Browsing Τμήμα Φυσικής / Department of Physics by Title

Now showing items 21-40 of 1410

    • Article  

      Analytic Q ball solutions in a parabolic-type potential 

      Theodorakis, Stavros (2000)
      We introduce a piecewise parabolic potential for a complex scalar field and we show that it admits stable Q ball solutions. These solutions can be found analytically, unlike the case of polynomial potentials. We find stable ...
    • Article  

      Analytic solutions for the evolution of domain walls 

      Theodorakis, Stavros (1999)
      We introduce an unusual asymmetric double well potential, a piecewise parabolic one, and we show that the solutions for the evolution of its domain walls can be found analytically, in contrast with the case of the standard ...
    • Article  

      Analytic vortex solutions in an unusual Mexican-hat potential 

      Theodorakis, Stavros (1997)
      We introduce an unusual Mexican-hat potential, a piecewise parabolic one, and we show that its vortex solutions can be found analytically, in contrast to the case of the standard |Ψ|4 field theory.
    • Article  

      Annealing Kinetics of Defects of Ion-Implanted and Furnace-Annealed Silicon Layers - Thermodynamic Approach 

      Christofides, Constantinos (1992)
      This article reviews some recent results concerning the effects of isochronal annealing and the attempts to model the kinetics of local reconstruction mechanisms of layers with different degrees of inhomogeneity such as ...
    • Article  

      Anomalous electronic conductance in quasicrystals 

      Roche, S.; Moulopoulos, Konstantinos (2000)
      Subtle quantum interference effects in one-dimensional quasicrystals are reported. Quite opposite to their metallic counterparts, quasiperiodic systems are shown to exhibit interesting variations of their conducting ...
    • Article  

      Antivortex domain walls observed in permalloy rings via magnetic force microscopy 

      Roy, P. E.; Lee, J. H.; Trypiniotis, Theodossis; Anderson, D.; Jones, G. A. C.; Tse, D.; Barnes, C. H. W. (2009)
      Magnetic domain walls in patterned permalloy ring elements of different widths and thicknesses have been probed by magnetic force microscopy and micromagnetic simulations. We report the experimental observation of antivortex ...
    • Book  

      Application of Fourier Transformation infrared spectroscopy to the characterization of the intermediate band solar cell optical transitions 

      Lopez, Nidia; Burhan, M.; Christofides, Constantinos; Farmer, Corrie; Diaz, P.; Antolin, Elisa; Canovas, E.; Stanley, C. R.; Marti, Antonio; Luque, Antonio (2017)
    • Article  

      Arbitrary mixture of two charged interacting particles in a magnetic Aharonov-Bohm ring: Persistent currents and Berry's phases 

      Kyriakou, Kyriaki; Moulopoulos, Konstantinos; Ghazaryan, A. V.; Djotyan, Anahit P. (2010)
      Aharonov-Bohm physics at the two-particle level is investigated for distinguishable interacting charged particles through the exact solution of a toy model with confined states. The effect of the inaccessible magnetic flux ...
    • Article  

      Arsenic implanted silicon by transport effect. Thermal annealing influence 

      Christofides, Constantinos; G Ghibaudo; H Jaouen (1987)
      A study of the effects of thermal annealing on the transport properties in arsenic implanted silicon films is reported. In particular, the sheet resistance and the Hall mobility obtained by the Van der Pauw method is ...
    • Conference Object  

      Aspects of string cosmology 

      Kounnas, Costas; Toumbas, Nicolaos K. (Trieste, SISSA: Proceedings of Science., 2013)
      We review recent progress in string cosmology, where string dualities are applied so as to obtain complete cosmological evolutions, free of any essential singularities. Two classes of models are analyzed. The first class ...
    • Article  

