Seminários

The Large Hadron Collider (LHC) at CERN is the highest energy collider ever built. The LHC therefore probes smaller distances and larger energies than ever accessible before. The top quark, discovered in 1995 at the Fermilab proton-antiproton collider Tevatron, is the most recent member of the known families of quarks. Although this particle appears to have no sub-structure and to be pointlike, its mass is of the order of a gold atom. Therefore it is believed to be an excellent candidate to be a portal to new physics beyond the Standard Model. The LHC is a top quark factory providing high-precision access to top quark physics. In this presentation I will present high precistion measurements of top quark properties and explore how they can be used to search for exotic physics. I will put particular emphasis on searches for Dark Matter which represents one of the main unresolved questions in particle physics today.

The analysis of data collected by the CMS experiment at a collision energy of 13 TeV for the Run 2 provided confirmation of the existence of a Higgs boson with a mass of 125 GeV and all the measurements about its properties were found consistent with the Standard Model predictions. Nevertheless a full reality of the Higgs mechanism to give mass to the particles cold not be established wit the statistics of Run 2 data and at the same time the Run 2 data analysis opened a wide scenario for searches for physics beyond Standard Model, even in the Higgs sector. An upgrade program is planned for the LHC which will smoothly bring the luminosity up to or above 5x10^34cm^-2s^-1 sometimes after 2020, to possibly reach an integrated luminosity of 3000 fb-1 at the end of that decade. For this ultimate scenario, called Phase-2, when LHC will reach the High Luminosity phase (HL-LHC), the CMS detector will be upgraded to fully exploit the highly-demanding operating conditions and the delivered luminosity (giving up to 200 events). Precision measurements in the Higgs sector are planned and prospective studies have been done in the last year to explore the CMS potential in the Higgs sector in the high luminosity scenario of the LHC. The latest results will be summarized in this seminar. In addition new future projects involving larger and more powerful accelerators would provide more precise measurements in the Higgs sector and shed light on the self-couplings of the Higgs boson and more, etc.; current studies will be briefly described.

The second data taking period of CERN's LHC has ended, having delivered about 150/fb worth of pp collisions at the record energy of 13TeV, as well as collisions involving heavy ions. This exceeds by a factor 5 the amount of data recorded during the first datataking period, and at a collision energy almost twice higher. With part of these data analyzed, a good number of results has been already extracted, with considerable improvement in sensitivity. I will present a selection of recent results from the LHC, as well as future prospects, with focus on the flavor sector.