Research Articles (Physics)

 

Recent Submissions

  • Spectroscopy of low lying states in 136Cs 

    Rebeiro, B.; Triambak, S.; Lindsay, R.; Adsley, P.; Burbadge, C.; Ball, G.; Bildstein, V.; Faestermann, T.; Garrett, P. E.; Hertenberger, R.; Radich, A.; Rand, E.; Varela, A.; Wirth, H.-F. (IOP Publishing, 2016)
    The low-lying excited states in 136Cs relevant to the double beta decay of 136Xe were studied via a 138Ba(d, α)136Cs transfer reaction with a high resolution magnetic spectrometer. Preliminary results from the experiment ...

  • Distorted-wave Born approximation study of the 11Li(p,t) 9Li reaction 

    Cowley, A. A. (IOP Publishing, 2016)
    The reaction 11Li(p,t) 9Li(gs) at an incident energy of 4 MeV is treated in terms of a simplistic distorted-wave Born approximation transfer. The halo neutrons involved in the reaction are treated as a di-neutron cluster ...

  • Diffusions conditioned on occupation measures 

    Angeletti, Florian; Touchette, Hugo (AIP, 2016-02)
    A Markov process fluctuating away from its typical behavior can be represented in the long-time limit by another Markov process, called the effective or driven process, having the same stationary states as the original ...

  • An overview of the first decade of PollyNET : an emerging network of automated Raman-polarization lidars for continuous aerosol profiling 

    Baars, Holger; Kanitz, Thomas; Engelmann, Ronny; Althausen, Dietrich; Heese, Birgit; Komppula, Mika; Preißler, Jana; Tesche, Matthias; Ansmann, Albert; Wandinger, Ulla; Lim, Jae-Hyun; Ahn, Joon Young; Stachlewska, Iwona S.; Amiridis, Vassilis; Marinou, Eleni; Seifert, Patric; Hofer, Julian; Skupin, Annett; Schneider, Florian; Bohlmann, Stephanie; Foth, Andreas; Bley, Sebastian; Pfüller, Anne; Giannakaki, Eleni; Lihavainen, Heikki; Viisanen, Yrjo; Hooda, Rakesh Kumar; Pereira, Sergio Nepomuceno; Bortoli, Daniele; Wagner, Frank; Mattis, Ina; Janicka, Lucja; Markowicz, Krzysztof M.; Achtert, Peggy; Artaxo, Paulo; Pauliquevis, Theotonio; Souza, Rodrigo A. F.; Sharma, Ved Prakesh; Van Zyl, Pieter Gideon; Beukes, Johan Paul; Sun, Junying; Rohwer, Erich G.; Deng, Ruru; Mamouri, Rodanthi-Elisavet; Zamorano, Felix (Copernicus Publications on behalf of the European Geosciences Union, 2016)
    The paper gives an overview of the observations on four continents and two research vessels obtained with eight Polly systems. The specific aerosol types at these locations (mineral dust, smoke, dust-smoke and other dusty ...

  • Heavy baryons with strangeness in a soliton model 

    Blanckenberg, J. P.; Weigel, H. (Elsevier, 2015-09)
    We present results from a chiral soliton model calculation for the spectrum of baryons with a single heavy quark (charm or bottom) and non-zero strangeness. We treat the strange components within a three flavor collective ...

  • Galactic production of 138La : Impact of 138,139La statistical properties 

    Kheswa, B. V.; Wiedeking, M.; Giacoppo, F.; Goriely, S.; Guttormsen, M.; Larsen, A. C.; Bello Garrote, F. L.; Eriksen, T. K.; Gorgen, A.; Hagen, T. W.; Koehler, P. E.; Klintefjord, M.; Nyhus, H. T.; Papka, P.; Renstrom, T.; Rose, S.; Sahin, E.; Siem, S.; Tornyi, T. (Elsevier, 2015)
    The γ-ray strength functions and nuclear level densities of 138La and 139La have been measured below the neutron separation energies. These new data were used to calculate astrophysical Maxwellian-averaged (n, γ) cross-sections ...

  • Process tomography via sequential measurements on a single quantum system 

    Bassa, Humairah; Goyal, Sandeep K.; Choudhary, Sujit K.; Uys, Hermann; Diosi, Lajos; Konrad, Thomas (American Physical Society, 2015-09-03)
    We utilize a discrete (sequential) measurement protocol to investigate quantum process tomography of a single two-level quantum system, with an unknown initial state, undergoing Rabi oscillations. The ignorance of ...

