Surface heterostructure nanomechanical actuators with atomic resolution
Jan D. Makowski and Joseph J. Talghader
A continuously tunable vertical actuator with subnanometer resolution is presented. It consists of a heterostructure cantilever which has collapsed over a 125 nm thick nanogap. Its operating principle relies on the temperature dependence of the adhesion energy between two InGaAs surface quantum wel ... [Appl. Phys. Lett. 90, 183111 (2007)] published Wed May 2, 2007.
Photonic crystal effect on light emission from InGaN/GaN multi-quantum-well structures
Keunjoo Kim, Jaeho Choi, Sang Cheol Jeon, Jin Soo Kim, and Hee Mok Lee
Triangular hole arrays with nanoscaled lattice constants of 230 and 460 nm were fabricated on a p-type GaN epitaxial layer grown on an InGaN/GaN multi-quantum-well light emitting diode structure by metal-organic chemical vapor deposition. The hole geometries of dry-etched thin slabs for triangular ... [Appl. Phys. Lett. 90, 181115 (2007)] published Wed May 2, 2007.
f[sub K]/f[sub pi] in full QCD with domain wall valence quarks
S. R. Beane, P. F. Bedaque, K. Orginos, and M. J. Savage NPLQCD Collaboration
We compute the ratio of pseudoscalar decay constants f[sub K]/f[sub pi] using domain-wall valence quarks and rooted improved Kogut-Susskind sea quarks, at a lattice spacing of b~0.125 fm. By employing continuum chiral perturbation theory, we extract the Gasser-Leutwyler low-energy constant L[sub 5] ... [Phys. Rev. D 75, 094501 (2007)] published Wed May 2, 2007.
Generalized parton distributions from hadronic observables: Zero skewness
Saeed Ahmad, Heli Honkanen, Simonetta Liuti, and Swadhin K. Taneja
We propose a physically motivated parametrization for the unpolarized generalized parton distributions. At zero value of the skewness variable, zeta, the parametrization is constrained by simultaneously fitting the experimental data on both the nucleon elastic form factors and the deep inelastic str ... [Phys. Rev. D 75, 094003 (2007)] published Wed May 2, 2007.
Square-gradient mechanism of surface scattering in quasi-one-dimensional rough waveguides
M. Rendon, F. M. Izrailev, and N. M. Makarov
We develop a perturbative approach that allows one to study surface scattering in quasi-one-dimensional waveguides with rough boundaries. Our approach is based on the construction of an effective bulk potential of a very complicated structure. A detailed analysis of this potential reveals that apart ... [Phys. Rev. B 75, 205404 (2007)] published Tue May 1, 2007.
Dimensional transition of Cd[sub x]Zn[sub 1 - x]Te nanostructures grown on ZnTe layers
H. S. Lee, H. L. Park, and T. W. Kim
The atomic force microscopy images showed that the dimensional structural transformation from Cd[sub x]Zn[sub 1x]Te quantum dots (QDs) with Cd mole fractions of 0.5 and 0.6 to Cd[sub x]Zn[sub 1x]Te quantum wires occurred at a Cd mole fraction of 0.8. Photoluminescence spectra showed that the exciton ... [Appl. Phys. Lett. 90, 181909 (2007)] published Tue May 1, 2007.
Photon number resolving detector based on a quantum dot field effect transistor
B. E. Kardynal, S. S. Hees, A. J. Shields, C. Nicoll, I. Farrer et al.
The authors show that the change in current flowing through the channel of a quantum dot field effect transistor is proportional to the number (N) of photons absorbed from an incident pulse. Distinct features due to photon number state up to N=3 are resolved. With improvement of external quantum eff ... [Appl. Phys. Lett. 90, 181114 (2007)] published Tue May 1, 2007.
Effective degrees of freedom and gluon condensation in the high temperature deconfined phase
P. Castorina and M. Mannarelli
The equation of state and the properties of matter in the high temperature deconfined phase are analyzed by a quasiparticle approach for T>1.2T[sub c]. In order to fix the parameters of our model we employ the lattice QCD data of energy density and pressure. First we consider the pure SU(3) gluon pl ... [Phys. Rev. C 75, 054901 (2007)] published Tue May 1, 2007.
Anti--de Sitter/Conformal-Field-Theory Calculation of Screening in a Hot Wind
Hong Liu, Krishna Rajagopal, and Urs Achim Wiedemann
One of the challenges in relating experimental measurements of the suppression in the number of J/psi mesons produced in heavy ion collisions to lattice QCD calculations is that whereas the lattice calculations treat J/psi mesons at rest, in a heavy ion collision a c[overline c] pair can have a sign ... [Phys. Rev. Lett. 98, 182301 (2007)] published Tue May 1, 2007.
