Beyond The Standard Model: Some Aspects of Supersymmetry and Extra Dimension

In this thesis we have explored some of the phenomenological aspects of warped/flat extra dimensional theories and their interface with supersymmetry. We study the numerical impact of compactified warped extra dimension on the processes gg -> h and h -> \gamma \gamma, which are of paramount importance in the context of Higgs search at the LHC. We compute radiative correction to the lightest neutral Higgs mass induced by the Kaluza-Klein (KK) towers of fermions and sfermions in a supersymmetric warped extra dimension model. Next we make a more formal renormalization group study of a supersymmetric model embedded in a flat 5d scenario, with the inverse radius of compactification of the fifth dimension at the TeV scale. We show that radiative electroweak symmetry breaking can be achieved in this scenario. We construct for the first time, the 5d versions of the often displayed 4d m_0-M_{1/2} plots.