ginzburg, Ulrich D. Jentschura, Savely Karshenboim, Frank Krauss, Valery G. Serbo, Gerhard Soff

Physics Faculty Research & Creative Works

Dimuonium (the bound system of two muons, the μ+ μ--atom system) has not been observed yet. In this paper we discuss the electromagnetic production of dimuonium at RHIC and LHC in relativistic heavy ion collisions. The production of parastates is analyzed in the equivalent photon approximation. For the treatment of orthostates, we develop a three-photon formalism. We determine the production rates at RHIC and LHC with an accuracy of a few percent and discuss problems related to the observation of dimuonium.

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Nonanalytic Magnetization Dependence Of The Magnon Effective Mass In Itinerant Quantum Ferromagnets, Dietrich Belitz, Theodore R. Kirkpatrick, Andrew J. Millis, Thomas Vojta Dec 1998

Nonanalytic Magnetization Dependence Of The Magnon Effective Mass In Itinerant Quantum Ferromagnets, Dietrich Belitz, Theodore R. Kirkpatrick, Andrew J. Millis, Thomas Vojta

Physics Faculty Research & Creative Works

The spin-wave dispersion relation in both clean and disordered itinerant quantum ferromagnets is calculated. It is found that effects akin to weak-localization physics cause the frequency of the spin waves to be a nonanalytic function of the magnetization m. For low frequencies Ω, small wave vectors k, and m→0, the dispersion relation is found to be of the form Ω=const x m1-αk2, with α = (4-d)/2 (2 < d < 4) for disordered systems, and α = (3-d) (1 < d < 3) for clean ones. In d = 4 (disordered) and d = 3 (clean), Ωαm ln (1/m) k2. Experiments to test these predictions are proposed.

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Differences Between Regular And Random Order Of Updates In Damage-Spreading Simulations, Thomas Vojta, Michael Schreiber Dec 1998

Differences Between Regular And Random Order Of Updates In Damage-Spreading Simulations, Thomas Vojta, Michael Schreiber

Physics Faculty Research & Creative Works

We investigate the spreading of damage in the three-dimensional Ising model by means of large-scale Monte Carlo simulations. Within the Glauber dynamics we use different rules for the order in which the sites are updated. We find that the stationary damage values and the spreading temperature are different for different update order. In particular, random update order leads to larger damage and a lower spreading temperature than regular order. Consequently, damage spreading in the Ising model is nonuniversal not only with respect to different update algorithms (e.g., Glauber vs heat-bath dynamics) as already known, but even with respect to the …

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Charge Exchange From D(N = 2) Atoms To Low-Z Receiver Ions, R. Hoekstra, H. Anderson, F. W. Bliek, M. Von Hellermann, C. F. Maggi, Ronald E. Olson, H. P. Summers Dec 1998

Charge Exchange From D(N = 2) Atoms To Low-Z Receiver Ions, R. Hoekstra, H. Anderson, F. W. Bliek, M. Von Hellermann, C. F. Maggi, Ronald E. Olson, H. P. Summers

Physics Faculty Research & Creative Works

To elucidate the influence on charge-exchange spectroscopy of metastable deuterium donors, the corresponding cross sections for state-selective charge transfer have been calculated using the classical trajectory Monte Carlo method. The cross sections for electron capture from D(n = 2) by fully stripped low-Z ions are contrasted with those for capture from ground state D to indicate the importance of metastable donors. Using the new data, effective emission coefficients for the spectral lines of H-like light impurities used in charge-exchange spectroscopy have been calculated. These results incorporate the presence of excited n = 2 donors in the beam and apply to …

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Double Differential Cross Section Of Helium Ionization By Proton Impact, A. L. Godunov, V. A. Schipakov, Michael Schulz Nov 1998

Double Differential Cross Section Of Helium Ionization By Proton Impact, A. L. Godunov, V. A. Schipakov, Michael Schulz

Physics Faculty Research & Creative Works

A theoretical analysis for doubly differential cross sections of the single ionization of helium by proton impact as a function of the scattering angle and projectile energy loss is presented. We have used two different theoretical methods. The first approach involved an approximate solution of Faddeev-Merkuriev equations for the three-body Coulomb problem. The second approach employed the expansion of the transition amplitude in the Born series over the projectile-target interaction up to second order. A relation between these two methods was established for the case of fast collisions. It has been demonstrated that, for small scattering angles, the post-collision interaction …

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Ultralow-Energy Electrons From Fast Heavy-Ion Helium Collisions: The “Target Cusp“, W. Schmitt, R. Moshammer, F. S.C. O'Rourke, H. Kollmus, L. Sarkadi, R. Mann, S. Hagmann, Ronald E. Olson, J. Ullrich Nov 1998

