The global electroweak fit and constraints on new physics with Gfitter

Abstract

The thourough investigation of radiative corrections allows to gain information on physics processes at higher energy scales than those directly accessible by current experiments. As a consequence, using electroweak precision measurements in conjunction with state-of-the-art SM predictions e.g. allows the estimation of a preferred mass range for the SM Higgs boson mass. Physics beyond the Standard Model can modify the relations between electroweak observables and their theoretical predictions. Such effects can be parametrized in terms of effective, so-called oblique parameters. A global fit of the electroweak SM, as performed with the Gfitter package, allows the determination of the oblique parameters and to probe physics models and to set constraints on their free parameters. In this paper we present updated results of the global electroweak SM fit taking into account the latest experimental precision measurements and the results of direct Higgs searches from LEP and Tevatron. Through the formalism of oblique parameters we obtain constraints on BSM models with universal and warped extra dimensions. In constrast, taking into account heavy flavor observables, (g-2), and dark matter predictions allows to constrain the parameter space of the minimal supergravity model (mSugra).