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CreatorTitleDescriptionSubjectDate
351 Wu, Yong-ShiIntegrable spin chain and operator mixing in N = 1,2 supersymmetric theoriesWe study operator mixing, due to planar one-loop corrections, for composite operators in D = 4 supersymmetric theories. We present some N = 1, 2 Yang-Mills and Wess-Zumino models, in which the planar one-loop anomalous dimension matrix in the sector of holomorphic scalars is identified with the Hami...2004-04
352 Dawson, KyleIntensive HST survey for z > 1 type Ia supernovae by targeting galaxy clustersWe present a new survey strategy to discover and study high redshift Type Ia supernovae (SNe Ia) using the Hubble Space Telescope (HST). By targeting massive galaxy clusters at 0.9 < z < 1.5, we obtain a twofold improvement in the efficiency of finding SNe compared to an HST field survey and a facto...Cosmological parameters2009-11-01
353 Vardeny, Zeev ValentineInterchain photogeneration of charged solitons in trans-(CH)xIn a recent Letter1 Rothberg, Jedju, Etemad, and Baker (RJEB) used a novel photoinduced-absorption (PA) technique to study charged-soliton (S ?) dynamics in trans-(CH)X with picosecond resolution by measuring transient PA at 0.45 eV. Both intrachain and interchain photogeneration of S ? are rep...Interchain photogeneration; Charged solitons; Trans-(CH)x1987
354 Lupton, John MarkIntermittency in second-harmonic radiation from plasmonic hot spots on rough silver filmsSurface enhancement of electromagnetic fields in plasmonic hot spots formed on rough silver films enables the observation of second-harmonic generation (SHG) from single metal nanoparticles. Nonlinear light scattering from these particles exhibits blinking in analogy to luminescence from single qu...Harmonic radiation; Plasmonic hot spots; Second harmonic generation; SHG2009-10
355 Lupton, John MarkIntrinsic room-temperature electrophosphorescence from a π-conjugated polymerElectrically induced phosphorescence from a poly(para-phenylene) ladder-type polymer is observed for the first time and characterized using time resolved spectroscopy. Short-lived phosphorescence is also observed in gated fluorescence spectra and is found to be quenched reversibly by oxygen. Therm...pi-conjugated polymers; Electrophosphorescence; Ladder-type polymer; Gated fluorescence spectra2002-09
356 Mishchenko, EugeneKinetic theory of shot noise in nondegenerate diffusive conductorsWe investigate current fluctuations in nondegenerate semiconductors, on length scales intermediate between the elastic and inelastic mean free paths. We present an exact solution of the nonlinear kinetic equations in the regime of space-charge limited conduction, without resorting to the drift app...Shot noise; Conductors; Boltzmann equation1999-08
357 Symko, Orest GeorgeLarge steps in long Josephson junctionsLarge constant voltage current-steps were observed in the IV-characteristics of long NbN-MgO-NbN Josephson junctions in the presence of external magnetic fields of a few Gauss. The steps are separated by a voltage AV corresponding roughly to 3 to 5 times the voltage spacing expected between adjacent...NbN-MgO-NbN; Long junctions; Current-steps; Voltage1993-03
358 Vardeny, Zeev ValentineLaser action in conducting polymersWe discuss both cooperative radiation and stimulated emission and consider their role in spectral narrowing of luminescent conducting polymers. We argue that cooperative radiation is favored in films with poor optical confinement. On the other hand, directional stimulated emission can be observed in...Laser action; Cooperative radiation; Stimulated emission; PPV; Disubstituted polyacetylene; Excitons; Spectral narrowing; Plastic lasers; Superfluorescence; Microcavity lasers1997
359 Vardeny, Zeev ValentineLaser action in polydialkylfluorene films: influence of low-temperature thermal treatmentWe have used a variety of optical probes to investigate the changes occurring upon low-temperature thermal treatment to the emissive properties of dialkyl substituted polyfluorene thin films. We found that the low-temperature-driven morphological changes involving aggregates formation, which are ob...Laser action; Polydialkylfluorene films; pi-conjugated polymers; Thermal treatment1999
360 Vardeny, Zeev Valentine; Gellermann, WernerLaser properties of luminescent conducting polymers in open resonatorsWe have investigated the lasing properties of several luminescent conducting polymers, i.e. DOO-PPV and the bi-substituted polyacetylenes PDPA-nBu, and PHJPA, dissolved in various polar and non-polar solvents. PP V polymers emit with high quantum efficiencies in broad emission bands centered in the ...Lasing; Amplified spontaneous emission; Spectral narrowing1997
361 Gerton, JordanLaser-free slow atom sourceA slow atom source, which does not rely on lasers, has been developed and characterized. The device, acting as an atomic low-pass velocity filter, utilizes permanent magnets to passively select the slow atoms present in a thermal atomic beam. Slow atoms are guided along a curved, conduction-limite...1999-11
362 Vardeny, Zeev ValentineLasing and stimulated emission in ∏-conjugated polymersRecent studies of lasing and stimulated emission in luminescent -conjugated polymers performed by our group are presented. Optical properties of cylindrical high- polymer microcavities are discussed. The emission spectra of plastic microring and microdisk lasers are measured and analyzed. Light-emi...Lasing; Stimulated emission; pi-conjugated polymers; Microcavities; Polymer lasers2000-01