Recoil-Proton Polarization in High-Energy Deuteron Photodisintegration with Circularly Polarized Photons
X. Jiang, J. Arrington, F. Benmokhtar, A. Camsonne, J. P. Chen et al. Jefferson Lab Hall A Collaboration
We measured the angular dependence of the three recoil-proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made prediction ... [Phys. Rev. Lett. 98, 182302 (2007)] published Tue May 1, 2007.
Sharp Superconductor-Insulator Transition in Short Wires
Dganit Meidan, Yuval Oreg, and Gil Refael
Recent experiments on short MoGe nanowires show a sharp superconducting-insulating transition at the universal resistance R[sub Q]=h/(4e[sup 2]), contrary to the expectation of a smooth temperature dependence of the resistance for such Josephson-like systems. We present a self-consistent renormaliza ... [Phys. Rev. Lett. 98, 187001 (2007)] published Tue May 1, 2007.
Collider implications of a nonuniversal Higgs boson
C. D. McMullen and S. Nandi
We consider in detail the possibility that the Higgs is wholly or partially excluded from propagating into one otherwise universal extra dimension. This exclusion of the Higgs from propagating into an otherwise universal extra dimension violates tree-level Kaluza-Klein number conservation in the Yuk ... [Phys. Rev. D 75, 095001 (2007)] published Tue May 1, 2007.
Quark Model Calculations of the N to Delta Reaction
M. M. Giannini
The electromagnetic excitation of the nucleon resonances is studied in the framework of Constituent Quark Models. Particular attention is devoted to the transition to the Delta resonance and to the issue of a possible deformation of hadronic systems, mainly in connection with the problem of the quad ... [AIP Conf. Proc. 904, 179 (2007)] published Mon Apr 30, 2007.
Charge Form Factors and Nucleon Shape
A. J. Buchmann
To obtain further information on the geometric shape of the nucleon, the proton charge form factor is decomposed into two terms, which are connected respectively with a spherically symmetric and an intrinsic quadrupole part of the proton's charge density. Quark model relations are employed to derive ... [AIP Conf. Proc. 904, 110 (2007)] published Mon Apr 30, 2007.
Overview: The Shape of Hadrons
A. M. Bernstein and C. N. Papanicolas
In this article we address the physical basis of the deviation of hadron shapes from spherical symmetry (non-spherical amplitudes) with focus on the nucleon and Delta. An overview of both the experimental methods and results and the current theoretical understanding of the issue is presented. At the ... [AIP Conf. Proc. 904, 1 (2007)] published Mon Apr 30, 2007.
Self-assembly of periodic nanoclusters of Si and Ge along atomically straight steps of a vicinal Si(111)
Takeharu Sekiguchi, Shunji Yoshida, Yohei Shiren, Kohei M. Itoh, Josef Mysliveček et al.
The very initial stage of the molecular beam epitaxy of Si and Ge on Si(111)7 x 7 substrates with atomically straight steps has been studied by scanning tunneling microscopy and spectroscopy. The atomically straight steps have been prepared on a miscut Si(111) substrate by annealing at 830 degrees ... [J. Appl. Phys. 101, 081702 (2007)] published Fri Apr 27, 2007.
Quantum ballistic phenomena in nanostructures of paraelectric PbTe
G. Grabecki
This article reviews recent developments in the physics of lead telluride nanostructures. PbTe is a IVVI narrow gap paraelectric semiconductor, characterized by the huge static dielectric constant epsilon>1000 at helium temperatures. Methods of gating and nanostructure fabrication of modulation dope ... [J. Appl. Phys. 101, 081722 (2007)] published Fri Apr 27, 2007.
Collisional energy loss of nonasymptotic jets in a quark-gluon plasma
A. Adil, M. Gyulassy, W. Horowitz, and S. Wicks
We calculate the collisional energy loss suffered by a heavy (charm) quark created at a finite time within a quark-gluon plasma in the classical linear response formalism as in Peigne et al. [J. High Energy Phys. 04 (2006) 011]. We pay close attention to the problem of formulating a suitable current ... [Phys. Rev. C 75, 044906 (2007)] published Fri Apr 27, 2007.
Dimensional Control of Antilocalization and Spin Relaxation in Quantum Wires
S. Kettemann
The weak localization correction to the conductivity of quantum wires with linear Rashba-Dresselhaus spin-orbit coupling is derived analytically as function of wire width W. The spin relaxation rate is found to decrease as W becomes smaller than the spin-precession length L[sub SO]. As a result, the ... [Phys. Rev. Lett. 98, 176808 (2007)] published Fri Apr 27, 2007.
Shear Viscosity in Weakly Coupled N = 4 Super Yang-Mills Theory Compared to QCD
Simon C. Huot, Sangyong Jeon, and Guy D. Moore
We compute the shear viscosity of weakly coupled [script N]=4 supersymmetric Yang-Mills theory. Our result for eta/s, the viscosity to entropy-density ratio, is many times smaller than the corresponding weak-coupling result in QCD. This suggests that eta/s of QCD near the transition point is several ... [Phys. Rev. Lett. 98, 172303 (2007)] published Fri Apr 27, 2007.
