An effective guide to beyond the Standard Model physics

Effective Lagrangians with dimension-six operators are widely used to analyse Higgs and other electroweak data. We show how to build a basis of operators such that each operator is linked to a coupling which is well measured or will be in the future. We choose a set of couplings such that the correspondence is one-to-one. The usual arbitrary coefficients in front of operators can be constrained quite directly using experimental data. In our framework, some important features of the Lagrangian are transparent. For example, one can clearly see the presence or absence of correlations among measurable quantities. This may be a useful guide when searching for physics beyond the Standard Model.