"Theory of Particle Physics and Cosmology" Seminar
2017/2018 | 2018/2019 | 2019/2020 | 2020/2021 | 2021/2022 | 2022/2023 | 2023/2024
2018-06-14 (Thursday)
room 1.01, Pasteura 5 at 12:15 
Marek Karliner (Tel Aviv U.)The Social Life of Heavy Quarks
I will discuss recent developments regarding new types of hadronsinvolving heavy quarks: hadronic molecules, doubly heavy baryons,stable tetraquarks and others. I will also explain how the discovery ofthe doubly heavy baryon leads to quark-level analogue of nuclear fusion,with energy release per reaction an order of magnitude greater than inordinary fusion.
2018-06-07 (Thursday)
room 1.01, Pasteura 5 at 12:15
Luca Merlo (Universidad Autonoma de Madrid)Higgs effective field theories and phenomenological strategies
With the discovery of a scalar resonance at ATLAS and CMS, the understanding of the electroweak symmetry breaking sector seems a much closer goal. Theories of New Physics where the electroweak symmetry breaking occurs linearly describe different deviations from the SM predictions with respect to theories where the electroweak symmetry breaking is non-linearly realised. I will review and compare the effective Lagrangians of the linear and non-linear realisations, dubbed SMEFT and HEFT respectively, and discuss some phenomenological signals that may lead to disentangle between the two possibilities.
2018-05-24 (Thursday)
room 1.01, Pasteura 5 at 12:15
Piotr Korcyl (UJ)Exploring hadron structure functions using Lattice QCD
In my talk I will present an overview of recent efforts to estimate non-perturbatively proton and pion structure functions using Lattice QCD techniques which go beyond the computation of first few moments. In the second part I will describe progress of Regensburg Lattice QCD collaboration in estimating non-perturbatively the pion distribution amplitude.
2018-05-10 (Thursday)
room 1.01, Pasteura 5 at 12:15
Takeshi Kobayashi (SISSA)Cosmology with Light Scalars
The appearance of scalar fields with small masses is ubiquitous in physics beyond the Standard Model. In this talk I will describe how such light scalars can play important roles in cosmology, particularly in connection to the origin of the baryons, dark matter, and dark energy of our universe. With regard to the baryons, I will show that a light scalar, such as the QCD axion, can naturally induce baryogenesis. For dark matter, I will present cosmological constraints on scalar dark matter obtained from analyses of the Lyman-alpha forest and the cosmic microwave background. I will also present a novel scenario where dark energy emerges from scalar dark matter.
2018-04-26 (Thursday)
room 1.01, Pasteura 5 at 12:15
Stephane Lavignac (Saclay)Lepton flavour effects in scalar triplet leptogenesis
I will discuss the role of lepton flavour in scalar triplet leptogenesis,a mechanism for the generation of the baryon asymmetry of the Universe involving a heavy scalar triplet, which decays in a CP-violating way into leptons and antileptons. I will show in particular that the effects of the different lepton flavours can never be neglected, and that their proper description at high temperature requires flavour-covariant Boltzmann equations. The numerical impact of these lepton flavour effects on the predicted baryon asymmetry can be very significant in all temperature regimes, contrary to the standard leptogenesis scenario with heavy right-handed neutrinos.
2018-04-19 (Thursday)
room 1.01, Pasteura 5 at 12:15
Chunshan Lin (IFT UW)Is GR unique?
Probably not. I will introduce some different gravity theories which are asgood as GR in the sense that all of constraints are first class and thereforea graviton has only 2 polarisations and the structure of the theory at lowenergies is thus expected to be stable against quantum corrections.
2018-04-12 (Thursday)
room 1.01, Pasteura 5 at 12:15
Benjamin Allanach (Cambridge University)The Case for Future Hadron Colliders From B→K*μ+μ- Decays
Recent measurements in B→K*μ+μ- decays are discrepant withStandard Model predictions. They may be harbingers of new physics atan energy scale potentially accessible to direct discovery. We estimatethe sensitivity of future hadron colliders to the possible new particlesthat may be responsible for the anomalies: leptoquarks or Z's. A future100 TeV pp collider can cover all of the relevant Z' parameter spaceand has good coverage of the relevant leptoquark parameter space.
2018-04-05 (Thursday)
room 1.01, Pasteura 5 at 12:15
Alejandro Ibarra (Technical University of Munich)Dark matter decay via the gravity portal
We consider the Standard Model extended with a dark matter particle in curved spacetime, motivated by the fact that the only current evidence for dark matter is through its gravitational interactions, and we investigate the impact on the dark matter stability of terms in the Lagrangian linear in the dark matter field and proportional to the Ricci scalar. We show that this "gravity portal" induces decay even if the dark matter particle only has gravitational interactions, and that the decay branching ratios into Standard Model particles only depend on one free parameter: the dark matter mass. We study in detail the case of a light singlet scalar and discuss the prospects to observe its gravitationally induced decay.
2018-03-22 (Thursday)
room 1.01, Pasteura 5 at 12:15
Piotr Homola (IFJ PAN)Cosmic-Ray Extremely Distributed Observatory: novel astrophysical potential and beyond
The Cosmic-Ray Extremely Distributed Observatory (CREDO) project will use the hunt for particle cascades from deep space as a vehicle for a unique ``bottom-up'' approach to scientific research. By engaging the non-specialist public of all ages as ``citizen scientists'' we will create an opportunity for lifelong learning for individuals as well as for cooperation and the sharing of common educational tools amongst institutions. The discoveries of these citizen scientists will feed directly into a pioneering new area of scientific research oriented on Cosmic Ray Ensembles (CRE). The detection (or non-detection) of such particle groups promises to open up a new method for exploring our universe. The opportunities this would create for cross-disciplinary research are significant and beneficial for individuals, networks of institutions and the global communities of both professional scientists and science enthusiasts.
2018-03-01 (Thursday)
room 1.01, Pasteura 5 at 12:15
Robert Szafron (Technical University Munich)Enhanced corrections in rare B-meson decays
In my talk, I will report on the computation of QED radiative corrections to the rare leptonic decay of strange B mesons. In the previous literature, only the QED corrections above the mb scale have been evaluated. I will outline an approach to compute corrections below the mb scale using soft-collinear effective theory. It reveals an unexpected enhancement due to a "non-local annihilation" effect. Moreover, exchange of a soft fermion generates additional logarithmic enhancement. Therefore, the effect is interesting not only for the phenomenological reasons but also illustrates the intricate structure of QED in bound states. The talk will be based on Phys.Rev.Lett. 120, 011801 (arXiv:1708.09152).