Thema:

Measuring intact protons at the LHC: From the odderon discovery to the search for axion-like particles

Datum:

21.06.21

Uhrzeit:

16:15

Ort:

cyberspace

Vortragender:

Prof. Christophe Royon

University of Kansas

Inhalt:

In the first part of the talk, we will describe the odderon discovery by the TOTEM and D0 experiments. The analysis compares the p pbar elastic cross section as measured by the D0 Collaboration at a center-of-mass energy of 1.96 TeV to that in pp collisions as measured by the TOTEM Collaboration at 2.76, 7, 8, and 13 TeV. The two data sets disagree at the 3.4 sigma level and thus provide evidence for the t-channel exchange of a colorless, C-odd gluonic compound, also known as the odderon. We combine these results with a TOTEM analysis of the same C-odd exchange based on the total cross section and the ratio of the real to imaginary parts of the forward elastic strong interaction scattering amplitude in pp scattering, leading to a combined significance larger than 5 sigma. In a second part of the talk, we will describe the perspective on the search for quartic anomalous couplings and axion-like particles using tagged protons in the final state, leading to sensitivities to beyond standard model physics that improve by 2 to 3 orders of magnitude on the coupling. We will finish by decribing briefly the ultra fast silicon detectors for timing measurements as well as for medical and cosmic ray physics applications.

Ansprechpartner:

S. Schlichting

Thema:

Random matrices, spin glasses, and machine learning

Datum:

23.07.21

Uhrzeit:

16:15

Ort:

ZOOM/Konferenzschaltung

Vortragender:

Jon Keating

Oxford University

Inhalt:

I will describe some problems relating to machine learning and their connections to random matrix theory and spin glasses. These connections give a mathematical framework for understanding in qualitative terms the effectiveness of certain algorithms that are important in machine learning, but developing them into precise models remains a major challenge. I will reflect on the different roles played by models in computer science and physics, focussing on those involving random matrices.

Ansprechpartner:

G. Akemann

Thema:

Machine Learning for Thermodynamic Observables in Lattice Field Theories

Datum:

06.07.21

Uhrzeit:

14:15

Ort:

Online, via ZOOM

Vortragender:

Lena Funcke

Perimeter Institute, Ontario, Canada

Inhalt:

In this talk, I will discuss how applying machine learning techniques to lattice field theory is a promising route for solving problems where Markov Chain Monte Carlo (MCMC) methods are problematic. More specifically, I will show that deep generative models can be used to estimate thermodynamic observables like the free energy, which contrasts with existing MCMC-based methods that are limited to only estimate free energy differences. I will demonstrate the effectiveness of the proposed method for two-dimensional $\phi^4$ theory and compare it to MCMC-based methods in detailed numerical experiments.

Ansprechpartner:

G. Endrödi

Thema:

Der Groveralgorithmus auf einem universellen Quantencomputer - Nur eine Simulation oder tatsächlich umsetzbar?

Datum:

20.07.21

Uhrzeit:

10:15

Ort:

ZOOM / Konferenzschaltung

Vortragender:

Momme Hengstenberg

Universität Bielefeld

Inhalt:

Ansprechpartner:

Jürgen Schnack

Thema:

The Character Expansion in effective Theories for chiral Symmetry Breaking

Datum:

03.12.20

Uhrzeit:

16:30

Ort:

ZOOM / Konferenzschaltung

Vortragender:

Noah Aygün

Universität Bielefeld

Inhalt:

Ansprechpartner:

Gernot Akemann

Thema:

Schur expansion of random-matrix reproducing kernels

Datum:

21.07.21

Uhrzeit:

09:00

Ort:

ZOOM / Konferenzschaltung

Vortragender:

Miguel Tierz

Universidade de Lisboa

Inhalt:

We explain how to obtain expansions of reproducing kernels of the Christoffel-Darboux type in terms of Schur polynomials. The method is simply based on evaluations of averages of characteristic polynomials and Schur polynomials in random matrix ensembles. We explicitly compute some new Schur average and the ensuing expansion of the random matrix kernel. In addition to classical and q-deformed cases on the real line, we use extensions of Dotsenko-Fateev integrals to obtain expressions for kernels on the complex plane. We will comment also on a known interplay between Wronskians of Laguerre polynomials, Painlevé tau functions and conformal block expansions, now viewed in relation to the Schur expansion discussed.

Ansprechpartner:

Anas Rahman