Program winter term 2016/2017

Monday, Oktober 17, 2015, 4:15pm, Hörsaal 28 D 001

Dr. Christian Autermann (RWTH Aachen)

Search for Supersymmetry


The Large Hadron Collider at CERN has started to deliver proton-proton collisions in 2009 and since then led to a number of observations and precision measurements completing the Standard Model of particle physics. One widely observed highlight was the discovery of the Higgs boson, the last undiscovered particle of the Standard Model. While the Standard Model based on gauge symmetry is in nice agreement with all experimental observations, it is incomplete from a theoretical perspective: Open questions like for example the nature of the dark matter or the unification of forces remain unanswered. Therefore, the LHC experiments will focus in the coming data taking periods on searches for physics beyond the Standard Model, in particular on searches for supersymmetry. The motivation and features of supersymmetry and the utilized experimental analysis methods will be discussed.


Lutz Feld


Monday, November 07, 2016, 4:15pm, Hörsaal 28 D 001

Prof. Yoichi Ando (University of Cologne)

Topological Insulators and Superconductors


Topological insulators and superconductors are new quantum states of matter that are characterized by nontrivial topological structures of the Hilbert space. Recently, they attract a lot of attention because of the appearance of exotic quasiparticles such as spin-momentum-locked Dirac fermions or Majorana fermions on their edge/surface, which hold promise for various novel applications. In this talk, I will introduce the basics of those materials and present some of the key contributions we have made in this new frontier, such as the synthesis of bulk-insulating topological insulators, discovery of topological crystalline insulator, and the discovery of nematic topological superconductor.


Markus Morgenstern


Monday, November 21, 2016, 4:15pm, Hörsaal 28 D 001

Prof. Katia Parodi (LMU Munich)

State-of-the-art and physics research opportunities in ion beam therapy


The application of swift ions to radiation therapy is rapidly spreading worldwide, due to their favorable physical and biological properties for highly selective tumour treatment. To date over 50 (5 in Germany) ion therapy facilities are treating patients worldwide, predominantly with proton beams, and about the same amount is under construction or planning. 

This talk will review developments in accelerator technology, beam delivery and medical physics achieved in the last decades to enhance conformation of the radiation dose to complex-shaped tumour volumes. Emphasis will be given to the current state-of-the-art and remaining challenges of ion beam therapy, which open new opportunities
for a broad spectrum of ongoing physics-based research activities, spanning from computational modeling to detector developments and new imaging methods, towards full clinical exploitation of the ion advantages.


Achim Stahl


Monday, December 05, 2016, 4:15pm, Hörsaal 28 D 001

Dr. Christophe Grojean (DESY Hamburg)

Quo Vadis Higgs?


The search for the Higgs boson has occupied the particle physics community for the last 50 years. With the Higgs discovery in 2012, a new state of matter and a new dynamical principle have been revealed as essential building blocks of the fundamental laws of physics. High Energy Physics experiences a profound change in paradigm: What used to be the missing particle in the SM now quickly turns into a tool both to explore the manifestations of the SM and to possible venture into the physics landscape beyond. Higgs physics has now entered a precision era which will be extremely useful to guide future direct searches at the high-energy frontier at the LHC itself and at other future facilities. Higgs physics can also leave invaluable imprints in a stochastic gravitational wave background, or, via the coupling to an axion-like particle, bring the Universe into a self-organized critical phase.


Robert Harlander


Monday, December 19, 2016, 4:15pm, Hörsaal 28 D 001

Dr. Alexander Schmidt (Universität Hamburg)

Quest for new physics at the LHC


The experimental collaborations at the LHC are leaving no stone unturned in the quest for uncovering the remaining mysteries of particle physics.  Temporary excitement has been created by rather simple signatures (two photons) as well as complex final states with multiple boosted decay cascades. Despite the gigantic efforts by thousands of physicists no deviations from the predictions of the standard model of particle physics have been found yet. But the excitement is not over, the best is yet to come: with the huge high-luminosity dataset to be delivered by the LHC in the coming years, we will be able to follow new paths in constraining the standard model to an unprecedented precision.

In this talk the highlights of the search for new physics will be discussed, along with the experimental challenges. A special focus will be given to new analysis methods that facilitate the investigation of complex event topologies. Several fundamentally new ideas how to address the future challenges of data analysis at the LHC will be addressed.


Martin Erdmann


Monday, January 16, 2017, 4:15pm, Hörsaal 28 D 001

Prof. Andrei Lavrinenko (Technical University of Denmark)

Surface waves in photonics applications


We analyze surface electromagnetic waves supported at the interface between isotropic medium and effective anisotropic material that can be realized by alternating conductive and dielectrics layers or with more advanced two-dimensional mixing configuration. Depending on material dispersion properties such effective anisotropic material may exhibit also hyperbolic dispersion properties.  This configuration can host various types of surface waves and, therefore, can serve as a rich platform for applications in surface photonics. Most of these
surface waves are directional and as such their propagation can be effectively controlled by wavelength or material parameters tuning.


Dmitry Chigrin


Monday, January 30, 2017, 4:15pm, Hörsaal 28 D 001

Prof. Joachim Ullrich (Physikalisch-Technische Bundesanstalt Braunschweig)


Physical units based on fundamental constants - changing with time?


In 2018, on the occasion of the 25th meeting of the General Conference on Weights and Measures, CGPM, of the Metre Convention founded in 1875, it is envisaged to redefine the International System of Units (SI). In the future, as outlined by Max-Planck in his famous paper of 1900 postulating the “Planck constant”, it shall be based on
fundamental constants of nature, the “defining constants”: the velocity of light, the charge of the electron, the Boltzmann, Avogadro and the Planck constants, the Cs hyperfine clock transition and the luminous efficacy.

In the talk I will provide an overview on the progress, challenges and future perspectives of the new “Quantum SI” and discuss the question on whether or not the fundamental constants are indeed constant in time. New experiments are presently being devised, one of them based on next-generation optical clocks using transitions in highly charged ions that are read out via quantum-logic schemes. They bear the chance to trace potential changes in the fine structure constant α on the level of Δα/α ≈ 10 ^-20 per year.


Joerg Pretz