Tez özetleri Astronomi ve Uzay Bilimleri Anabilim Dalı

Higgs Mediated Double Flavour Violating Top Decays in Effective Theories

Top quark’s which has a mass comparable with electro-weak symmetry breaking scale its dynamic behavior is pretty limited although there is a known fact that it is the heaviest particle. In Standard Model (SM), top quark production cross section is valued with a ~%15 level uncertainty and it is assumed that top quarks W boson and b quark decaying almost %100 of time. Because of its extremely heavy mass, we can think that top quark will be more related with new physics rather than other fermions. Because of this, top quark physics can be accepted as an important window in order to research physics beyond the SM. Although many of top quark’s properties Tevatron-Fermilab in Chicago-ABD has been researched more reliable results will be attained in the experiments at LHC. LHC will operate like a top quark factory and in the first stage 8 million  will be produced and in consequent years it is expected that the number of events created will be 18 million. Other studies will be done in the next generation  linear colliders.

In  top quark transitions the possibility of detecting double flavor violation has been researched as an independent method by using effective Lagrangian approach. High sensitivity measurements and low energy data on the current experimental limits are used in order to constrain  and  vertices and then also to calculate branching ratio . If  is  level in the Standard Model, at Higgs mediated double flavor violation top quark decay branching ratio for  can occur at the values of . These values are at the interval values reached in CERN Large Hadron Collider (LHC).