Guiding and confining fast electrons by transient electric and magnetic fields with a plasma inverse cone

Copyright 2009 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Physics of Plasmas, 16(2), 020702, 2009 and may be found at http://dx.doi.org/10.1063/1.307592

On the behavior of ultraintense laser produced hot electrons in self-excited fields

Copyright 2007 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Physics of Plasmas, 14(4), 040706, 2007 and may be found at http://dx.doi.org/10.1063/1.272230

Elastic properties and inter-atomic bonding in new superconductor KFe2Se2 from first principles calculations

Very recently (November, 2010, PRB, 82, 180520R) the first 122-like ternary superconductor KxFe2Se2 with enhanced TC ~ 31K has been discovered. This finding has stimulated much activity in search of related materials and triggered the intense studies of their properties. Indeed already in 2010-2011 the superconductivity (TC ~ 27-33K) was also found in the series of new synthesized 122 phases such as CsxFe2Se2, RbxFe2Se2, (TlK)xFeySe2 etc. which have formed today the new family of superconducting iron-based materials without toxic As. Here, using the ab initio FLAPW-GGA method we have predicted for the first time the elastic properties for KFe2Se2 and discussed their interplay with inter-atomic bonding for this system. Our data reveal that the examined phase is relatively soft material. In addition, this system is mechanically stable, adopts considerable elastic anisotropy, and demonstrates brittleness. These conclusions agree with the bonding picture for KFe2Se2, where the inter-atomic bonding is highly anisotropic and includes ionic, covalent and metallic contributions.Comment: 8 pages, 2 figure

Study of ultraintense laser propagation in overdense plasmas for fast ignition

Copyright 2009 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Physics of Plasmas, 16(5), 056307, 2009 and may be found at http://dx.doi.org/10.1063/1.310191

New ternary ThCr2Si2-type iron-selenide superconducting materials: synthesis, properties and simulations

Very recently (November, 2010, PRB, 82, 180520R), the first ThCr2Si2-type ternary superconductor K0.8Fe2Se2 with enhanced TC ~ 31 K has been discovered. This finding has stimulated much activity in search for related materials and triggered intense studies of their properties. Indeed, very soon superconductivity (TC ~ 28-32 K) was also found in the series of related ternary systems (so-called 122 phases) such as CsxFe2-ySe2, RbxFe2-ySe2, (TlK)xFeySe2, (TlRb)xFeySe2 etc., which formed a new group of superconducting iron-based materials without toxic As. In this paper the recent progress in synthesis of 122-like iron-selenide systems and in experimental research of their properties is reviewed. Available theoretical data on electronic, magnetic, and elastic properties of this newest group of superconducting materials are also discussed.Comment: 44 pages, 27 figure

Limits on anomalous trilinear gauge boson couplings from WW, WZ and Wgamma production in pp-bar collisions at sqrt{s}=1.96 TeV

We present final searches of the anomalous gammaWW and ZWW trilinear gauge boson couplings from WW and WZ production using lepton plus dijet final states and a combination with results from Wgamma, WW, and WZ production with leptonic final states. The analyzed data correspond to up to 8.6/fb of integrated luminosity collected by the D0 detector in pp-bar collisions at sqrt{s}=1.96 TeV. We set the most stringent limits at a hadron collider to date assuming two different relations between the anomalous coupling parameters Delta\kappa_\gamma, lambda, and Delta g_1^Z for a cutoff energy scale Lambda=2 TeV. The combined 68% C.L. limits are -0.057<Delta\kappa_\gamma<0.154, -0.015<lambda<0.028, and -0.008<Delta g_1^Z<0.054 for the LEP parameterization, and -0.007<Delta\kappa<0.081 and -0.017<lambda<0.028 for the equal couplings parameterization. We also present the most stringent limits of the W boson magnetic dipole and electric quadrupole moments.Comment: 10 pages, 5 figures, submitted to PL

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02