| 1. |
- Schael, S, et al.
(author)
-
Precision electroweak measurements on the Z resonance
- 2006
-
In: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
-
Research review (peer-reviewed)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Fu, Ying, et al.
(author)
-
Energy band structure and spectral gain characteristics of dilute-nitride zinc blende InGaNAs quantum wells embedded in GaAs and GaNAs barriers
- 2006
-
In: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 100:7
-
Journal article (peer-reviewed)abstract
- The spectral gain characteristics of dilute-nitride zinc blende InxGa1-xNyAs1-y quantum wells embedded in GaNy1As1-y1 barriers have been investigated experimentally and theoretically. Two samples, both with the gain peak at 1300 nm, were studied for comparison. One has a high nitrogen concentration in the quantum well with the surrounding barriers being pure GaAs. The other has a lower and uniform nitrogen concentration in the quantum well and the barriers (GaNAs barriers). Measurements show the redshift of the gain peak induced by the incorporation of nitrogen and difference in the spectral gain characteristics. The energy band structures and spectral gain characteristics are analyzed theoretically using the standard eight-band k center dot p theory. It is shown that the introduction of nitrogen atoms in the GaAs barriers reduces the barrier height for the central quantum well so that the energy sublevels in the conduction band becomes condensed. The condensation of the conduction-band energy sublevels reduces the peak gain and makes the gain spectrum narrower, in agreement with measurements.
|
|
| 5. |
- Han, Y., et al.
(author)
-
Critical Thickness and Radius for Axial Heterostructure Nanowires Using Finite Element Method
- 2009
-
In: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 9:5, s. 1921-1925
-
Journal article (peer-reviewed)abstract
- Finite-element methods are used to simulate a heterostructured nanowire grown on a compliant mesa substrate. The critical thickness is calculated based on the overall energy balance approach. The strain field created by the first pair of misfit dislocations, which offsets the initial coherent strain field, is simulated. The local residual strain is used to calculate the total residual strain energy. The three-dimensional model shows that there exists a radius-dependent critical thickness below which no misfit dislocations could be generated. Moreover, this critical thickness becomes infinity for a radius less than some critical values. The simulated results are in good agreement with the experimental data. The critical radius from this work is smaller than that obtained from previous models that omit the interaction between the initial coherent strain field and the dislocation-induced strain field.
|
|
| 6. |
- Liu, F., et al.
(author)
-
Silicon-chip-based frequency quadrupling for optical millimeter-wave signal generation
- 2009
-
In: Optoelectronic Materials and Devices IV. - : SPIE - International Society for Optical Engineering. ; , s. 763105-
-
Conference paper (peer-reviewed)abstract
- We propose a prototype of a silicon-chip-based frequency quadrupling system integrating a single-drive silicon Mach-Zehnder modulator and a race-track resonator as an optical differentiator. A proof-of-concept demonstration of 40-GHz millimeter-wave signal generation using 10-GHz driving signal is experimentally provided. The factors that impacting the purity of the RF spectrum are discussed through simulation.
|
|
| 7. |
- Liu, F., et al.
(author)
-
Silicon-chip-based frequency quadrupling for optical millimeter-wave signal generation
- 2009
-
In: 2009 Asia Communications and Photonics Conference and Exhibition, ACP 2009. - Washington, D.C. : OSA. - 9781557528773 ; , s. 5377263-
-
Conference paper (peer-reviewed)abstract
- We propose a prototype of a silicon-chip-based frequency quadrupling system integrating a single-drive silicon Mach-Zehnder modulator and a microring resonator. A proof-of-concept demonstration of 40-GHz millimeter-wave signal generation using 10-GHz driving signal is experimentally provided.
|
|
| 8. |
- Qiu, Min, et al.
(author)
-
Transformation Optics for Designing Superlenses
- 2009
-
In: ICEAA. - NEW YORK : IEEE. ; , s. 944-947
-
Conference paper (peer-reviewed)abstract
- We show that by using the recently emerged transformation optics, it is possible to design perfect lenses in new geometries with an imaging performance almost equivalent to the well studied perfect slab lens. In addition, the theory of transformation optics generalizes the complementary bilayer lenses to many other material compositions, including cases where passive or active obstacles are involved in the lens system.
|
|
| 9. |
- Tian, Yu-Peng, et al.
(author)
-
Investigations and facile synthesis of a series of novel multi-functional two-photon absorption materials
- 2007
-
In: Journal of Materials Chemistry. - : Royal Society of Chemistry (RSC). - 0959-9428 .- 1364-5501. ; 17:34, s. 3646-3654
-
Journal article (peer-reviewed)abstract
- Six centrosymmetric D-(pi-A)(3) structural triphenylamine derivatives that can be used as two- photon photopolymerization and optical data storage chromophores, tris[ 4-( 4- pyridylethenyl) phenyl] amine ( 1), tris[ 4-( 2- pyridylethenyl) phenyl] amine ( 2), tris( 4- cyanoethenylphenyl) amine ( 3), tris[ 4- butylacrylatephenyl] amine ( 4), tris[ 4- methylacrylatephenyl] amine ( 5) and tris[ 4- acrylicethenylphenyl] amine ( 6), have been successfully synthesized via a triple palladium-catalyzed Heck coupling reaction, and the novel chromophores were fully characterized by elemental analysis, IR, (1)H-NMR and ESIMS. The structure for 3 was determined by single crystal X-ray diffraction study. One- and two-photon absorption and fluorescence in various solvents were experimentally investigated. Two-photon initiated polymerization microfabrication and optical data recording experiments were carried out under 780 nm laser radiation, and the possible polymerization mechanism is discussed based on theoretical calculations. All the six chromophores have relatively large two-photon absorption crosssections, and exhibit optical memory and highly efficient two-photon initiated polymerization abilities.
|
|
| 10. |
|
|
