Looking for Technicolor in ATLAS

Developed since the early 60's, the Standard Model is a powerful theory describing physics at the subatomic scale. It has achieved great successes, such as the prediction of the top quark, discovered in 1995 at Tevatron. However one of the central piece of this model, the Higgs boson, has still not been observed. What if it is not discovered at the Tevatron or LHC? What type of new physics will we look for, and what will this imply? This talk will present an alternative mechanism for the breaking of the electroweak symmetry: Technicolor. In this theory, the Higgs mechanism is replaced by new strong interactions. This solves some of the issues of the Standard Model, such as the Hierarchy problem. In summary, this theory introduces new QCD-like interaction, as well as a new set of fermions, called techniquarks, to generate the mass of the W and Z. Early Technicolor models have been ruled out by precision electroweak measurements. We will describe more recent types of Technicolor models, which pass those tests, and are currently searched for at collider experiments. After a brief introduction to technicolor models, we will focus on the current experimental status. We will then describe what searches will be conducted in the LHC experiments in order to discover or exclude Technicolor.