363 Williams, Clayton C.Lateral dopant profiling in MOS structures on a 100 nm scale using scanning capacitance microscopyScanning capacitance microscopy and atomic force microscopy have been used to image the extent of lateral dopant diffusion in MOS structures. The data are capacitance vs. voltage measurements made on a submicron scale. The technique is non-destructive when imaging uncleaved samples. New experim...Scanning capacitance microscopy; Dopant profiling1990
364 Williams, Clayton C.Lateral dopant profiling with 200 nm resolution by scanning capacitance microscopyMeasurement of dopant density in silicon with lateral resolution on the 200 nm scale has been demonstrated with a near-field capacitance technique. The technique is based upon the measurement of local capacitance between a 100 nm tip and a semiconducting surface. Lateral dopant imaging is achieved b...Dopant profile; Doping density; Scanning capacitance microscopy1989
365 DeTar, CarletonLattice calculation of 1-+ hybrid mesons with improved Kogut-Susskind fermionsWe report on a lattice determination of the mass of the exotic 1-+ hybrid meson using an improved Kogut-Susskind action. Results from both quenched and dynamical quark simulations are presented. We also compare with earlier results using Wilson quarks at heavier quark masses. The results on lattice...Staggered quarks; Kogut-Susskind fermions2003-10
366 DeTar, CarletonLattice calculation of heavy-light decay constants with two flavors of dynamical quarksWe present results for f B , f Bs , f D , f Ds and their ratios in the presence of two flavors of light sea quarks (Nf52). We use Wilson light valence quarks and Wilson and static heavy valence quarks; the sea quarks are simulated with staggered fermions. Additional quenched simulations with nonpe...Wilson quarks; Chiral perturbation2002-11
367 Vardeny, Zeev ValentineLattice dynamics of CuClA satisfactory fit for CuCl phonon dispersion relations is obtained for the first time. This fit is achieved by modifying the branch assignment of a few 2 phonons and by applying a double-shell model to fit the observed phonon data.CuCl; Phonon dispersion relations1975-06
368 DeTar, CarletonLattice quantum chromodynamics comes of ageThe strength of the electron-photon interaction is characterized by the fine-structure constant α ≈ 1/137.036. Because α is small, quantum electrodynamics (QED), the theory of interacting electrons and photons, can be solved to very good approximation with the traditional technology of pencil an...Quarks; Gluons; Mesons; CKM matrix2004
369 DeTar, CarletonLattice results for the decay constant of heavy-light vector mesonsWe compute the leptonic decay constants of heavy-light vector mesons in the quenched approximation. The reliability of lattice computations for heavy quarks is checked by comparing the ratio of vector to pseudoscalar decay constant with the prediction of heavy quark effective theory in the limit o...Heavy quark effective theory; Wilson quarks2001-12
370 Vardeny, Zeev ValentineLeng et al. replyConwell, Rothberg, and Mizes (CRM) claim [1] that, as a result of chain length distribution and vibronic sidebands of electronic levels in PPV films, there is little correlation between increase of pump photon energy (Hw) and increase of electronic energy, and therefore data from excitation spectros...Chain length distribution; Vibronic sidebands; PPV films; Pump photon energy1994
371 DeTar, CarletonLeptonic decay constants fDs and fD in three flavor lattice QCDWe determine the leptonic decay constants fDs and fD in three flavor unquenched lattice QCD. We use O(a2)-improved staggered light quarks and O(a)-improved charm quarks in the Fermilab heavy quark formalism. Our preliminary results, based upon an analysis at a single lattice spacing, are fDs = 263+5...Decay constants2005-03
372 Gondolo, PaoloLight dark matter in leptophobic Z' modelsRecent experimental results in direct dark matter detection may be interpreted in terms of a dark matter particle of mass around 10 GeV=c2. We show that the required scenario can be realized with a new dark matter particle charged under an extra Abelian gauge boson Z0 that couples to quarks but not ...2012-01-01
373 DeTar, CarletonLight hadron properties with improved staggered quarksPreliminary results from simulations with 2+1 dynamical quark flavors at a lattice spacing of 0.09 fm are combined with earlier results at a = 0.13 fm. We examine the approach to the continuum limit and investigate the dependence of the pseudoscalar masses and decay constants as the sea and valence...Staggered quarks2003-05
374 DeTar, CarletonLight hadron spectrum - MILC results with the Kogut-Susskind and Wilson actions*We present the current status of our ongoing calculations of the light hadron spectrum with both Kogut-Susskind (KS) and Wilson quarks in the valence or quenched approximation. We discuss KS quarks first and find that the chiral extrapolation is potentially the biggest source of systematic error. F...Staggered quarks; Hadron spectrum; Kogut-Susskind quarks; Wilson quarks; Chiral extrapolation1998-01
375 DeTar, CarletonLight hadrons with improved staggered quarks: approaching the continuum limitWe have extended our program of QCD simulations with an improved Kogut-Susskind quark action to a smaller lattice spacing, approximately 0.09 fm. Also, the simulations with a ≈ 0.12 fm have been extended to smaller quark masses. In this paper we describe the new simulations and computations of the...Staggered quarks; Hadronic decay2004-11
351 - 375 of 924