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in subjects: "Electron-Electron Interactions"

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First results from Mark II at SPEAR

First results from the SLAC-LBL Mark II magnetic detector at SPEAR are presented. The performance of the detector is discussed and preliminary results are given on inclusive baryon production R/sub p + anti p/, R/sub ..lambda.. + anti ..lambda../, on decay modes of the D mesons and on two-photon production of eta' mesons.

Date: May 1, 1979

Creator: Abrams, G. S.; Alam, M. S. & Blocker, C. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Heavy Meson Production at a Low-Energy Photon Collider

A low-energy {gamma}{gamma} collider has been discussed in the context of a testbed for a {gamma}{gamma} interaction region at the Next Linear Collider(NLC). We consider the production of heavy mesons at such a testbed using Compton-backscattered photons and demonstrate that their production rivals or exceeds those by BELLE, BABAR or LEP where they are produced indirectly via virtual {gamma}{gamma} luminosities.

Date: April 15, 2004

Creator: Asztalos, S

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Coulomb correlations and optical gap in polyacetylene

A model including both electron-phonon coupling (as in the SSH Hamiltonian) and electron-electron interactions (on-site term U, nearest-neighbor term V) is treated within the variational scheme of Gutswiller. It is shown that for weak electron-phonon coupling the primary effect is a bond-order wave induced by electronic correlation, whereas the lattice dimerization is a secondary effect. Correspondingly the optical gap is mainly due to electronic correlation.

Date: January 1, 1986

Creator: Baeriswyl, D. & Maki, K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Power corrections, renormalons and resummation

I briefly review three topics of recent interest concerning power corrections, renormalons and Sudakov resummation: (a) 1/Q corrections to event shape observables in e(+)e(-) annihilation, (b) power corrections in Drell-Yan production and (c) factorial divergences that arise in resummation of large infrared (Sudakov) logarithms in moment or `real` space.

Date: August 1, 1996

Creator: Beneke, M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Coulomb correlation effects in quasi-one-dimensional conductors

Recent results on the role of electron-electron (e-e) interactions - ''correlation effects'' - in quasi-one-dimensional conductors are reviewed. Within the Peierls-Hubbard model, the consequences of short range (on-site U and nearest neighbor V) e-e interactions for ground state properties, nonlinear excitations, and optical absorption are examined. Techniques include quantum Monte Carlo and weak and strong coupling perturbative arguments. 26 refs., 2 figs.

Date: January 1, 1986

Creator: Campbell, David K.; Baeriswyl, Dionys & Mazumdar, Sumit

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Beam-beam disruption and the case for a plasma lens in e{sup {minus}}e{sup {minus}} collisions

In an e{sup {minus}}e{sup {minus}} collider, the mutual disruption of the beams will significantly decrease the luminosity, different from the case of e{sup +}e{sup {minus}} colliders, where the mutual attraction of the oppositely-charged beams leads to a self-focusing effect. In this paper the authors estimate the beam disruption at SLC and NLC energies using ABEL simulations. They then give estimates of how a plasma lens might improve the luminosity in e{sup {minus}}e{sup {minus}} collisions.

Date: March 1, 1996

Creator: Chen, P.; Spitkovsky, A. & Weidemann, A.W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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A step closer to visualizing the electron___phonon interplay

The origin of the very high superconducting transition temperature (Tc) in ceramic copper oxide superconductors is one of the greatest mysteries in modern physics. In the superconducting state, electrons form pairs (known as Cooper pairs) and condense into the superfluid state to conduct electric current with zero resistance. For conventional superconductors, it is well established that the 2 electrons in a Cooper pair are 'bonded' by lattice vibrations (phonons), whereas in high-Tc superconduc… more

Date: January 4, 2011

Creator: Chen, Y. L.; Lee, W. S.; Shen, Z. X. & /Stanford U., Appl. Phys. Dept. /Stanford U., Phys. Dept. /SLAC, PULSE

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Precsion Supersymmetry Measurement at the e{minus} e{minus} Collider

Measurements of supersymmetric particle couplings provide important verification of supersymmetry. If some of the superpartners are at the multi-TeV scale, they will escape direct detection at planned future colliders. However, such particles induce nondecoupling corrections in processes involving the accessible superparticles through violations of the supersymmetric equivalence between gauge boson and gaugino couplings. These violations are analogous to the oblique corrections in the electrowe… more

