Seminars WS19/20

Tuesday, January 21, 2020, 4:30pm (28B110)

Peter Fackeldey (RWTH)

Higgs pair production status at LHC (Run II)


The measurement of the di-Higgs boson production is a direct test of the electroweak symmetry breaking in the standard model of particle physics (SM). The coupling strength between three Higgs bosons (self-coupling) determines the shape of the Higgs potential and thus the vacuum stability of the universe. The current Run II status of ATLAS and CMS is presented with results interpreted in non-resonant (SM) and resonant (BSM) Higgs pair production.




Tuesday, January 14, 2020, 4:30pm (28B110)

Dirk Krücker (DESY Hamburg)

The modern Times of HEP Analysis


Deep Learning and the common data science tools have fundamentally changed the style of data analysis in High Energy Physics. The latest b-quark taggers used by the CMS experiment at the LHC are large Neural Networks and many of the legacy Run II publication on searches for New Physics will use Machine Learning. The talks introduces the use of Neural Nets in CMS with examples from b-jet tagging and searches for Supersymmetry.




Tuesday, December 17, 2019, 4:30pm (28B110)

Matthias Schröder (KIT)

The Higgs Boson at the Top: ttH Status and Future


In the Standard Model (SM) of particle physics, the Higgs boson is deeply related to the mechanism that creates the masses of the elementary particles. A precise measurement of the Higgs boson properties and couplings offers a unique probe of this mechanism, and thus, plays a crucial role in testing the predictions of the SM and discovering potential new physics.
The coupling of the Higgs boson to the heaviest known quark, the top quark, is particularly exciting, as it is large, and therefore, has a strong impact on the consistency of the SM as well as on many new physics models. The best direct measurement of the top-Higgs coupling is achieved at the LHC in proton-proton collision events where a top quark-antiquark pair is produced in association with a Higgs boson (ttH production).
In the presentation, the first observation of the ttH production by the CMS experiment in 2018, which was achieved by combining analyses in several decay channels of the Higgs boson, will be reviewed, and an overview of the current status will be presented. As an example, a recent result in the bb decay channel of the Higgs boson will be highlighted, which establishes evidence for ttH production in this channel alone. The analysis benefits from a larger dataset, improvements of the CMS detector, as well as refined analysis methods exploiting advanced machine-learning techniques. Finally, prospects for future ttH measurements at the LHC and beyond will be discussed.




Tuesday, December 03,2019, 4:30pm (28B110)

Sascha Caron (Radboud University, Nikhef)

Expanding the search for new physics via data-derived signal regions, automatisation and machine learning




Tuesday, November 19, 2019 4:30pm (28B110)

Michal Bluj (Warsaw)

Testing CP structure of Higgs couplings at LHC


Violation of the CP symmetry is one of the Sakharov conditions required to explain the baryon asymmetry observed in Universe. Although the CP violation is already built in the Standard Model via quark mixing, its strength is not sufficient to explain the magnitude of the observed baryon asymmetry. This motivates searches for new sources of CP violation in the Higgs sector.




Tuesday, October 15, 2019, 4:30pm (28B110)

Kumiko Kotera (Paris)

The Giant Radio Array for Neutrino Detection


The Giant Radio Array for Neutrino DetectionAbstract: The Giant Radio Array for Neutrino Detection (GRAND) project aims to detect ultra-high-energy cosmic neutrinos, cosmic rays, and gamma rays with a radio antenna array deployed over a total area of 200000 km2 in mountainous regions, in several favorable locations around the world. The strategy of GRAND is to detect air showers above 10^17 eV that are induced by the interaction of high-energy particles in the atmosphere or in the Earth crust, through its associated coherent radio-emission in the 50-200 MHz range. In its final configuration, GRAND plans to reach a sensitivity of ~10-10 GeV cm-2 s-1 sr-1 above 5*1017 eV and a sub-degree angular resolution. The 300-antenna pathfinder array, GRANDProto300 is planned to be deployed in 2021. It aims at demonstrating autonomous radio detection of inclined air-showers, and make measurements of the composition and the muon content of cosmic rays around the ankle energy. In this talk, we will show preliminary designs and simulation results, plans for the ongoing, staged approach to construction, and the rich research program made possible by the proposed sensitivity and angular resolution.