Ultralow-Energy Electrons From Fast Heavy-Ion Helium Collisions: The “Target Cusp“, W. Schmitt, R. Moshammer, F. S.C. O'Rourke, H. Kollmus, L. Sarkadi, R. Mann, S. Hagmann, Ronald E. Olson, J. Ullrich

Physics Faculty Research & Creative Works

Doubly differential cross sections d2σ / dν ‖ dν⊥ have been obtained by mapping the 3-dimensional velocity space of ultralow- and low-energy electrons \ (1.5 meV < = Ee < = 100 eV \) emitted in singly ionizing 3.6 MeV / u Au53+ on helium collisions. A sharp \ ( ΔEFWHMe⊥< = 22 meV \) asymmetric peak centered at = 0 is observed to emerge at ultralow energies from the strongly forward shifted low-energy electron velocity distribution. The shape of this "target cusp," which is very sensitive on the details of the two-center potential, is in excellent accord with theoretical predictions. © 1998 The American Physical Society.

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Do Interactions Increase Or Reduce The Conductance Of Disordered Electrons? It Depends!, Thomas Vojta, Frank Epperlein, Michael Schreiber Nov 1998

Do Interactions Increase Or Reduce The Conductance Of Disordered Electrons? It Depends!, Thomas Vojta, Frank Epperlein, Michael Schreiber

Physics Faculty Research & Creative Works

We investigate the influence of electron-electron interactions on the conductance of two-dimensional disordered spinless electrons. We present an efficient numerical method based on diagonalization in a truncated basis of Hartree-Fock states to determine with high accuracy the low-energy properties in the entire parameter space. We find that weak interactions increase the dc conductance in the strongly localized regime while they decrease the dc conductance for weak disorder. Strong interactions always decrease the conductance. We also study the localization of single-particle excitations at the Fermi energy which turns out to be only weakly influenced by the interactions.

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Essential Role Of Correlations In Governing Charge Transport In Disordered Organic Materials, Sergei V. Novikov, David H. Dunlap, Vasudev M. Kenkre, Paul Ernest Parris, Anatoly V. Vannikov Nov 1998

Essential Role Of Correlations In Governing Charge Transport In Disordered Organic Materials, Sergei V. Novikov, David H. Dunlap, Vasudev M. Kenkre, Paul Ernest Parris, Anatoly V. Vannikov

Physics Faculty Research & Creative Works

The transport of photoinjected charges in disordered organic films is often interpreted using a formula based on a Gaussian disorder model (GDM) that neglects spatial correlations due to charge-dipole interactions, even though such correlations have recently been shown to explain the universal electric field dependence observed in these systems. Based on extensive computer simulations of a 3D disorder model that includes such correlations, we present a new formula for analyzing experiments that accurately describes transport in these materials.

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Comparison Of Electron-Atom Collision Parameters For S To P Transitions Under Reversal Of Energy Transfer, Max Shurgalin, Andrew James Murray, William R. Macgillivray, M. C. Standage, Don H. Madison, Kathrin D. Winkler, Igor Bray Nov 1998

Comparison Of Electron-Atom Collision Parameters For S To P Transitions Under Reversal Of Energy Transfer, Max Shurgalin, Andrew James Murray, William R. Macgillivray, M. C. Standage, Don H. Madison, Kathrin D. Winkler, Igor Bray

Physics Faculty Research & Creative Works

Inelastic and superelastic electron scattering from the optically prepared 32P3/2 state of sodium has enabled atomic collision parameters to be deduced for the 4S-3P deexcitation and the 3S-3P excitation processes. These data are compared with convergent close coupling and second order distorted wave Born calculations. For excitation, both theories agree with experiment, whereas for deexcitation the close coupling theory is in better agreement. A long-standing proposal relating to the sign of the transferred angular momentum is not supported.

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Ionization Of Aligned Rydberg Atoms By Ion Impact, K. R. Cornelius, J. Wang, Ronald E. Olson Oct 1998

Ionization Of Aligned Rydberg Atoms By Ion Impact, K. R. Cornelius, J. Wang, Ronald E. Olson

Physics Faculty Research & Creative Works

The classical trajectory Monte Carlo method has been used to calculate capture and ionization cross sections and final-state electron momentum distributions in H+ + H(n = 25) collisions to show how the collision mechanisms evolve over the range of intermediate projectile speeds v* = vp/ve = 1.0-5.0. A circular Rydberg target was aligned in two orientations defined by the orbital angular momentum vector of the electron being either antiparallel or perpendicular to the incident momentum vector of the projectile. Aligning the target atom in this manner helps us to single out specific collision processes otherwise obscured in a randomly oriented …

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Evidence Of Initial-State Two-Center Effects For (E, 2e) Reactions, Sindu P. Jones, Don H. Madison Oct 1998

Evidence Of Initial-State Two-Center Effects For (E, 2e) Reactions, Sindu P. Jones, Don H. Madison

