Parts | Days | Selection | Search | Updates | Downloads | Help
T: Fachverband Teilchenphysik
T 4: Supersymmetrie 1
T 4.2: Talk
Monday, March 24, 2014, 11:15–11:30, P4
Search for direct stop production in final states with jets, b-jets and missing transverse momentum with the ATLAS detector — •Claudia Giuliani and Francesca C. Ungaro — Albert-Ludwigs-Universität, Freiburg, Deutschland
Supersymmetry is one of the most promising extensions of the Standard Model of particle physics. It solves the hierarchy problem for the Higgs boson mass and gives a good candidate for the dark matter in the universe. Following naturalness arguments, the gluino should not be heavier than about 2 TeV and the supersymmetric partner of the top quark, the stop, should have a mass below about 1 TeV. To date, no supersymmetric signal has been found and tight limits have been placed on gluino masses. Searches for third generation squarks were already able to exclude large areas of the parameter space. In the hope to find the partners of the top and bottom quarks below the naturalness threshold of 1 TeV, many efforts are ongoing to explore thoroughly the available phase space for different decay channels.
The focus of this presentation is on the search for direct stop production in final states with jets, b-tagged jets and and large missing transverse momentum.
The 2012 ATLAS dataset is analysed, which corresponds to an integrated luminosity of 20.3 fb−1 of LHC pp-collisions at 8 TeV.
In particular, the top background estimate and the signal selection optimisation, done to increase the sensitivity in a simplified model where the stop decays to top plus neutralino with a branching ratio of 100%, are discussed.