New vector like fermions in extensions of MSSM and their searches at LHC

by Dr Roberto Moreira (UFABC, Brazil)

Tuesday Sep 25, 2012, 8:00 AM → 9:00 AM Pacific/Honolulu

417A (Watanabe Hall)

Considering the most recent data from the LHC (pointing to a Higgs boson mass around 125 GeV), we find a tension in the supersymmetric models framework, because the lightest Higgs boson of the Minimal Supersymmetric Standard Model (MSSM) has an upper mass bound about m_Z at the tree level. Radiative corrections with heavy super-partners can yield the observed value of m_h but lead to the little hierarchy problem. To solve that, we consider a class of models beyond MSSM with a fourth generation of vector-like fermions (in complete multiplets of SU(5), maintaining the perturbative gauge coupling unication in GUT models) that easily can raise the Higgs boson mass naturally while remaining consistent with experimental constraints of oblique parameters. We discuss the phenomenology of three different scenarios characterized by the content of new vector like particles. The collider phenomenology is sensitive to the mixing of new particles with SM particles. To satisfy flavor constraints, we assume that only third generation particles mix with the new particles. We evaluate rates and event topologies from the pair production of the lightest new quarks at the LHC.