Physics Faculty Research & Creative Works

Coincidence, or (e, 2e), measurements of electron-impact ionization of atoms have established that the largest values of triply differential cross sections are obtained in collisions involving small momentum transfer to the target. Absolute measurements for these reactions are now available for hydrogen at 54.4-eV impact energy, and relative data have recently been reported at 27.2 eV. Previous theoretical works have concentrated on employing asymptotically correct two-center wave functions for the final state, leaving the initial state described by the Born approximation. Here we report results for which asymptotically correct two-center wave functions are used for both the initial and final …

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Shakeoff Measurement Of The L = 3 States Of Barium, Heider N. Ereifej, J. Greg Story Sep 1998

Shakeoff Measurement Of The L = 3 States Of Barium, Heider N. Ereifej, J. Greg Story

Physics Faculty Research & Creative Works

Isolated core excitation was used to produce low-energy continuum electrons in the l = 3 angular momentum state of barium. Data were taken over a region of energy that coincided with the energy of the 6p3/2nf doubly excited states. Analysis of the data using multichannel quantum defect theory allowed the measurement of the widths of the 6p3/2nf states and the energy-dependent phase of the continuum electronic wave functions due to interaction with the doubly excited states. The phase of the continuum electrons is shown to vary continuously with energy, due to the anomalously broad widths of …

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Low-Field Hopping Among Randomly-Distributed Sites With Uncorrelated Energetic Disorder, Paul Ernest Parris Sep 1998

Low-Field Hopping Among Randomly-Distributed Sites With Uncorrelated Energetic Disorder, Paul Ernest Parris

Physics Faculty Research & Creative Works

The low-field mobility μ of a small concentration of charge carriers hopping among a random distribution of transport sites is studied, as a function of the mean interparticle spacing ρ and the temperature T, for model systems having different site-energy distribution functions. For a uniform density of states our calculations show that the mobility obeys empirical scaling laws similar to those found in the theory of variable-range hopping. For a binary distribution of site energies we observe a crossover as a function of site density between trap-limited conduction and trap-mediated conduction. For a Gaussian density of states our results confirm …

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Protein Fragmentation Due To Slow Highly Charged Ion Impact, Christiane Ruehlicke, Dieter Schneider, Markus Schneider, Robert D. Dubois, Rod Balhorn Sep 1998

Protein Fragmentation Due To Slow Highly Charged Ion Impact, Christiane Ruehlicke, Dieter Schneider, Markus Schneider, Robert D. Dubois, Rod Balhorn

Physics Faculty Research & Creative Works

We present first results of experiments on the fragmentation of biomolecules using highly charged heavy ions. Fragmentation and modification of oligopeptides, such as dimerization and attachment of ionic salt components, have been observed by means of mass spectrometry. Plasmid DNA molecules were imaged with an atomic force microscope after ion irradiation and profound molecular damage was found.

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Nature Of Resonant Photoemission In Gd, Shubhra R. Mishra, Thomas K. Cummins, George Daniel Waddill, W. J. Gammon, Gerrit V. Van Der Laan, Kyle W. Goodman, James G. Tobin Aug 1998

Nature Of Resonant Photoemission In Gd, Shubhra R. Mishra, Thomas K. Cummins, George Daniel Waddill, W. J. Gammon, Gerrit V. Van Der Laan, Kyle W. Goodman, James G. Tobin

Physics Faculty Research & Creative Works

The phenomenon of resonant photoemission happens when, in addition to a direct photoemission channel, a second indirect channel opens up as the absorption threshold of a core level is crossed. A massive increase in emission cross section can occur, but the nature of the process remains clouded. Using novel magnetic linear dichroism in photoelectron spectroscopy experiments and theoretical calculations, we can now clearly demonstrate that temporal matching of the processes as well as energy matching is a requirement for true "resonant photoemission.".

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Next-To-Leading Order Qcd Corrections For The B⁰B⁰ Mixing With An Extended Higgs Sector, Jorg Org Urban, Frank Krauss, Ulrich D. Jentschura, Gerhard Soff Jul 1998

Next-To-Leading Order Qcd Corrections For The B⁰B⁰ Mixing With An Extended Higgs Sector, Jorg Org Urban, Frank Krauss, Ulrich D. Jentschura, Gerhard Soff

Physics Faculty Research & Creative Works

We present a calculation of the B0B0 mixing including next-to-leading order (NLO) QCD corrections within the Two-Higgs Doublet Model (2HDM). The QCD corrections at NLO are contained in the factor denoted by η2 which modifies the result obtained at the lowest order of perturbation theory. In the Standard Model case, we confirm the results for η2 obtained by Buras, Jamin and Weisz [Nucl. Phys, B 347 (1990) 491]. The factor η2 is gauge and renormalization prescription invariant and it does not depend on the infrared behaviour of the theory, which constitutes an important test …

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