CPT

Calendar of Physics Talks Vienna

Anomalous and axial Z' contributions to g-2
Speaker:Pascal Anastasopoulos (HEPHY)
Abstract:In this talk, we will study the effects of an anomalous Z' boson on the anomalous magnetic moment of the muon (g-2), and especially the impact of its axial coupling. We mainly evaluate the negative contribution to (g-2) of such couplings at one-loop and look at the anomalous couplings generated at two loops. We find areas of the parameter space, where the anomalous contribution becomes comparable and even dominant compared to the one-loop contribution. We show that in such cases, the cutoff of the theory is sufficiently low, so that new charged fermions can be found in the next round of collider experiments.
Date: Tue, 17.01.2023
Time: 14:00
Duration: 60 min
Location:Sem.R. DB gelb 03 (Freihaus, TU Wien, Wiedner Hauptstrasse 8)
Contact:S. Fredenhagen, D. Grumiller, E. Battista, R. Ruzziconi

Precision Standard Model Phenomenology at N3LO and beyond
Speaker:Gherardo Vita (MIT)
Abstract:Collider experiments will achieve percent level precision measurements of several processes key to answer some of the most pressing questions of contemporary particle physics. In this talk I will show that the capability to predict and describe such observables at next-to-next-to-next-to-leading order (N3LO) in QCD perturbation theory is crucial to fully exploit these experimental measurements. I will describe how to compute differential distributions via EFT-based subtraction methods and illustrate the calculation of the N3LO TMD and N-jettiness beam functions.These constitute the last missing ingredients for extending these techniques to N3LO for processes such as Higgs production in gluon fusion and Drell-Yan and a key element for the application of these techniques toprocesseswith jets in the final state at this order.
Date: Tue, 17.01.2023
Time: 16:15
Duration: 60 min
Location:Fakultaet fuer Physik, Erwin Schroedinger-HS, Boltzmanngasse 5, 5. Stock
Contact:A. Hoang, M. Procura, A. Broggio

Instability of a massless scalar field confined in a perfectly reflecting spherical cavity
Speaker:M. Maliborski (Vienna)
Abstract:I will discuss a spherically symmetric gravitating model that exhibits turbulent dynamics, conjectured to be the core mechanism of instability of the anti-de Sitter solution. Using the resonant approximation, I will provide evidence that generic arbitrarily small initial perturbations of amplitude epsilon lead to a black hole formation on the timescale 1/epsilon^2. Furthermore, I will argue that the perturbative approximation remains valid up to apparent horizon formation.
Date: Thu, 19.01.2023
Time: 15:15
Duration: 60 min
Location:Seminarraum A, Waehringer Strasse 17, 2. Stock
Contact:P. Chrusciel, D. Fajman

Algebra of symmetry in BF-like models and observables
Speaker:Christophe Goeller (Ludwig-Maximilians University Munich)
Abstract:In this talk, I will discuss the construction of the boundary symmetry algebra for BF-like theories in 3D and 4D. In the 3D case, the theory corresponds to (an extension of) 3D gravity allowing for a source of curvature and torsion. I will show how the study of the current algebra and its associated Sugawara construction allows for two notions of quadratic charges (the usual diffeomorphism and its "dual") independently of boundary conditions. I will discuss their resulting algebra and its relation with the usual construction of the asymptotic boundary algebra. In the 4D case, a similar yet fundamentally different construction is possible, similarly resulting in multiple quadratic charges. I will discuss their constructions and their possible relations to 4D gravity.
Date: Thu, 19.01.2023
Time: 17:00
Duration: 60 min
Location:Freihaus, Sem.R. DB gelb 10
Contact:Romain Ruzziconi, Daniel Grumiller, Iva Lovrekovic

Sub-Leading and Super-Leading Logarithms in Jet Processes
Speaker:Thomas Becher (Albert Einstein Center for Fundamental Physics, University of Bern)
Abstract:Jet cross sections at high-energy colliders exhibit intricate patterns of logarithmically enhanced higher-order corrections. In particular, so-called non-global logarithms emerge from soft radiation emitted off energetic partons inside jets. While this is a single-logarithmic effect at lepton colliders, at hadron colliders phase factors in the amplitudes lead to double-logarithmic corrections starting at four-loop order. In my talk I’ll first explain the resummation of non-global logarithms at lepton colliders, where techniques for the resummation of sub-leading logarithms are now available. I’ll then explain the origin of the ``super-leading’’ double logarithms at hadron colliders and discuss their resummation.
Date: Fri, 20.01.2023
Time: 16:15
Duration: 60 min
Location:Fakultaet fuer Physik, Erwin Schroedinger-HS, Boltzmanngasse 5, 5. Stock
Contact:A. Hoang, M. Procura, A. Broggio