  • Interplay of soundcone and supersonic propagation in lattice models with power law interactions 

    Storch, David-Maximilian; Van den Worm, Mauritz; Kastner, Michael (Bristol : IOP Publishing, 2015-06-16)
    Westudy the spreading of correlations and other physical quantities in quantum lattice models with interactions or hopping decaying like r−α with the distance r.Our focus is on exponents α between 0 and 6, where the ...

  • Higher-order interference and single-system postulates characterizing quantum theory 

    Barnum, Howard; Muller, Markus P.; Ududec, Cozmin (Institute of Physics, 2014-12-10)
    We present a new characterization of quantum theory in terms of simple physical principles that is different from previous ones in two important respects: first, it only refers to properties of single systems without any ...

  • Exchange-induced crystallization of soft-core bosons 

    Cinti, Fabio; Boninsegni, Massimo; Pohl, Thomas (Institute of Physics, 2014-03-28)
    We study the phase diagram of a two-dimensional assembly of bosons interacting via a soft-core repulsive pair potential of varying strength, and compare it to that of the equivalent system in which particles are regarded ...

  • Ultrafast dynamics of excitons in tetracene single crystals 

    Birech, Zephania; Schwoerer, Markus; Schmeiler, Teresa; Pflaum, Jens; Schwoerer, Heinrich (AIP Publishing LLC, 2014-03-18)
    Ultrafast exciton dynamics in free standing 200 nm thin tetracene single crystals were studied at room temperature by femtosecond transient absorption spectroscopy in the visible spectral range. The complex spectrally ...

  • White light wavefront control with a spatial light modulator 

    Dirk-Mathys, Spangenberg; Dudley, Angela; Neethling, Pieter H.; Rohwer, Erich G.; Forbes, Andrew (Optical Society of America, 2014-05)
    Spatial light modulators are ubiquitous tools for wavefront control and laser beam shaping but have traditionally been used with monochromatic sources due to the inherent wavelength dependence of the calibration process ...

  • Nonperturbative flow equations from running expectation values 

    Scholtz, F. G.; Bartlett, Bruce H.; Geyer, H. B. (American Physical Society (APS), 2003-08)
    We show that Wegner’s flow equations, as recently discussed in the Lipkin model, can be solved selfconsistently. This leads to a nonlinear differential equation which fully determines the order parameter as a function ...

  • Influence of gas discharge parameters on emissions from a dielectric barrier discharge excited argon excimer lamp 

    Baricholo, Peter; Hlatywayo, Dumisani J.; Von Bergmann, Hubertus M.; Stehmann, Timo; Rohwer, Erick; Collier, Mike (ASSAF -- Academy of Science of South Africa, 2011-11)
    A dielectric barrier discharge excited neutral argon (Ar I) excimer lamp has been developed and characterised. The aim of this study was to develop an excimer lamp operating at atmospheric pressure that can replace mercury ...

  • Internet access constrains science development and training at South African universities 

    Slippers, Bernard; Majozi, Thokozani; Nelwamondo, Fulufhelo V.; Steenkamp, Christine M.; Van Heerden, Esta; Wright, Caradee Y. (Academy of Science of South Africa (ASSAf), 2011-09)
    As a group of young scientists whose future careers depend increasingly on access to Internet resources, we are extremely concerned by the apparent lack of understanding of the stranglehold that current approaches to ...

  • Femtosecond pump probe spectroscopy for the study of energy transfer of light-harvesting complexes from extractions of spinach leaves 

    Ombinda-Lemboumba, S.; Du Plessis, A.; Sparrow, R. W.; Molukanele, P.; Botha, L. R.; Rohwer, E. G.; Steenkamp, C. M.; Van Rensburg, L. (Academy of Science of South Africa (ASSAf), 2009-10)
    Measurements of ultrafast transient processes, of temporal durations in the picosecond and femtosecond regime, are made possible by femtosecond pump probe transient absorption spectroscopy. Such an ultrafast pump probe ...

  • International astronomer Phil Charles meets the ire of the National Research Foundation 

    Bohm, Lothar (Academy of Science of South Africa (ASSAf), 2010-03)
    Recent weeks have seen an embarrassing display of heavy-handed National Research Foundation (NRF) management in connection with the Square Kilometer Array (SKA) project – a new $2 billion radio astronomy facility to be ...