Ss2025
Tuesday seminars start at 15:15. Friday seminars start at 14:15.
Unless otherwise stated, the seminars will be held in PHY 5.1.34A.
Fri, 25th Apr
- Time: 14:15
- Speaker: Dennis Völkl (Master Vortrag)
- Invited by: A. Schäfer (and Franziska Görtler (Universität Bergen))
- Title: Hierarchical Cell Type Deconvolution
Tue, 29th Apr
- Time: 15:15
- Speaker: Anton Olsson (KIT, Universität Karlsruhe)
- Invited by: A. von Manteuffel
- Title: Interpolating Amplitudes
Abstract
While the calculation of scattering amplitudes at higher orders in perturbation theory has reached a high degree of maturity, their usage to produce physical predictions within Monte Carlo programs is often hampered by the slow evaluation of the multi-loop amplitudes. As a remedy, interpolation frameworks have been successfully used in lower dimensions, but for higher-dimensional problems standard methods fail. In this seminar I will show how interpolation and error estimation can be improved when applied in the context of amplitudes. I will also give an overview of approximation methods we have investigated that scale well with respect to dimension, and show their performance on amplitudes entering into ttH production. Finally, I will briefly comment on practical aspects of constructing and including amplitude grids in Monte Carlo programs.Fri, 2nd May
- Time: 14:15
- Speaker: Bakul Agarwal (University of Edinburgh)
- Invited by: A. von Manteuffel
- Title: Complete Next-to-Leading Order QCD Corrections to ZZ Production in Gluon Fusion
Abstract
We present our results for complete next-to-leading order QCD corrections to ZZ production through gluon fusion. We combine the two-loop amplitudes with top quark mass dependence calculated numerically in a previous work with the analytic forms of massless, Higgs-mediated, and one-loop factorisable diagrams to obtain complete virtual corrections. We show that the choice of IR subtraction scheme used for virtuals has a significant impact on their size as well as required precision. We also present an estimate for the uncertainty due to the choice of top quark mass scheme.Fri, 9th May
- Time: 14:15
- Speaker: Dr. Johann Ostmeyer (Universität Bonn, HISKP)
- Invited by: M. Rodekamp
- Title: The Prony Generalised Eigenvalue Method for symmetric correlators
Abstract
The extraction of energy levels from Euclidean correlators is a common problem in lattice QCD and, more generally, Euclidean time simulations. There exists a multitude of mathematically equivalent methods (Prony, Lanczos, generalised pencil of function...) that guarantee optimal estimators of the lowest energy levels for noiseless data. Recently, significant progress has been made in increasing the robustness of these methods for noisy data. In this talk the main improvements will be highlighted. Moreover, difficulties arising specifically for symmetric correlators will be addressed and possible solutions (work in progress) presented.Fri, 23rd May
- Time: 14:15
- Speaker: Linus Götzfried (Master Vortrag)
- Invited by: A. v. Manteuffel
- Title: Analytical Results for Loop Integrals with Many Scales
Tue, 24th Jun
- Time: 15:15
- Speaker: Nico Voß (Master Vortrag)
- Invited by: T. Wettig
- Title: Optimisation of lattice Dirac operators for Pytorch
Fri, 4th Jul
- Time: 14:15
- Speaker: Philipp Erhardt (Bachelor Vortrag)
- Invited by: A. v. Manteuffel
- Title: The Massless and Massive Spinor Helicity Formalism
Fri, 11th Jul
- Time: 14:15
- Speaker: Christian Fischer (Universität Gießen)
- Invited by: G. Bali
- Title: Spectra and properties of conventional and exotic hadrons from functional methods
Abstract
We summarise recent theoretical results on the spectrum and properties of zero, two, three- and four-quark states obtained from functional QCD using Dyson-Schwinger and Bethe-Salpeter equations. We discuss properties of glueballs in Yang-Mills theory and prospects to study their properties in QCD. We discuss differences and similarities in the spectra of light and strange baryons and address the flavour dependence and the internal structure of four-quark states with open and hidden charm and bottom content.Tue, 15th Jul
- Time: 15:15
- Speaker: Tanishk Shrimal (I.M.Sc. Chennai)
- Invited by: S. Collins
- Title: Strange partner of Tcc tetraquark from lattice QCD
Fri, 18th Jul
Tag der Physik und Mathematik
Tue, 22nd Jul
- Time: 15:15
- Speaker: Jonna Koponen (Universität Wuppertal)
- Invited by: S. Collins
- Title: Muon g-2, lattice QCD and pion transition form factor
Abstract
The anomalous magnetic moment of the muon has, for over twenty years now, provided an enduring hint for new physics, in the form of tantalizing tensions between Standard Model (SM) theory and experiment. A lot of progress has been made lately, as the muon g-2 experiment in Fermilab announced the result of all six runs in June 2025. The experimental result is extremely precise, and the theory community is working hard to reach comparable precision. In this talk I will give an overview of the status of muon g-2, and then focus on how lattice QCD is helping in improving the SM theory prediction. In particular, I will describe a specific part of the calculation, namely the extraction of the pion transition form factor for $\pi \to \gamma \gamma$, and how that is related to the hadronic light-by-light contribution to muon g-2.Fri, 25th Jul
- Time: 14:15
- Speaker: Christian Kindler (Master Vortrag)
- Invited by: G. Bali
- Title: Nucleon Isovector Axial Charge and Form Factor from Lattice QCD
Tue, 9th Sep
!!!extra seminar!!!
- Time: 15:15
- Speaker: Debsubhra Chakraborty (TIFR Mumbai)
- Invited by: G. Bali
- Title: Light Nuclei Spectroscopy from Lattice QCD
Tue, 30th Sep
!!!extra seminar!!!
- Time: 15:15
- Speaker: Bhabani Sankar Tripathy (IMSc, Chennai)
- Invited by: C. Collins
- Title: Study of Doubly bottom and bottom-strange Tetraquark from Lattice QCD