Date: January 1, 1998

Creator: Cheng, H.-C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Quantum Monte-Carlo Study of Electron Correlation in Heterostructure Quantum Dots

The goal of this project is to study electron correlation in a confined geometry (quantum dots) within the two-dimensional quantum well in the sandwiches of two semiconductor materials. For these systems one is able to tune the electronic properties by controlling the size and the electron number, creating tremendous potential for novel applications. Much effort in this emerging field has been devoted to producing entangled states that are required for quantum information processing. At the sam… more

Date: November 12, 2006

Creator: Chou, Mei-Yin

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Amplitude Modulation of Atomic Wavefunctions - Final Technical Report

This project developed a novel wave function modulation technique. Other modulation techniques use tailored laser pulses to directly excite a time-dependent, modulated wave function from a ground state. Our technique began with one electron already excited to a time independent eigenfunction. Then, by using excitations of a second valence electron, we modulated the other wave function. Our technique had the benefit that it was very efficient, and required low power lasers with no need for preci… more

Date: August 1, 2001

Creator: Cooke, William E.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Theory of multi-electron recoil effects on x-ray lineshapes of metals

Within the change of self-consistent field approximation, x-ray spectra can be considerably richer in many-electron phenomena than once suspected. With the finite number of electrons method, these spectra can be evaluated for realistic electron-hole interactions in free electron metals. Preliminary results indicate that metals with band structure can also be treated this way. However, theories of final-state interactions in metals await the reliable determinations of the screened potential of a… more

Date: January 1, 1980

Creator: Dow, J. D.; Swarts, C. A.; Bowen, M. A.; Mehreteab, E. & Satpathy, S. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Comments on the possible use of the SLC as an e{sup -}e{sup -} collider

It has been suggested that the SLAC Linear Collider, which was designed to collide electrons with positrons, could be modified to collide electrons with electrons. A cursory examination of this suggestion leads us to conclude that such a modification is technically feasible, but by no means trivial. In this letter we outline the issues that must be addressed to realize this possibility.

Date: February 1, 1996

Creator: Erickson, R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Supersymmetry at linear colliders: The importance of being e{sup {minus}}e{sup {minus}}

Advantages of the e{sup {minus}}e{sup {minus}} option at linear colliders for the study of supersymmetry are highlighted. The fermion number violating process e{sup {minus}}e{sup {minus}} {yields} {tilde e}{sup {minus}}{tilde e}{sup {minus}} provides unique opportunities for studies of slepton masses and flavor mixings. In particular, slepton mass measurements at the 100 MeV level through threshold scans of scalar pair production may be possible. Such measurements are over an order of magnitude… more

Date: March 1, 1998

Creator: Feng, J.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Dye- and Semiconductor-Sensitized Nanoparticle Solar Cell Research at NREL

The major objective of this research program is to determine the operational characteristics key to efficient, low-cost, stable liquid-junction and solid-state solar cells based on sensitized nanoporous films (in collaboration with DOE's Office of Science Program). Toward this end, we are conducting experimental and theoretical studies to understand the unique physical and chemical factors governing cell performance. Current scientific issues addressed include the influence of film morphology, … more

Date: January 1, 2005

Creator: Frank, A. J.; Kopidakis, N.; Benkstein, K. D.; van de Lagemaat, J. & Neale, N. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Physics with low-energy e/sup +/e/sup /minus// and e/sup /minus//e/sup /minus// collisions at Tau-Charm Factory

The physics opportunities in e/sup /plus//e/sup /minus// collisions with /radical/s /approx equal/ 1-2 GeV and e/sup /minus//e/sup /minus// collisions with /radical/s /approximately/5 GeV at Tau-Charm Factory are being explored. The low-energy e/sup /plus//e/sup /minus// option allows precise measurements of e/sup /plus//e/sup /minus// cross sections into /pi/'s and /eta/'s and hence stringent tests of the conserved-vector-current (CVC) hypothesis in /tau/ decays. Precise measurement of the tot… more

Date: July 1, 1989

Creator: Gan, K.K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Bremsstrahlung radiation in high energy particle collisions in the visible region

Some features of bremsstrahlung radiation are reviewed for visible region photons with possible applications to ISA luminosity measurements. (auth)

Date: August 1, 1973

Creator: Goldhaber, M. & Muzinich, I. J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

The stochastic radiative transfer equation: quantum damping, Kirchoff's law and NLTE

