Here, tan β ≈ 5–50 is the ratio of Higgs field vacuum expectation values v u / v d and m H d is the down-Higgs soft breaking mass term. The Σ Σ d d ( i ) and Σ Σ u u ( j ) contain a variety of loop corrections labelled by indices i and j, the most important of which typically comes from the top-squarks.