Calendar of Physics Talks Vienna

Measurements for nuclear safety and waste minimization
Speaker:Dr. Arjan Plompen (E-141)
Date: Mon, 30.03.2009
Time: 16:00
Duration: 60 min
Location:Sem. 134A, Turm B, 5. OG

Vienna Theory Lunch Club - Antimatter does matter
Speaker:Bertalan Juhasz (SMI)
Abstract:Every particle in Nature has an antimatter counterpart, a kind of "mirror" particle. According to the fundamental Charge-Parity-Time (CPT) symmetry, which seems to be valid in all physical processes, a particle and its antiparticle should have identical properties like mass, charge, etc. (apart from a negative sign here and there). Moreover, our current understanding of particle physics suggests that matter and antimatter should always be created in equal amounts - either in laboratories now or during the Big Bang back then. However, our Universe seems to be made of matter only; there are no antigalaxies with antistars and antiplanets. One possible explanation to this apparent asymmetry is CPT violation, which would result in a non-equality of the properties of a particle and its antiparticle. The goal of the ASACUSA collaboration at CERN (Geneva, Switzerland) is to study the properties of antiproton, the antimatter counterpart of proton, and thus search for a violation of CPT symmetry. The first part of the talk will focus on measurements on a unique exotic molecule, the antiprotonic helium, which consists of a helium nucleus, an antiproton, and an electron. The unusually long lifetime of this molecule enables us to measure some of its transition frequencies using laser spectroscopy, and extract values for the charge and mass of the antiproton. The second part of the talk will explain a planned experiment to measure the ground-state hyperfine splitting of antihydrogen using an atomic beamline and microwave spectroscopy. According to some theoretical models, the hyperfine splitting is particularly sensitive to CPT violating effects.
Overview lunch club
Date: Tue, 31.03.2009
Time: 12:30
Duration: 60 min
Location:University of Vienna, Boltzmanngasse 5, 5th Floor, Large Seminar Room
Contact:Max Attems, Daniel Grumiller, Beatrix Hiesmayr

Fast atom diffraction on crystal surfaces
Speaker:Dipl.-Ing. Florian Aigner (TU Wien, Institut für Theoretische Physik)
Abstract:Diffraction of particles scattered at surfaces was among the key experiments establishing the quantum wave nature of matter. Atoms being diffracted at crystal surfaces exhibit intriguing diffraction patterns, closely related to those visible in double-slit experiments, which have been carried out using particles as heavy as fullerenes. Scattering of keV atoms at surfaces has recently been shown to be a powerful tool to investigate the structure of surfaces. Even in environments which would strongly suggest the dominance of decohering effects (hot surfaces, phonon vibrations) quantum coherent scattering patterns remain visible. This is especially remarkable, as the de Broglie wavelength of scattered atoms in the keV range is as low as a few picometers. F. Aigner et al. Phys.Rev.Lett. 101 (2008) 253201
Date: Tue, 31.03.2009
Time: 16:00
Location:Technische Universität Wien, Institut für Allgemeine Physik, Seminarraum 134A, Turm B (gelbe Leitfarbe), 5. OG, 1040 Wien, Wiedner Hauptstraße 8-10
Contact:Univ.Prof. Dr. Friedrich Aumayr

Holography in three and two dimensions
Speaker:Daniel Grumiller (Institute for Theoretical Physics, Vienna University of Technology)
Abstract:In this review lecture I construct in detail the holographic counterterm in AdS_3 and give some applications of AdS_3/CFT_2.
Date: Thu, 02.04.2009
Time: 14:15
Duration: 90 min
Location:Seminar room e136, Institute for Theoretical Physics, Vienna University of Technology, Wiedner Hauptstr. 8-10/136
Contact:Daniel Grumiller, Anton Rebhan

Attosecond Spectroscopy in Condensed Matter
Speaker:Prof. Dr. Reinhard Kienberger, Technische Universität München (ADLIS Seminar)
Date: Fri, 03.04.2009
Time: 14:00
Duration: 60 min
Location:Seminarraum CBEG02, Institut f. Photonik, Gußhausstr. 27
Contact:Heike Höller, SFB ADLIS Sekretariat, Tel: 58801 13625