Top quark signatures of Higgsless models
Christian Schwinn
In these proceedings I describe the use of tree level unitarity to constrain top quark signatures of Higgsless electroweak models and discuss implications for collider phenomenology. (C)2007 American Institute of Physics ... [AIP Conf. Proc. 903, 427 (2007)] published Fri Apr 27, 2007.
Meson resonance creation in carbon-carbon interactions at 4.2 AGeV/c
I. Pićurić, S. Backović, and D. Krpić
We present results on investigations of the invariant mass distributions and transverse momentum spectra of rho[sup 0](770) meson in C+C collisions at 4.2 AGeV/c. We used a 2-m propane bubble chamber exposed to beams from the Dubna synchrophasotron. From invariant masses of pion pairs the mass and t ... [AIP Conf. Proc. 899, 574 (2007)] published Fri Apr 27, 2007.
Single Anomalous Production of the Fourth SM Family Quarks at Future e + e-, ep, and pp Colliders
A. K. Ciftci, R. Ciftci, S. Sultansoy, and H. Duran Yildiz
Possible single productions of fourth SM family u[sub 4] and d[sub 4] quarks via anomalous interactions at the e[sup +]e[sup ], ep, and pp colliders are investigated. Signatures of such anomalous processes are discussed at above colliders comparatively. (C)2007 American Institute of Physics ... [AIP Conf. Proc. 899, 227 (2007)] published Fri Apr 27, 2007.
The Investigation of Bose Excitations in Quark-Gluon Plasma in Lightcone Gauge
Elsen Veli Veliev, Jale Y. Sungu, Gulsah Bozkir, and Nurcan Aksit
We investigate collective excitations in quark-gluon plasma at high temperatures. Ultrarelativistic plasmas are of importance in cosmology, astrophysics, and high energy nucleus-nucleus collisions. One of the fundamental properties of a thermal field theory at finite temperatures is the collective e ... [AIP Conf. Proc. 899, 223 (2007)] published Fri Apr 27, 2007.
ATLAS Sensitivity to Anomalous WWV Couplings
Lj. Simić, N. Vranješ, I. Mendaš, and D. S. Popović
We present the strategy in extracting information on triple gauge boson couplings in WW production and summarize the expected limits on WWV couplings from the ATLAS experiment at the LHC. (C)2007 American Institute of Physics ... [AIP Conf. Proc. 899, 219 (2007)] published Fri Apr 27, 2007.
Calculations of [script g][sub alpha[sub 0] omega gamma ], [script g][sub f[sub 0] omega gamma ], [script g][sub alpha[sub 0] rho gamma ] and [script g][sub f[sub 0] rho gamma ] Coupling Constants in QCD Sum Rules
C. Aydin, M. Bayar, and A. H. Yilmaz
The coupling constants of alpha[sub 0] --> omegagamma, f[sub 0] --> omegagamma, alpha[sub 0] --> rhogamma, and f[sub 0] --> rhogamma are calculated using 3-point QCD sum rules. We estimate the coupling constants [script g][sub alpha[sub 0]omegagamma], [script g][sub f[sub 0]omegagamma], [script g][s ... [AIP Conf. Proc. 899, 185 (2007)] published Fri Apr 27, 2007.
Flavor Democracy in Particle Physics
Saleh Sultansoy
The flavor democracy hypothesis (or, in other words, democratic mass matrix approach) was introduced in seventies taking in mind three Standard Model (SM) families. Later, this idea was disfavored by the large value of the t-quark mass. In nineties the hypothesis was revisited assuming that extra SM ... [AIP Conf. Proc. 899, 49 (2007)] published Fri Apr 27, 2007.
Fast switchable electrochromic properties of tungsten oxide nanowire bundles
Sung Jong Yoo, Ju Wan Lim, Yung-Eun Sung, Young Hwa Jung, Hong Goo Choi et al.
The authors prepared uniformly shaped WO[sub 2.72] nanowire bundles using the solvothermal synthesis method. They investigated the potential of the WO[sub 2.72] nanowire bundles to be used as a cathode electrode for electrochromic devices and the effect of the Li[sup +] insertion (or extraction) kin ... [Appl. Phys. Lett. 90, 173126 (2007)] published Fri Apr 27, 2007.
Time- and locally resolved photoluminescence of semipolar GaInN/GaN facet light emitting diodes
Thomas Wunderer, Peter Bruckner, Joachim Hertkorn, Ferdinand Scholz, Gareth J. Beirne et al.
The authors investigate the carrier lifetime and photoluminescence (PL) intensity of a semipolar GaInN/GaN sample which was realized by growing five GaInN/GaN quantum wells on the {1[overline 1]01} side facets of selectively grown n-GaN stripes that have a triangular shape running along the <11[over ... [Appl. Phys. Lett. 90, 171123 (2007)] published Fri Apr 27, 2007.