Seminars SS 2021

Tuesday, July 20, 2021, 4:30pm (online)

Christoph Langenbruch (RWTH Aachen University)

Flavour anomalies in rare B decays



Recent measurements of rare b-hadron decays have shown tensions with SM predictions.

These tensions, known as the flavour anomalies, have appeared in measurements of branching fractions, angular analyses, and tests of lepton universality.

In this talk I will summarise the status of the flavour anomalies, concentrating on the latest measurements by the LHCb collaboration. 


Host: Jonathan Hermann




Tuesday, July 13, 2021, 4:30pm (zoom)

Tobias Hurth (Johannes Gutenberg Universität Mainz)

Semileptonic Penguins and the b to s Anomalies



I will discuss the new physics opportunities of exclusive and inclusive semileptonic penguin decays, including the so-called b > s anomalies. In the second part of the talk I will focus on the calculation of subleading contributions to the inclusive mode using soft-collinear effective theory.


Host: Michael Czakon




Tuesday, July 06, 2021, 4:30pm (zoom)

Ralph Assmann (DESY Hamburg)

New Particle Acceleration Methods for High Energy Physics



Accelerator science and technology has seen steep progress since 1927 when Wideröe demonstrated for the first time RF acceleration in Aachen. Colliders based on RF technology are today among the most complex and largest machines built by human mankind. At those facilities new particles and forces of nature have been discovered and human knowledge was advanced tremendously. However, practical limitations in size and cost limit progress in beam energy reach during recent years. New acceleration methods have been proposed in 1979 and provide 100-1000 times higher acceleration fields than RF accelerators. Those new schemes hold the promise of much more compact and cost-effective accelerators. The physics principle of those accelerators is explained and the present state of the art and future potential for particle physics are discussed. The EuPRAXIA project will be introduced. The EuPRAXIA facility is based on plasma accelerators and was just placed on the roadmap for future European research infrastructures.


Host: Lutz Feld




Tuesday, June 22, 2021, 4:30pm (zoom)

Stefan Hild (Maastricht University)

Status of Gravitational Waves Searches



The discoveries of gravitational waves from binary black holes and neutron stars has provided us with a stunning glimpse at an entirely new way to explore our universe. In order to discover new phenomena and better understand the constituents of the Cosmos and the forces driving it, it is vital to improve the sensitivity of future gravitational wave observatories. The planned Einstein Telescope (ET) will be the first one of an entirely new class of gravitational wave observatories, targeting to go beyond the fundamental limits of the current gravitational wave detectors. The talk will cover what new discoveries we can expect to achieve with ET. Also an overview of the design  and the technological challenges of ET will be given, as well as an update of the ET related activities in the Dutch-Belgium-German border region, one of two candidate sites for hosting the Einstein Telescope.


Host: Thomas Hebbeker




Tuesday, June 08, 2021, 4:30pm (online)

Frank Hartmann (Karlsruhe School of Elementary Particle and Astroparticle)

Overview of the LHC Upgrade for HL-LHC


Abstract: tbd


Host: Alexander Schmidt




Tuesday, May 11, 2021, 4:30pm (zoom)

Anke Biekötter (IPPP Durham)

Hunting New Physics in a Model-Independent Framework  



New physics at the TeV scale, if it exists, has evaded detection in resonance searches at the LHC so far. Instead, new physics  might manifest itself in small deviations in the couplings predicted by  the Standard Model. A versatile framework to describe small diversions  from the SM through higher-order interactions of the SM fields is given  by Standard Model Effective Field Theory (SMEFT).

In this seminar, I will give an introduction to the SMEFT and review in which ways dimension-six operators can influence LHC observables of the  electroweak sector. Moreover, I will give an overview of the current  status of global fit in the SMEFT framework.


Host: Michael Krämer




Tuesday, April 27, 2021, 4:30pm, (zoom)

Stefan Weinzierl - Johannes Gutenberg Universität Mainz

Modern Methods for Scattering Amplitudes



In this talk I will review recent developments in the field of scattering amplitudes.
I will introduce the concepts colour-kinematics duality, positive geometries and intersection theory.
Albeit these new methods provide alternative ways to compute scattering amplitudes, the main virtue lies in the fact that they connect (tree-level) scattering amplitudes in Yang-Mills theory and gravity.

Host: Robert Harlander