      Associate K0 production in p+p collisions at 3.5 GeV: The role of Δ(1232)++ 

      Krücken, R.; Agakishiev, G.; Arnold, O.; Belver, D.; Belyaev, A.; Berger-Chen, J. C.; Blanco, A.; Böhmer, M.; Boyard, J. L.; Cabanelas, Pablo; Chernenko, S.; Dybczak, A.; Epple, E.; Fabbietti, L.; Fateev, O.; Finocchiaro, P.; Fonte, P.; Friese, J.; Fröhlich, I.; Galatyuk, T.; Garzón, J. A.; Gernhäuser, R.; Göbel, K.; Golubeva, M.; González-Díaz, D.; Guber, F.; Gumberidze, M.; Heinz, T.; Hennino, T.; Holzmann, R.; Ierusalimov, A.; Iori, I.; Ivashkin, A.; Jurkovic, M.; Kämpfer, B.; Karavicheva, T.; Koenig, I.; Koenig, W.; Kolb, B. W.; Korcyl, G.; Kornakov, G.; Kotte, R.; Krása, Antonín; Krizek, F.; Kuc, H.; Kühn, W.; Kugler, A.; Kunz, T.; Kurepin, A.; Ladygin, V.; Lalik, R.; Lapidus, K.; Lebedev, A.; Lopes, L.; Lorenz, M.; Maier, L.; Mangiarotti, A.; Markert, J.; Metag, V.; Michel, J.; Müntz, C.; Münzer, R.; Naumann, L.; Pachmayer, Y. C.; Palka, M.; Parpottas, Yiannis; Pechenov, V.; Pechenova, O.; Pietraszko, J.; Przygoda, W.; Ramstein, B.; Reshetin, A.; Rustamov, A.; Sadovsky, A.; Salabura, P.; Schmah, A.; Schwab, E.; Siebenson, J.; Sobolev, Y. G.; Spruck, B.; Ströbele, H.; Stroth, J.; Sturm, C.; Tarantola, A.; Teilab, K.; Tlusty, P.; Traxler, M.; Tsertos, Haralambos; Vasiliev, T.; Wagner, V.; Weber, M.; Wendisch, C.; Wüstenfeld, J.; Yurevich, S.; Zanevsky, Y. (2014)
      An exclusive analysis of the four-body final states Λ+p+π++K0 and Σ0+p+π++K0 measured with HADES for p+p collisions at a beam kinetic energy of 3.5 GeV is presented. The analysis uses various phase space variables, such ...
    • Article  

      Asymptotic scaling corrections in QCD with Wilson fermions from the 3-loop average plaquette 

      Allés, B.; Feo, A.; Panagopoulos, Haralambos G. (1998)
      We calculate the 3-loop perturbative expansion of the average plaquette in lattice QCD with Nf massive Wilson fermions and gauge group SU(N). The corrections to asymptotic scaling in the corresponding energy scheme are ...
    • Article  

      Autonomous Photovoltaic Power-System Or Connection with Electrical Grid - a Preliminary Feasibility Study for Small and Isolated Communities 

      Christofides, Constantinos (1989)
    • Article  

      Axial charges of hyperons and charmed baryons using Nf=2+1+1 twisted mass fermions 

      Alexandrou, Constantia; Hadjiyiannakou, Kyriakos; Kallidonis, Christos (2016)
      The axial couplings of the low lying baryons are evaluated using a total of five ensembles of dynamical twisted mass fermion gauge configurations. The simulations are performed using the Iwasaki gauge action and two ...
    • Article  

      Axial nucleon and nucleon to Δ form factors and the Goldberger-Treiman relations from lattice QCD 

      Alexandrou, Constantia; Koutsou, Giannis; Leontiou, Theodoros; Negele, J. W.; Tsapalis, Antonios (2007)
      We evaluate the nucleon axial form factor, GA(q2), and induced pseudoscalar form factor, Gp(q2), as well as the pion-nucleon form factor, GπNN(q2), in lattice QCD. We also evaluate the corresponding nucleon to Δ transition ...
    • Article  

