Leading Modes of the 3pi0 production in proton-proton collisions at incident proton momentum 3.35GeV/c

This work deals with the prompt pp-->pp3pi0 reaction where the 3pi0 do not origin from the decay of narrow resonances like \eta(547), \omega(782), \eta'(958). The reaction was measured for the proton beam momentum of 3.35GeV/c with the WASA-at-COSY detector setup. The dynamics of the reaction is investigated by Dalitz and Nyborg plots studies. The reaction is described by the model assuming simultaneous excitation of two baryon resonances \Delta(1232) and N*(1440) where resonances are identified by their unique decays topology on the missing mass of two protons MMpp dependent Dalitz and Nyborg plots. The ratio R=\Gamma(N*(1440)->N\pi\pi)/\Gamma(N*(1440)->\Delta(1232)\pi->N\pi\pi)= 0.039 +- 0.011(stat.) +- 0.008(sys.) is measured for the first time in a direct way. It shows that the {N*(1440)->\Delta(1232)\pi->N\pi\pi} decay is a leading mode of 3pi0 production. It is also shown that the MMpp is very sensitive to the structure of the spectral line shape of the N*(1440) resonance as well as on the interaction between the \Delta(1232) and N*(1440) resonances. The multipion spectroscopy - a precision tool to directly access the properties of baryon resonances is considered. The pp-->pp\eta(3pi0) reaction was also measured simultaneously. It is shown that the {\eta} production mechanism via N*(1535) is 43.4 +- 0.8(stat.) +- 2.0(sys.) of the total production, for the {\eta} momentum in the CM system q_\eta^CM=0.45-0.7GeV/c. First time momentum dependence of the {\eta} angular distribution is seen, the strongest effect is observed for the cos(\theta_\eta^CM) distribution.Comment: PhD Thesis prepared at the Nuclear Physics Department of the Jagiellonian University, Cracow, Poland, 201

Physics of EtaPrime->Pi+Pi-Eta and EtaPrime->Pi+Pi-Pi0 decays

The article describes experimental status of EtaPrime->Pi+Pi-Eta and EtaPrime->Pi+Pi-Pi0 decays. A theoretical framework used for description of the decays mechanism is also reviewed. The possibilities for the measurements with WASA-at-COSY are mentioned.Comment: Proceedings from Symposium on Meson Physics at COSY-11 and WASA-at-COSY, Cracow, 17-22 June 200

Nanostructure phase and interface engineering via controlled Au self-assembly on GaAs(001) surface

We have investigated the temperature-dependent morphology and composition changes occurring during a controlled self-assembling of thin Au film on the Gallium arsenide (001) surface utilizing electron microscopy at nano and atomic levels. It has been found that the deposition of 2 ML of Au at a substrate temperature lower than 798 K leads to the formation of pure Au nanoislands. For the deposition at a substrate temperature of about 798 K the nanostructures of the stoichiometric AuGa phase were/had been grown. Gold deposition at higher substrate temperatures results in the formation of octagonal nanostructures composed of an AuGa2 alloy. We have proved that the temperature-controlled efficiency of Au-induced etching-like of the GaAs substrate follows in a layer-by-layer manner leading to the enrichment of the substrate surface in gallium. The excess Ga together with Au forms liquid droplets which, while cooling the sample to room temperature, crystallize therein developing crystalline nanostructures of atomically-sharp interfaces with the substrate. The minimal stable cluster of 3 atoms and the activation energy for the surface diffusion Ed=0.816+-0.038eV was determined. We show that by changing the temperature of the self-assembling process one can control the phase, interface and the size of the nanostructures formed

Into the Origin of Electrical Conductivity for the Metal-Semiconductor Junction at the Atomic Level

The metal-semiconductor (M-S) junction based devices are commonly used in all sorts of electronic devices. Their electrical properties are defined by the metallic phase properties with a respect to the semiconductor used. Here we make an in-depth survey on the origin of the M-S junction at the atomic scale by studying the properties of the AuIn2 nanoelectrodes formed on the InP(001) surface by the in situ electrical measurements in combination with a detailed investigation of atomically resolved structure supported by the first-principle calculations of its local electrical properties. We have found that a different crystallographic orientation of the same metallic phase with a respect to the semiconductor structure influences strongly the M-S junction rectifying properties by subtle change of the metal Fermi level and influencing the band edge moving at the interface. This ultimately changes conductivity regime between Ohmic and Schottky type. The effect of crystallographic orientation has to be taken into account in the engineering of the M-S junction-based electronic devices

Probing the electronic transport on the reconstructed Au/Ge(001) surface

By using scanning tunnelling potentiometry we characterized the lateral variation of the electrochemical potential $\mu _{ec}$ on the gold-induced Ge(001)-c(8 × 2)-Au surface reconstruction while a lateral current flows through the sample. On the reconstruction and across domain boundaries we find that $\mu _{ec}$ shows a constant gradient as a function of the position between the contacts. In addition, nanoscale Au clusters on the surface do not show an electronic coupling to the gold-induced surface reconstruction. In combination with high resolution scanning electron microscopy and transmission electron microscopy, we conclude that an additional transport channel buried about 2 nm underneath the surface represents a major transport channel for electrons

Workshop on Digital Image Processing of SPM(AFM,SEM) data using ImageJ and Gwyddion

<p><strong>Workshop on Digital Image Processing of SPM(AFM,SEM) data using ImageJ and Gwyddion</strong></p> <p> </p> <p>Marian Smoluchowski Institute of Physics Jagiellonian University Krakow Poland 12.05.2016</p> <p>Organized by Dr Benedykt R. Jany</p> <p> </p> <p>Examples and Exercises</p> <p> </p> <p>The free software could be downloaded from:</p> <p>ImageJ/FIJI </p> <p>http://fiji.sc/</p> <p> </p> <p>Gwyddion</p> <p>http://gwyddion.net/</p> <p> </p> <p>LibreOffice</p> <p>https://www.libreoffice.org/</p

On the possibility of using arc plasma melting technique in preparation of transparent yttria ceramics

A state-of-the-art fabrication of Y2O3 transparent ceramic by arc plasma synthesis using commercial micron-size powders is reported. The morphological observations of the surface by scanning electron microscope shows that a dense microstructure can be obtained. Arc melted samples are made of a white core and transparent layer. X-ray diffraction studies and also Raman spectroscopy confirm that only one phase occurred in the core and in the transparent layer, and that the physicochemical difference exists. The obtained Y2O3 shell ceramics have pores but also relative low absorbance in the VIS-NIR region after double side polishing. The optical band gap and the refractive index are reported. It is concluded that arc plasma melting allows obtaining quickly (10 minutes) dense and highly transparent polycrystalline samples, especially in the VIS-IR spectral region