A method is presented based on the theory of quantum damping, for deriving a self consistent but approximate form of the quantum transport for photons interacting with fully ionized electron plasma. Specifically, we propose in this paper a technique of approximately including the effects of background plasma on a photon distribution function without directly solving any kinetic equations for the plasma itself. The result is a quantum Langevin equation for the photon number operator; the quantum… more

Date: January 24, 2005

Creator: Graziani, F R

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Charged particle and neutron backgrounds in an e-e- interaction region at the NLC

We compare the detector background situation in an e{sup -} e{sup -} interaction region at the NLC with previous studies done of the NLC e{sup +} e{sup -} interaction region. We note from previous studies that the dominant source of detector backgrounds are the beamstrahlung pairs. Since these scale with luminosity, the reduction in luminosity in e{sup -} e{sup -} collisions leads to a reduction in detector backgrounds compared to the e{sup +} e{sup -} situation.

Date: March 6, 2000

Creator: Gronberg, J

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Time-resolved THz studies of carrier dynamics in semiconductors, superconductors, and strongly-correlated electron materials

Perhaps the most important aspect of contemporary condensed matter physics involves understanding strong Coulomb interactions between the large number of electrons in a solid. Electronic correlations lead to the emergence of new system properties, such as metal-insulator transitions, superconductivity, magneto-resistance, Bose-Einstein condensation, the formation of excitonic gases, or the integer and fractional Quantum Hall effects. The discovery of high-Tc superconductivity in particular was … more

Date: November 14, 2006

Creator: Kaindl, Robert A. & Averitt, Richard D.

Item Type: Book

Partner: UNT Libraries Government Documents Department

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Progress in LTE and non-LTE transport calculations

The physical processes in ionized gases are reviewed along with recent calculations of particular processes. Ongoing opacity calculations at Los Alamos are described. Some of the open issues in the calculation of physical processes relevant to opacities are discussed. 39 refs., 7 figs.

Date: January 1, 1989

Creator: Keady, J.J.; Huebner, W.F.; Abdallah, J. Jr.; Magee, N.H. Jr. (Los Alamos National Lab., NM (USA); Southwest Research Inst., San Antonio, TX (USA) & Los Alamos National Lab., NM (USA))

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Emergence of the Persistent Spin Helix in Semiconductor Quantum Wells

According to Noether's theorem, for every symmetry in nature there is a corresponding conservation law. For example, invariance with respect to spatial translation corresponds to conservation of momentum. In another well-known example, invariance with respect to rotation of the electron's spin, or SU(2) symmetry, leads to conservation of spin polarization. For electrons in a solid, this symmetry is ordinarily broken by spin-orbit (SO) coupling, allowing spin angular momentum to flow to orbital … more

Date: August 24, 2011

Creator: Koralek, Jake; Weber, Chris; Orenstein, Joe; Bernevig, Andrei; Zhang, Shoucheng; Mack, Shawn et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Spin Transport in Semiconductor heterostructures

The focus of the research performed under this grant has been the investigation of spin transport in magnetic semiconductor heterostructures. The interest in these systems is motivated both by their intriguing physical properties, as the physical embodiment of a spin-polarized Fermi liquid, as well as by their potential applications as spintronics devices. In our work we have analyzed several different problems that affect the spin dynamics in single and bi-layer spin-polarized two-dimensional … more

Date: February 22, 2011

Creator: Marinescu, Domnita Catalina

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Single-cycle nonlinear optics

Nonlinear optics plays a central role in the advancement of optical science and laser-based technologies. We report on the confinement of the nonlinear interaction of light with matter to a single wave cycle and demonstrate its utility for time-resolved and strong-field science. The electric field of 3.3-femtosecond, 0.72-micron laser pulses with a controlled and measured waveform ionizes atoms near the crests of the central wave cycle, with ionization being virtually switched off outside this … more

Date: November 5, 2008

Creator: Max-Planck-Institut fur Quantenoptik

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Final Technical Report on Physics Research

Results are summarized on theoretical considerations of the excited states of the Ca isotopes, experimental studies of the level structure of Ca42 and Ca44, studies of the production of circularly polarized bremsstrahlung by beta rays, the Moller scattering spectrometer, and the Moller scattering coincidence experiment.

Date: November 30, 1959

Creator: McCullen, J. D.; Kraushaar, J. J.; Woolum, J. C.; Sandifer, C. W.; Kliwer, J. K.; Baker, D. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department