Seminarium Fizyki Wielkich Energii

Friday 13 Mar 2020, 10:15 → 11:30 Europe/Warsaw

Room: B2.38 (Wydział Fizyki UW)

Aleksander Filip Żarnecki (University of Warsaw), Jan Królikowski (IFD UW), Katarzyna Grzelak (IFD UW)

10:15 → 10:45 Sensitivity to new physics scenarios in invisible Higgs boson decays at CLIC

Possibility of measuring invisible Higgs boson decays is studied for CLIC running at 380 GeV and 1.5 TeV. The analysis is based on the WHIZARD event generation and fast simulation of the CLIC detector response with DELPHES. Expected limits on the invisible decays of the 125 GeV Higgs boson are estimated, as well as the cross section limits for production of an additional neutral Higgs-like scalar, assuming its invisible decays, as a function of its mass. Extracted model-independent branching ratio and cross section limits are then interpreted in the framework of the vector-fermion dark matter model to set limits on the mixing angle between the SM-like Higss boson and the new scalar of the "dark sector".

Speaker: Mr Krzysztof Mekala (University of Warsaw)

10:45 → 11:15 Optimizing top-quark threshold scan at CLIC using genetic algorithm

One of the main goals of the future e+e- colliders is to measure the top-quark mass and width in a scan of the pair production threshold. Yet, the shape of the threshold cross section depends also on other model parameters as the top Yukawa coupling and the strong coupling constant. We demonstrate that even in the most general approach the top-quark mass can be extracted with statistical precision of the order of 20 to 30 MeV. When optimising the mass measurement the statistical uncertainty can be reduced by about 30%, corresponding to factor of 2 increase in the integrated luminosity. We propose the optimisation procedure based on the genetic algorithm.

Speaker: Kacper Nowak (University of Warsaw)