      Axial nucleon form factors from lattice QCD 

      Alexandrou, Constantia; Brinet, M.; Carbonell, J.; Constantinou, Martha; Harraud, P. A.; Guichon, P.; Jansen, K.; Korzec, T.; Papinutto, M. (2011)
      We present results on the nucleon axial form factors within lattice QCD using two flavors of degenerate twisted mass fermions. Volume effects are examined using simulations at two volumes of spatial length L=2.1fm and ...
    • Article  

      B-meson properties from lattice QCD 

      Alexandrou, Constantia; Jegerlehner, F.; Güsken, S.; Schilling, K.; Sommer, R. (1991)
      A high statistics computation of the decay constant f{hook}B is presented to study scaling and finite size effects. Smooth wave functions for the B-meson allow to suppress excited state contributions effectively. We observe ...
    • Article  

      Baryon resonance production and dielectron decays in proton-proton collisions at 3.5 GeV 

      Krücken, R.; Agakishiev, G.; Bałanda, A.; Belver, D.; Belyaev, A.; Berger-Chen, J. C.; Blanco, A.; Böhmer, M.; Boyard, J. L.; Cabanelas, Pablo; Chernenko, S.; Dybczak, A.; Epple, E.; Fabbietti, L.; Fateev, O.; Finocchiaro, P.; Fonte, P.; Friese, J.; Fröhlich, I.; Galatyuk, T.; Garźon, J. A.; Gernhäuser, R.; Göbel, K.; Golubeva, M.; Gonźalez-D́iaz, D.; Guber, F.; Gumberidze, M.; Heinz, T.; Hennino, T.; Holzmann, R.; Ierusalimov, A.; Iori, I.; Ivashkin, A.; Jurkovic, M.; Kämpfer, B.; Karavicheva, T.; Koenig, I.; Koenig, W.; Kolb, B. W.; Kornakov, G.; Kotte, R.; Krása, Antonín; Krizek, F.; Kuc, H.; Kühn, W.; Kugler, A.; Kurepin, A.; Ladygin, V.; Lalik, R.; Lang, S.; Lapidus, K.; Lebedev, A.; Liu, T.; Lopes, L.; Lorenz, M.; Maier, L.; Mangiarott, A.; Markert, J.; Metag, V.; Michalska, B.; Miche, J.; M̈untz, C.; Naumann, L.; Pachmayer, Y. C.; Palka, M.; Parpottas, Yiannis; Pechenov, V.; Pechenova, O.; Pietraszko, J.; Przygoda, W.; Ramstein, B.; Reshetin, A.; Rustamov, A.; Sadovsky, A.; Salabura, P.; Schmah, A.; Schwab, E.; Siebenson, J.; Sobolev, Y. G.; Spataroh, S.; Spruck, B.; Str̈obele, H.; Stroth, J.; Sturm, C.; Tarantola, A.; Teilab, K.; Tlusty, P.; Traxler, M.; Trebacz, R.; Tsertos, Haralambos; Vasiliev, T.; Wagner, V.; Weber, M.; Wendisch, C.; Ẅustenfeld, J.; Yurevich, S.; Zanevsky, Y. (2014)
      We report on baryon resonance production and decay in proton-proton collisions at a kinetic energy of 3.5 GeV based on data measured with HADES. The exclusive channels pp → npπ+ and pp → ppπ0 as well as pp → ppe+e- are ...
    • Article  

      Baryon spectrum with Nf=2+1+1 twisted mass fermions 

      Alexandrou, Constantia; Drach, V.; Jansen, K.; Kallidonis, Christos; Koutsou, Giannis (2014)
      The masses of the low-lying baryons are evaluated using a total of ten ensembles of dynamical twisted mass fermion gauge configurations. The simulations are performed using two degenerate flavors of light quarks, and a ...
    • Article  

      Baryon structure from Lattice QCD 

      Alexandrou, Constantia (2009)
      We present recent lattice results on the baryon spectrum, nucleon electromagnetic and axial form factors, nucleon to Δ transition form factors as well as the Δ electromagnetic form factors. The masses of the low lying ...