Mr
René Sondenheimer
(FSU Jena)
22/02/2016, 16:45
We reanalyze the conventional arguments that relate a lower bound for the Higgs mass with vacuum stability in the framework of the functional renormalization group as well as in the light of exact results for the regularized fermion determinant. In both cases, we find no indication for vacuum instability nor metastability induced by top fluctuations if the cutoff is kept finite but arbitrary...
Mr
Dennis Loose
(TU Dortmund)
22/02/2016, 17:05
Experimental findings in semileptonic B decays by LHCb, Belle and BaBar hint at a possible violation of lepton universality. We investigate an explanation of this anomaly within leptoquark scenarios and point out correlations which arise from flavor symmetries that are known to be capable of describing the observed mixing of quarks and leptons.
Dr
Nicolai Christiansen
(Institute for Theoretical Physics, Heidelberg University)
22/02/2016, 17:25
I investigate the ultraviolet behaviour of quantum gravity within a functional renormalization
group approach. In particular, the scale- and momentum-dependence of the graviton propagator and the graviton three-point function are studied and the fixed point structure of the theory is analyzed.
Moreover, a novel locality property as an essential feature of a well-defined renormalization group...
Dr
Martin Schnabl
(Institute of Physics AS CR)
22/02/2016, 19:00
I will review the subject of topological defects in 2d CFT and discuss the novel aspects which arise in presence of boundaries. I will mention applications to open string field theory.
Mr
Tomotaka Kitamura
(Waseda University)
22/02/2016, 19:20
I studied the equivalence between tree unitarity and renormalizability in Lifshitz scalar theory. Tree-level unitarity and renormalizability are believed to be equivalent in field theories. No counter-example is known in relativistic field theories. However, the question whether the equivalence holds true for more generic field theories, such as non-relativistic theories is obscure. In my...
Mr
Denis Karateev
(SISSA)
22/02/2016, 19:40
In this short talk I will briefly summarise non-perturbative non-lagrangian formulation of CFTs and the philosophy of conformal bootstrap. I will then focus on 4D CFTs and discuss 3- and 4- point functions of operators with arbitrary spin: their computation, importance and future applications for conformal bootstrap.
Dr
Roman Gold
(University of Maryland)
23/02/2016, 16:45
Dr
Markus Huber
(University of Graz)
23/02/2016, 17:05
Functional equations like the functional renormalization group, Dyson-Schwinger equations or n-PI methods are useful tools which provide insight into the non-perturbative regime of quantum field theories. The basic objects are Green functions which can be calculated non-perturbatively. However, while the underlying equations are exact, approximations have to be introduced for the actual...
Dr
Mario Mitter
(University of Heidelberg)
23/02/2016, 17:25
We investigate SU(3)-Yang-Mills theory in a systematic vertex expansion scheme for the effective action. Particular focus is put on the dynamical creation of the gluon mass gap at non-perturbative momenta and the consistent treatment of quadratic divergences. The gluon and ghost propagators as well as the momentum-dependent ghost-gluon, three-gluon and four-gluon vertices are calculated...
Prof.
Gudrun Hiller
(TU Dortmund)
23/02/2016, 18:00
Flavor physics is highly sensitive to beyond the standard model (BSM) physics and vice versa.
In this talk we demonstrate this explicitly in the example of bottom-up leptoquark extensions of the Standard Model.
Recent anomalies in rare B-meson decays into leptons hinting at lepton non-unversality are addressed.
The talk is based on recent works arxiv:1408.1627, 1503.01084 and 1510.00311, all hep-ph.
Mr
Andrew Bond
(University of Sussex)
23/02/2016, 18:20
Renormalisation group flow of perturbative field theories
Prof.
Axel Maas
(University of Graz)
23/02/2016, 18:40
Experimentally observable particles require a gauge-invariant description. In non-Abelian gauge theories this implies that only composite operators, and thus bound states, can be physical.
Though bound states are genuine non-perturbative objects, the Froehlich-Morcchio-Strocchi mechanism nonetheless provides a possibility to determine the masses of Higgs, W, and Z using perturbation...
Mr
Jacopo Fumagalli
(NIKHEF)
24/02/2016, 19:20
The predictions of (Standard model) Higgs inflation are in excellent agreement with the Planck data, without needing new particles beyond the ones we know. Nevertheless, introducing some threshold corrections is demanded by the consistency of the theory. This raises the question: how sensitive the CMB predictions are to the UV completion? I will show that as long as the UV corrections do not...
Mr
Héctor Ramírez Rodríguez
(IFIC - University of Valencia)
24/02/2016, 19:40
Inflation provides the most theoretically attractive and observationally successful cosmological scenario able to generate the initial conditions of our universe. From the theoretical viewpoint, this picture is usually understood as the dynamics of a single new scalar degree of freedom, the inflaton, minimally coupled to gravity. However, generally the inflaton is expected to have a nonminimal...
Dr
Sergey Cherkas
(Institute for Nuclear Problems, Belarusian State University)
It is shown, that initial conditions in the quasi-Heisenberg quantization scheme can be set at an initial cosmological singularity per se. This possibility is provided by finiteness of some quantities, namely momentums of the dynamical variables, at a singularity, in spite of infinity of the dynamical variables themselves. The uncertainty principle allows avoiding a necessity to set values of...
Dr
Matthias Ihl
(Centro de Física do Porto, FCUP, Universidade do Porto)
Holographic Anyons and the virial expansion. Some recent progress on strongly coupled anyons will be discussed.
