ElectroWeak precision data: the minimal set of parameters
Abstract
Description
We show how precision electroweak data, assuming CP conservation and flavor universality, despite being sensitive to 20 dimension 6 operators, constrain severely only 9 combinations of them. We define a set of 7 oblique parameters $\hat S, \hat T, \hat U, V, X,W,Y$ which fully describe corrections to the leptonic observables. We add two additional parameters $δε_q, δC_q$ to take into account the most precise hadronic observables. Another parameter $δε_b$ is considered for the bottom quark if flavor universality is not assumed for the third generation of quarks. We show that the approximation is extremely satisfactory testing it on a set of random new physics models and on some famous $Z'$ gauge bosons.
To appear in the proceedings of the XLIst Rencontres de Moriond, ElectroWeak interactions and unified theories
To appear in the proceedings of the XLIst Rencontres de Moriond, ElectroWeak interactions and unified theories