Oblique Parameters and Extra Generations via OPUCEM

Abstract

Recent improvements to OPUCEM, the tool for calculation of the contributions of various models to oblique parameters, are presented. OPUCEM is used to calculate the available parameter space for the four family Standard Model given the current electroweak precision data. It is shown that even with the restrictions on Higgs boson and new quark masses presented in the 2011 autumn conferences, there is still enough space to allow a fourth generation with Dirac type neutrinos. For Majorana type neutrinos, the allowed region is even larger. The electroweak precision data also favors non-zero mixing between light and fourth generations, thus effectively reducing current experimental limits. Additionally, calculations with OPUCEM show that even 5th and 6th generations are compatible with the existing electroweak precision data, with a probability comparable to or higher than the Standard Model with 3 generations.

11 pages, 21 figures, 5 tables - Version accepted by EPJ-C

References in corpus (5)

• Updated Status of the Global Electroweak Fit and Constraints on New Physics
• Less space for a new family of fermions
• Impact of the relatively light fourth family neutrino on the Higgs boson search
• OPUCEM: A Library with Error Checking Mechanism for Computing Oblique Parameters
• Observability of the Higgs Boson in the Presence of Extra Standard Model Families at the Tevatron

Cited by in corpus (3)

• The Physics Programme Of The MoEDAL Experiment At The LHC
• Combined search for the quarks of a sequential fourth generation
• Closing in on a perturbative fourth generation